Algis Kuliukas Hypothesis Of Hominid Evolution
Ross Macfarlane
I would like to understand better your particular hypothesis /
scenario of human evolution. Can you tell me if I have understood it
correctly?
Your scenario begins with an "aquarboreal" phase where the chimp /
homo LCA (? – how long ago?) becomes a bipedal wader. As far as
I can tell, you don't think this hominid would have been hairless like
modern humans (?) What other important adaptations do you think would
have evolved at this time?
Later (you have said 2.6MYA – based on?), 2 hominids have
evolved, 1 a fresh-water dweller & the other a coastal diver (how &
why did these evolve?) The latter at least of these may have been
hairless, but presumably they were closely related subspecies, as they
were able to interbreed & produce a fertile hybrid human precursor.
How am I doing?
Then presumably the hybrid ape further evolved into a form more like
modern humans, but some of your posts suggest you still see early Homo
as semi-aquatic. Is this so, & if so what types of aquatic
adaptations, both morphological & behavioural, did they exhibit, & how
long did they persist?
Final question - when did the hominids become savannah-adapted?
Out of interest…
Ross Macfarlane
Algis Kuliukas
> Algis,
>
> I would like to understand better your particular hypothesis /
> scenario of human evolution. Can you tell me if I have understood it
> correctly?
I suspect you are trying to take the mick, but ok, seeing you ask...
> Your scenario begins with an "aquarboreal" phase where the chimp /
> homo LCA (? – how long ago?) becomes a bipedal wader. As far as
> I can tell, you don't think this hominid would have been hairless like
> modern humans (?) What other important adaptations do you think would
> have evolved at this time?
That's about right, Ross. I agree with Marc Verhaegen that the LCA of
Gorilla/Pan/Homo was probably an 'aquarboreal' ape. I go along with
the accepted dates for this at around 7-5mya and I think it probably
lived around NE Africa on the Tethys coastline which was rapidly
changing around that time with many flood/dessication cycles going on.
I think it was rather orang-like but waded when necessary through
swamps/mangroves and other forest weetlands habitats. It didn't have
any particularly human-like specialisations for bipedalism but as a
wading ape it didn't really need any of those.
I think it is a logical starting point for Gorilla - which then got
larger and more terrestrial and less argoreal; Pan - which got much
more terrestrial and slightly less arboreal; and Homo - which got much
less arboreal, more terrestrial and slightly more aquatic. Most other
models of the LCA seem to assume it was like a chimp - as did I before
Orrorin was discovered making me realise Marc's ideas on this were
much more likely to be correct than I had thought previously.
> Later (you have said 2.6MYA – based on?), 2 hominids have
> evolved, 1 a fresh-water dweller & the other a coastal diver (how &
> why did these evolve?) The latter at least of these may have been
> hairless, but presumably they were closely related subspecies, as they
> were able to interbreed & produce a fertile hybrid human precursor.
> How am I doing?
I use 2.6my merely as a kind of cut off between pre-Homo
aquarboreality and Homo-like water-side adaptation. (Basically
assuming the first true Homo were different, not arboreal but
water-side living hominids)
My model needs at least two types of hominids, yes. You shouldn't be
surprised about that. Most authorities now see that there was a
significant radiation of hominids after the adoption of bipedalism.
Bipedalism, once emerged, would seem to have given certain advantages.
I see bipedal origins being tied up with wading but once a threshold
was crossed making bipedalism the favoured mode of locomotion on land,
it would clearly give lots of non-aquatic advantages too.
I think there was therefore a widespread radiation of bipedal hominids
giving rise to the many paleospecies we see in the fossil record.
Some of these - I call them river apes - inhabited gallery forests and
became adpated to fresh-water habibats. Perhaps these were the gracile
a'piths which seem to be associated with gallery forest habitats. As
Africa dried and forests shrank these would, paradoxically become more
dependent on water and probably lost body hair to enhance sweat
cooling.
Others found themselves marooned in Danakil before that region became
flooded. This group (I wouldn't call them a species because, as you
anticipate, I think they are likely to have interbred with the river
apes) became more terrestrial because of the lack of land predators on
their island habitat and became more aquatic too having to get much of
their food from foraging todail waters and eventually diving along the
shorelines. The model would argue that these were more salt-water
tolerant and 'marine' too. I accept that there is, as yet, no fossil
evidence whatsoever for these hominids but then who has gone to
Danakil to look for them? The evolution of these hominids off the
African mainland would explain how Homo has avoided the baboon marker
implying an Asian origin for Homo sapiens.
Yes, nakedness, I think evolved later but who knows. There's nothing
in my model that needs it to have evolved earlier or later.
And, yes, after about 3my of separation the model postulates that the
two groups came back together and interbred. So, you are doing vey
well, Ross.
> Then presumably the hybrid ape further evolved into a form more like
> modern humans, but some of your posts suggest you still see early Homo
> as semi-aquatic. Is this so, & if so what types of aquatic
> adaptations, both morphological & behavioural, did they exhibit, & how
> long did they persist?
Yes, I think the hybridisation caused the Homo sapiens speciation and
did so recently and very rapidly, including the change from 48 to 46
chromosomes and thus rapid genetic isolation. I guess this happenned
between 500kya and 300kya. This was a true hybrid, mixing the
different aquatic traits of the parental groups and generating this
rather odd quasi-semi-aquatic hominid we see in ourselves.
I think it is likely that as a hybrid the novo species was adapted to
a hybrid zone - possibly an estuarine habitat to begin with.
Hybridisation is known to produce many differnt genetic combinations
and so the model would postulate that this gave the perceived
phenomenon of rapid evolution that seems to have occured late in the
human story. Brain growth and the rapid evolution of language is seen
to have occured at this time. Hybridisation is one solution to the
Gould-Dawkins dilemma - the question of Saltatory leaps in evolution.
Homo sapiens thus quickly evolved as the speaking - and thus
intelligent in the modern sense - cultural animal he is today and
therefore was able to easily out-compete parental homo species and, as
genetic isolation was built in from the start, almost no genetic
mixing was able to take place. Therefore this part of the model
consists of an extreme (pure) form of the Out of Africa II
(replacement) model.
They continued to live in predominently water-side niches but their
population expanded rapidly. As they did so they expanded along rivers
and coastlines into every conceivable nook and cranny on the planet -
mountain regions, polar regions - yes, even dry savannahs and deserts
- always replacing previous hominids as they went.
> Final question - when did the hominids become savannah-adapted?
Never.
Algis Kuliukas
Jim McGinn
Pure pseudo-science. Your ignorance of the nature of speciation has
provided you to false confidence to dimwittedly employ hybridization
as a causal process that can, supposedly, explain human bevavioral
(culture) diversity.
>
> I think it is likely that as a hybrid the novo species was adapted to
> a hybrid zone - possibly an estuarine habitat to begin with.
> Hybridisation is known to produce many differnt genetic combinations
> and so the model would postulate that this gave the perceived
> phenomenon of rapid evolution that seems to have occured late in the
> human story. Brain growth and the rapid evolution of language is seen
> to have occured at this time. Hybridisation is one solution to the
> Gould-Dawkins dilemma - the question of Saltatory leaps in evolution.
It's not a dilemma, you idiot. Saltatory leaps are explained
perfectly well by shifts in climate. Shifts in climate dictate shifts
in the biota and its species.
>
> Homo sapiens thus quickly evolved as the speaking - and thus
> intelligent in the modern sense - cultural animal he is today
So, for you intelligence, language, and culture are forgone
conclusions. This exemplifies how simpleminded you truly are. It's
like you're retarded. The whole goal of any examination into human
origins is to explain the origins of behaviors like intelligence,
language, and culture which are so prominent in our species and
relatively nonexistent in other species (and nonexistent on this
planet until an extremely recent 8 to 10 mya). How stupid do you have
to be to offer an explanation for hominid evolution and then just
gloss over the part that should be the focus of your explanation. And
it's no excuse that the savanna dipwads make the same omission.
Let's remember folks. We're supposed to be explaining HUMAN
evolution. Not nonexistent swimming monkey evolution. Not some
animal that magically begins using tools millions--on some treelesss
savanna that didn't even exist at this time--years before it has the
intellectual capacity to even begin to use tools.
Humans are psychologically complex, communicative, highly conscious.
These are the traits that need to be explained. It's so funny how you
idiots spend all this time discussing traits like hairlessness. Use
your brain for a change. Once we have an animal that is
psychologically complex, communicative, highly conscious, and that has
intellectual capacity then it is very easy to explain hairlessness by
way of the fact that this animal would be wearing clothes and sitting
around campfires. Duh.
Marc Verhaegen
news:77a70442.03050...@posting.google.com...
> That's about right, Ross. I agree with Marc Verhaegen that the LCA of
Gorilla/Pan/Homo was probably an 'aquarboreal' ape. I go along with the
accepted dates for this at around 7-5mya and I think it probably lived
around NE Africa on the Tethys coastline which was rapidly changing around
that time with many flood/dessication cycles going on. I think it was
rather orang-like but waded when necessary through swamps/mangroves and
other forest weetlands habitats. It didn't have any particularly human-like
specialisations for bipedalism but as a wading ape it didn't really need any
of those.
I agree of course, but with some nuances: the hominid LCA ca.8 Ma probably
had shorter arms than living orangs, had more humanlike feet, was more
bipedal than orangs, IMO omnivorous & durophagous (thick enamel, tool use:
coco & other nuts...), wading & suspensory (& possibly surface swimming?) in
coastal forests.
> I think it is a logical starting point for Gorilla - which then got larger
and more terrestrial and less arboreal; Pan - which got much more
terrestrial and slightly less arboreal; and Homo - which got much less
arboreal, more terrestrial and slightly more aquatic. Most other models of
the LCA seem to assume it was like a chimp - as did I before Orrorin was
discovered making me realise Marc's ideas on this were much more likely to
be correct than I had thought previously.
:-)
> I use 2.6my merely as a kind of cut off between pre-Homo aquarboreality
and Homo-like water-side adaptation. (Basically assuming the first true Homo
were different, not arboreal but water-side living hominids)
Yes, Homo (less climbing, more wading-swimming-diving) seems to be the
product of the Ice Ages, cf. our Continental Shelf hypothesis: MV & Stephen
Munro 2002 "The continental shelf hypothesis" Nutrition &Health 16:25-27
.....
> Yes, nakedness, I think evolved later but who knows. There's nothing in my
model that needs it to have evolved earlier or later.
Yes, we have no fossilized hominids furs.
......
> > Final question - when did the hominids become savannah-adapted?
> Never. Algis Kuliukas
:-) Obvious, no?
Marc
Algis Kuliukas
I employed hybridisation as a mechansism of speciation that provides
rapid genetic isolation through karyotpic change. I think the evidence
is consistent with that. Human evolution does appear to have 'shifted
gear' with the advent of Homo sapiens and I think that is consistent
with the hybridization idea too.
I don't claim that it explains human cultural diversity. That, I
think, is the result of rapid mimetic evolution which has occurred
ever since modern humans first became established around 250kya.
> > I think it is likely that as a hybrid the novo species was adapted to
> > a hybrid zone - possibly an estuarine habitat to begin with.
> > Hybridisation is known to produce many differnt genetic combinations
> > and so the model would postulate that this gave the perceived
> > phenomenon of rapid evolution that seems to have occured late in the
> > human story. Brain growth and the rapid evolution of language is seen
> > to have occured at this time. Hybridisation is one solution to the
> > Gould-Dawkins dilemma - the question of Saltatory leaps in evolution.
>
> It's not a dilemma, you idiot. Saltatory leaps are explained
> perfectly well by shifts in climate. Shifts in climate dictate shifts
> in the biota and its species.
I said 'one solution' not 'the only solution'. Of course climatic
change could also play a part. They are not mutually exclusive. On the
contrary. I start with the observation that humans have a different
karyotype to other hominids and the molecular data indicates a rather
recent speciation. I find the hybridisation model seems to be able to
neatly explain that. So how, where, when could such a hybridisation
have taken place?
Of course both could be related - ie a climatic change (or
specifically the start of the dessication of the Danakil sea) could
have resulted in both the two groups being drawn together and
simultaneously have cause a new habitat to have formed into which the
new species would have had an ideal opportunity to exploit.
> > Homo sapiens thus quickly evolved as the speaking - and thus
> > intelligent in the modern sense - cultural animal he is today
>
> So, for you intelligence, language, and culture are forgone
> conclusions. This exemplifies how simpleminded you truly are. It's
> like you're retarded.
It's so pleasant to deal with you, Jim. Thank you for being so kind.
I don't think they're forgone conclusions actually. I think human
so-called intelligence is very much related to language as it culture.
Apes are intelligent and they have culture, they do not have language.
That is the real difficulty that needs explaining.
I avoided discussing it (language evolution) in my model because I
simply don't have a very good idea as to how it evolved. If pushed,
I'd chose the ideas of Chris Knight et al (language evolving through
social cohesion and mutual trust) but I don't really understand it.
But then, of course, unlike you I am not a World Class Evolutionary
Theorist. By the way Chris Knight is a supporter of the AAH and his
model of language oririgns is entirely consistent with it.
I know the 'aquatic hybrid ape hypothesis' as I call it is very
limited. It merely tries to come up with a kind of 'aquatic' model
that is consistent with the data and answers some of the standard
criticism of it. I did this to try to make the AAH make sense to me if
you or anyone can see flaws I'm very keenand willing to change it.
Anyone who claims their model has all the answers is probably deluding
themslves I certainly make no such claim.
> The whole goal of any examination into human
> origins is to explain the origins of behaviors like intelligence,
> language, and culture which are so prominent in our species and
> relatively nonexistent in other species (and nonexistent on this
> planet until an extremely recent 8 to 10 mya). How stupid do you have
> to be to offer an explanation for hominid evolution and then just
> gloss over the part that should be the focus of your explanation. And
> it's no excuse that the savanna dipwads make the same omission.
>
> Let's remember folks. We're supposed to be explaining HUMAN
> evolution. Not nonexistent swimming monkey evolution. Not some
> animal that magically begins using tools millions--on some treelesss
> savanna that didn't even exist at this time--years before it has the
> intellectual capacity to even begin to use tools.
The evolution of human 'culture' and language appear to be relatively
recent things that happenned only after our speciation about
250-300kya. Therefore I make no excuse for focusing on the physical.
If we can't explain the physical foundation of hominids the any
cultural explanations are on very shaky ground.
Swimming monkeys (I'd prefer ape) do exist - they're quite common on
this planet. You and I both are part of that species.
> Humans are psychologically complex, communicative, highly conscious.
> These are the traits that need to be explained. It's so funny how you
> idiots spend all this time discussing traits like hairlessness. Use
> your brain for a change. Once we have an animal that is
> psychologically complex, communicative, highly conscious, and that has
> intellectual capacity then it is very easy to explain hairlessness by
> way of the fact that this animal would be wearing clothes and sitting
> around campfires. Duh.
Yes, Jim. We're all idiots except you.
Algis Kuliukas
Jim McGinn
> > > Yes, I think the hybridisation caused the Homo sapiens speciation
Let me get this straight, you think, "the hybridisation
caused the Homo sapiens speciation." What, exactly, does
this phrase mean. I don't think you even know what you're
saying. Hybridization is part of any process of
speciation. But you have the cart before the horse to
suggest that it is (or could be) causative.
> > > and
> > > did so recently and very rapidly, including the change from 48 to 46
> > > chromosomes and thus rapid genetic isolation.
You're just parroting back population biology terminology.
You have no more basis for theorizing "rapid genetic
isolation" for hominids than you do for kumquats. Who do
you think you're kidding.
I guess this happenned
> > > between 500kya and 300kya. This was a true hybrid,
That's good, don't you just hate those false hybrids.
mixing the
> > > different aquatic traits of the parental groups
Hopefully they're water soluble.
and generating this
> > > rather odd quasi-semi-aquatic hominid we see in ourselves.
I seem to have misplaced my odd quasi-semi-aquatic hominid.
Might you have a spare?
> >
> > Pure pseudo-science. Your ignorance of the nature of speciation has
> > provided you to false confidence to dimwittedly employ hybridization
> > as a causal process that can, supposedly, explain human bevavioral
> > (culture) diversity.
>
> I employed hybridisation as a mechansism of speciation that provides
> rapid genetic isolation through karyotpic change.
What in the world are you talking about. Have you
independently created a new science?
I don't know what "karyotpic change" is. But from what I can
gather it's a pretty safe bet that you've completely
miscomprehended it.
I think the evidence
> is consistent with that.
Consistent with what?
Human evolution does appear to have 'shifted
> gear' with the advent of Homo sapiens and I think that is consistent
> with the hybridization idea too.
I think you have no idea how idiotic you look to be
employing hybridization as a source of innovation. It's
like you're just creating you're own universe filled with
new and exciting biological mechanisms.
>
> I don't claim that it explains human cultural diversity. That, I
> think, is the result of rapid mimetic evolution
Rapid mimetic evolution? What is this and why didn't
all of the other species experience this "rapid mimetic
evolution." (I read the book in which Dawkins coined the
phrase meme. I cringed when I got to this part of the book.
Meme is just a fancy word for idea. So what you are actually
saying here is that our hominid ancestors got ideas and
these ideas drove their evolution. This is pseudo-scientific
BS.) You have a very creative understanding of how to apply
science.
which has occurred
> ever since modern humans first became established around 250kya.
Yeah, this must have been when they had their Rapid Mimetic
Evolution kick-off party.
>
> > > I think it is likely that as a hybrid the novo species was adapted to
> > > a hybrid zone - possibly an estuarine habitat to begin with.
> > > Hybridisation is known to produce many differnt genetic combinations
> > > and so the model would postulate that this gave the perceived
> > > phenomenon of rapid evolution that seems to have occured late in the
> > > human story. Brain growth and the rapid evolution of language is seen
> > > to have occured at this time. Hybridisation is one solution to the
> > > Gould-Dawkins dilemma - the question of Saltatory leaps in evolution.
> >
> > It's not a dilemma, you idiot. Saltatory leaps are explained
> > perfectly well by shifts in climate. Shifts in climate dictate shifts
> > in the biota and its species.
>
> I said 'one solution' not 'the only solution'.
You don't even use the terminology correctly and you're
calling it a solution. This is the usual nonsense.
Of course climatic
> change could also play a part. They are not mutually exclusive.
What are not mutually exclusive. (You haven't provided an
alternative explanation for the observed phenomenon, punctuated
evolution. All you're doing here, Algis, is throwing out big
words and deluding yourself into believing you know what you
are talking about.)
On the
> contrary. I start with the observation that humans have a different
> karyotype to other hominids
How is this relevant?
and the molecular data indicates a rather
> recent speciation.
What molecular data? Please be specific.
I'm aware of no such data.
I find the hybridisation model
> Oh! Now it's a "model." Well, well.
seems to be able to
> neatly explain that. So how, where, when could such a hybridisation
> have taken place?
Do you have a point here somewhere. You pulled hybridization
out of your ass and now you're asking me where it took place?
What are you talking about?
>
> Of course both could be related - ie a climatic change (or
> specifically the start of the dessication of the Danakil sea) could
> have resulted in both the two groups being drawn together and
> simultaneously have cause a new habitat to have formed into which the
> new species would have had an ideal opportunity to exploit.
?
>
> > > Homo sapiens thus quickly evolved as the speaking - and thus
> > > intelligent in the modern sense - cultural animal he is today
> >
> > So, for you intelligence, language, and culture are forgone
> > conclusions. This exemplifies how simpleminded you truly are. It's
> > like you're retarded.
>
> It's so pleasant to deal with you, Jim.
Why thank you, Algis.
> Thank you for being so kind.
Don't mention it.
> I don't think they're forgone conclusions actually. I think human
> so-called intelligence is very much related to language as it culture.
> Apes are intelligent
Apes are intelligent?
> and they have culture,
Apes have culture?
they do not have language.
> That is the real difficulty that needs explaining.
Yes, how come these highly intelligent and cultured apes aren't more chatty?
(Algis, BTW, apes are not intelligent. And their cultural
abilities are extremely limited by any measure. You can't even
get these simple facts straight in your head.)
>
> I avoided discussing it (language evolution) in my model because I
> simply don't have a very good idea as to how it evolved.
That never stopped you before.
(Language and intelligence could not have evolved separately.
There are completely complimentary and useless [or almost
useless] without each other.)
If pushed,
> I'd chose the ideas of Chris Knight et al (language evolving through
> social cohesion and mutual trust)
That's like saying wind is the result of air pressure and
vice versa. My point being that Chris Knight must be an
idiot (or you've misinterpreted him). Obviously language
evolved in the context of a social setting (It's useless
otherwise!).
but I don't really understand it.
> But then, of course, unlike you I am not a World Class Evolutionary
> Theorist.
No need to point out the obvious.
> By the way Chris Knight is a supporter of the AAH
Why am I not surprised.
> and his
> model of language oririgns is entirely consistent with it.
Is it? AAH is whackoism (same as SAT) and it's only your
ignorance that prevents you from realizing this.
>
> I know the 'aquatic hybrid ape hypothesis' as I call it is very
> limited. It merely tries to come up with a kind of 'aquatic' model
> that is consistent with the data and answers some of the standard
> criticism of it. I did this to try to make the AAH make sense to me
Let me get this straight. You read AAH. It didn't make
sense to you. So you decided you would try to make it make
sense. (I'm getting a good sense of your approach to science.)
> if you or anyone can see flaws I'm very keenand willing to change it.
You've done nothing but present a silly notion that
is immediately dismissable. It's not a model. It's
little more than a trivial notion that does little more
than advertise the ignorance of those who would be silly
enought to propose it.
> Anyone who claims their model has all the answers is probably deluding
> themslves I certainly make no such claim.
That's encouraging.
>
> > The whole goal of any examination into human
> > origins is to explain the origins of behaviors like intelligence,
> > language, and culture which are so prominent in our species and
> > relatively nonexistent in other species (and nonexistent on this
> > planet until an extremely recent 8 to 10 mya). How stupid do you have
> > to be to offer an explanation for hominid evolution and then just
> > gloss over the part that should be the focus of your explanation. And
> > it's no excuse that the savanna dipwads make the same omission.
> >
> > Let's remember folks. We're supposed to be explaining HUMAN
> > evolution. Not nonexistent swimming monkey evolution. Not some
> > animal that magically begins using tools millions--on some treelesss
> > savanna that didn't even exist at this time--years before it has the
> > intellectual capacity to even begin to use tools.
>
> The evolution of human 'culture' and language appear to be relatively
> recent things that happenned only after our speciation about
> 250-300kya.
How, exactly, do they "appear," as such.
(Fact: They do not appear one way or another. You just
interpret the data in a manner that fits your sensibilities.)
> Therefore I make no excuse for focusing on the physical.
> If we can't explain the physical foundation of hominids
And this supposedly involves them spending time wading in
waste deep water. This is what you call a model. And you
expect people to take this seriously.
> the any
> cultural explanations are on very shaky ground.
Uh, what does the phrase, "explanations are on very shaky
ground," mean? And what was the thought process that brought
you to this sweeping conclusion? I think what you are saying
is that culture is hard to model therefore we should just
ignore it and focus on bipedalism which is relatively easy
to model. Another words, you propose that we should let the
evidence lead us by the nose.
> Swimming monkeys (I'd prefer ape) do exist - they're quite common on
> this planet. You and I both are part of that species.
Isn't that special. :)
>
> > Humans are psychologically complex, communicative, highly conscious.
> > These are the traits that need to be explained. It's so funny how you
> > idiots spend all this time discussing traits like hairlessness. Use
> > your brain for a change. Once we have an animal that is
> > psychologically complex, communicative, highly conscious, and that has
> > intellectual capacity then it is very easy to explain hairlessness by
> > way of the fact that this animal would be wearing clothes and sitting
> > around campfires. Duh.
>
> Yes, Jim. We're all idiots except you.
It would seem. But don't lose hope. You may never get
smart but maybe someday I will get stupid.
Jim
Ross Macfarlane
> >
> > I would like to understand better your particular hypothesis /
> > scenario of human evolution. Can you tell me if I have understood it
> > correctly?
>
> I suspect you are trying to take the mick, but ok, seeing you ask...
No, I wasn't. I was trying to correct one of the problems with arguing
against your hypothesis of hominid evolution, which is trying to
understand what it is. What it is, as you've confirmed for me, is not
1 hypothesis, but several.
The result of not understanding this is that, in the same thread, 1
debate will develop arguing about whether any medium-sized
semi-aquatic mammals are hairless, & another debating whether or not
there is a selective advantage for hairlessness in water. If the
answer to the former question is no, then the answer to the latter
question would be moot, because it would imply that wading hominids
would probably not evolve hairlessness. However, your hypothesis is
(or seems to be) that the hairlessness probably evolved in a separate
event.
It's important for us to understand the lack of unity in the
hypothesis, because you (& Marc, & Pauline) tend to introduce
fragments of evidence piecemeal into the debate, & it if it isn't
clear which aquatic evolutionary event the evidence you proffer
relates to, it becomes difficult to understand your overall position.
So - bipedalism evolved as a response to wading in 1 evolutionary
event, & hairlessness / swimming / diving evolved in another putative
event. It takes a hybridisation to bring these 2 together, with
subsequent refining of the latter suite of characteristics in Homo. As
best as I can tell...
Hardy envisaged the aquatic ape theory as a sweeping scenario which
would capture & explain all the odd features of human morphology in 1
fell swoop. This was at a time over 40 years ago when the number of
hominid fossils & level of data surrounding them was small enough to
possibly sustain such a view.
You'll not be surprised that I view your hypothesis as firstly an
acceptance that this vision of a single over-arching aquatic
explanation has failed, and secondly as a construct developed in
response to a desire to maintain an aquatic ape hypothesis after
Hardy's vision has failed.
Crucial to the specifics of your particular hypothesis is the supposed
hybridisation event. To my knowledge, there is no paleontological
precedent, nor any theory of genetics or speciation amongst
multicellular organisms, which could accomodate an event as unlikely
as you describe.
Algis, it's my suspicion that your hypothesis began as an attempt to
create a hybrid between contradictory lines of evidence, and you
somehow twisted this philosophical construct, in your mind, into an
actual hybridisation event. My view on this is simply: if you have to
invent a unique & unprecedented biological occurence to sustain your
worldview, your worldview, in my opinion, simply can't be sustained.
>
> > Final question - when did the hominids become savannah-adapted?
>
> Never.
>
> Algis Kuliukas
Yes well... I had hoped you could display more objectivity than that,
but I'm afraid that response just sums up the direction of this whole
debate. It's going nowhere.
Algis, you may have better manners than Marc, but your hypothesis of
hominid evolution is no better, & the chances of you being ever able
to recognise it are no better either. So for now, I'm giving up on
exercises in futility...
Ross Macfarlane
Algis Kuliukas
> > >
> > > I would like to understand better your particular hypothesis /
> > > scenario of human evolution. Can you tell me if I have understood it
> > > correctly?
> >
> > I suspect you are trying to take the mick, but ok, seeing you ask...
>
> No, I wasn't. I was trying to correct one of the problems with arguing
> against your hypothesis of hominid evolution, which is trying to
> understand what it is. What it is, as you've confirmed for me, is not
> 1 hypothesis, but several.
Fair enough.
> The result of not understanding this is that, in the same thread, 1
> debate will develop arguing about whether any medium-sized
> semi-aquatic mammals are hairless, & another debating whether or not
> there is a selective advantage for hairlessness in water. If the
> answer to the former question is no, then the answer to the latter
> question would be moot, because it would imply that wading hominids
> would probably not evolve hairlessness. However, your hypothesis is
> (or seems to be) that the hairlessness probably evolved in a separate
> event.
Yes, that's right. The hypothesis is that moving through water was a
big factor in our evolution. Wading does not really require hair loss
to improve locomotor efficiency whereas swimming and diving do. As the
earliest bipeds lived at least 6mya and we know nothing about the
possible swimming abilities of any hominid apart from the fact that we
are, today, the strongest of all the primates it is logical to
seperate them, I think.
> It's important for us to understand the lack of unity in the
> hypothesis, because you (& Marc, & Pauline) tend to introduce
> fragments of evidence piecemeal into the debate, & it if it isn't
> clear which aquatic evolutionary event the evidence you proffer
> relates to, it becomes difficult to understand your overall position.
It is rather naive, I think, to expect any such "unity." Is there any
unity in the non-aquatic theories? Having said that I'd argue that
there is still probably more agreement within those that support the
AAH than those who do not. For example we have about dozen different
non-aquatic ideas on the origin of bipedality whereas all the
different proponents of aome form of AAH agree that wading was
probably the major factor.
I cannot speak for the others but for me it is pretty clear that
humans are physically different from other apes in ways that can be
explained some kind of adaptation to movement through water. That is
the starting point upon which a detailed model has to be built and, of
course, argued over. But that fundemental point is one you steadfastly
refuse to accept, even as a possibility. It seems to me that
aquasceptics have dug themselves into such a staunchly ant-AAH trench
that they cannot now even admit the most absurdly mild of
possibilities - in your case, even that our ancestors lived closer to
water than ape ancestors did. This is, in a way, understandable. You
clearly realise that admitting anything, on this slippery slope, would
be tantamount to an admission that the AAH was actually right all
along. Because if we lived by water more than chimps then, logically,
we must have moved through it more too. If we moved through it more,
then - through the laws of natural selection - clearly we'd have
become more adapted to it too. All you'd be left with then is pathetic
arguments about the 'degree' of aquaticism - claiming that these
aquatic pressures would have been so slight as to have made no
difference at all - an impossible position to hold.
> So - bipedalism evolved as a response to wading in 1 evolutionary
> event, & hairlessness / swimming / diving evolved in another putative
> event. It takes a hybridisation to bring these 2 together, with
> subsequent refining of the latter suite of characteristics in Homo. As
> best as I can tell...
No it doesn't need the hybridisation event. AFAIK I'm in a minority of
one on that idea. The basic model is simple enough: Wading led to
bipedalism and from the radiation that followed several hominids lived
contemporaneously. Any number of those could have possibly started
evolving in a Homo-like direction through swimming and diving. And
according to some AAH models (e.g. Elaine's own ideas I think) these
water-side living hominids could then have moved away from the water
to become purely terrestrial. My own varient is that two such aquatic
hominids interbred causing the Homo sapiens speciation and that the
water-side living never really stopped. I'd argue that human ancestors
were less aquatic than some of the other models but that it went on
for longer - in fact never really stopped.
> Hardy envisaged the aquatic ape theory as a sweeping scenario which
> would capture & explain all the odd features of human morphology in 1
> fell swoop. This was at a time over 40 years ago when the number of
> hominid fossils & level of data surrounding them was small enough to
> possibly sustain such a view.
Did he? Did he tell you that or did you read it somewhere? I was
speaking with his son just before I left England and that is not the
impression he gave me. Still, you know best.
Hardy had made an observation (sc fat in aquatic mammals) and made the
analogy with humans after reading about sc fat in humans. He realised
that the theory was controversial so kept it 'in the dark' for thirty
years before going public with it. He was, I feel, a rather more
modest than you portray him to be.
Remember he only posed the question "Was Man more aquatic int he
past?" More aquatic, note. The press knee-jerk reaction was to laugh
at the idea and assume he was talking about dolphins and mermaids.
Unfortunately, it seems that most PAs are still stuck in that
knee-jerk first impression even today.
All he was trying to do was to stimulate a debate and to encourage
scientists to test the theory. The response was appauling. Almost
nothing was done and the only words that were said were ridicule.
> You'll not be surprised that I view your hypothesis as firstly an
> acceptance that this vision of a single over-arching aquatic
> explanation has failed, and secondly as a construct developed in
> response to a desire to maintain an aquatic ape hypothesis after
> Hardy's vision has failed.
It's not that it failed. Hardy never had a model as such. He made no
predictions, had the barest timescale and offered no evidence other
than human anatomy analogies with aquatics. He was merely asking a
question so how could it have failed? The failure, if there was one,
must lie with the paleoanthropologists of the 1960s who simply ignored
it completely rather than having an ounce of proper scientific
curiosity about the idea.
Like Elaine Morgan, when I heard about the idea, I first thought 'yes,
there's something in this obviously' and then, when I realised that
the textbooks didn't even mention it as a possibility - 'so, what's
wrong with it?'
Because I had the benefit of Elaine's books and the chance to read the
debates on this forum I could see both sides of the argument. I could
see the strengths - like we are dependent on water, we can swim better
than apes and infants do seem relatively comfortable in water; and the
weaknesses - we're not really much like true aquatics, semi-aquatic
mammals are not really like us and although we are mainly fresh water
adapted we do have odd traits that indicate a marine link too. I made
it my goal to come up with a version of the AAH that kind of fitted in
the middle somewhere and made sense to both sides. (Optimistic, I
know! :-))
> Crucial to the specifics of your particular hypothesis is the supposed
> hybridisation event. To my knowledge, there is no paleontological
> precedent, nor any theory of genetics or speciation amongst
> multicellular organisms, which could accomodate an event as unlikely
> as you describe.
The hybridisation event is an explanation of the chromosome number
change and, simultaneously, our speciation. It also, for me, answers a
few contradictions about the AAH - like the fresh water/salt water
ones.
Speciation through hybridization is possible and there are a number of
workers who specialise in studying it. See Loren Reiseberg and Alan
Templeton for just two. It's not a popular theory but, as we AAH-ers
know only too well, that does not necessarily make it wrong.
> Algis, it's my suspicion that your hypothesis began as an attempt to
> create a hybrid between contradictory lines of evidence, and you
> somehow twisted this philosophical construct, in your mind, into an
> actual hybridisation event.
No. The other way round really. I started out thinking that the AAH
was right to some degree but that because it wasn't accepted I needed
to learn and understand the objections to it. I found that many of the
objections were very weak - based upon the straw man headline that
Hardy was claiming we evolved from mermaids or something. When I found
out that our chomosome numbers were different from all the other apes
I, seperately, started reading up on the theories that accounted for
that and found Templeton's hybridiation idea the most convincing.
Having incorporated hybridization into the model it dawned on me that
a hybridisation of ideas is what we really need here. All the
brilliant minds that have been working on these problems over the
years cannot be wrong. I found that it is possible to look at two
different views about human evolution and find some common thread or
find that if you only change one slight assumption things can come
together - so 'a hybrid of models about a hybrid of hominids' came to
mind.
My model is probably rubbish, I know that. But it's the best I have
been able to come up with so far and I am committed to changing it
whenever convincing new evidence comes up.
> My view on this is simply: if you have to
> invent a unique & unprecedented biological occurence to sustain your
> worldview, your worldview, in my opinion, simply can't be sustained.
The hybridisation event is not necessary in the AAH but I have yet to
read a more convincing model for chromosome number change. And, Ross,
we do have different numbers of chromosomes than the other great apes.
The AAH makes more sense to me with hybridisation in the model, that's
all I can say at the moment.
> > > Final question - when did the hominids become savannah-adapted?
> >
> > Never.
>
> Yes well... I had hoped you could display more objectivity than that,
> but I'm afraid that response just sums up the direction of this whole
> debate. It's going nowhere.
There are aquasceptics that would dismiss the savannah adaptation idea
as strongly as I do.
> Algis, you may have better manners than Marc, but your hypothesis of
> hominid evolution is no better, & the chances of you being ever able
> to recognise it are no better either. So for now, I'm giving up on
> exercises in futility...
You're entitled to your opinion, of course. In return may I just say
that for a moment I thought you were an objective-minded poster to
this forum but you've rather disappointed me with your rigid
aquascepticism. You are, I think, about as objective as Clarke and
Love although I would grant that you do argue more convincingly than
they do.
Algis Kuliukas
Abazagaroth
> rmac...@alphalink.com.au (Ross Macfarlane) wrote in message news:<18fa6145.03050...@posting.google.com>...
> > against your hypothesis of hominid evolution, which is trying to
> > understand what it is. What it is, as you've confirmed for me, is not
> > 1 hypothesis, but several.
>
> Fair enough.
Hypotheses built on hypotheses built on more hypotheses lend little to
credibility, and only end up appealing to those credulous to the idea
in the first place (and only incite the flames of those incredulous to
the idea to begin with).
This was the point of Langdon's JHE paper 6 years ago. These aquatic
theories are theories of everything and nothing. They try to explain
everything, and whenever any part is shown to be incorrect, equivocal,
or even just unlikely, there is the cry that this doesn't matter,
because its only a "minor" part of the theory in the first place.
This is why people get so frustrated with Marc, as he has this down
pat. Whenever someone points out a single problem, he turns the
problem back out onto the overarching theory in an attempt to minimize
the importance of the original point, and then claim "no one has
presented 1 argument against" his scenario (because in his mind the
original point is no longer an "argument against" since he has
deflected it back onto the overarching theory which is still
supporting by all the other pieces of "evidence"). It doesn't matter
if some, many, most, or even all of the points in support of the
theory have been discredited or shown to be equivocal, since he
refuses to stop using this - at best - illogical and naive method or -
at worst - intellectually dishonest method.
It is perfectly fine to have an umbrella theory. You're welcome to it.
However, it is only as strong as its weakest point. It could still be
correct, almost anything is possible, but you can't dismiss everything
else while latching onto one point, and then use that single point as
the bar of credulity of the theory.
In addition, by recognizing your ideas as multiple hypotheses, you
should be recognizing that the same is true of *every* larger idea in
reconstructing human origins. Just like it is unfair to brand all
aquatic based ideas based on one point of data or on the evaluation of
one particular brand of aquaticism, the same is true for then
"savanna" straw man that most of the aquatic crowd likes to attack.
Think about the AAT list. Think about how many times I pointed out
that there is no "savanna theory", that the concept being attacked
there was just a straw man (both in the interpretation of what savanna
meant and in the idea there is some larger "theory" tied to it that is
widely accepted), and that there was no "standard PA" that kept being
attacked there. Paleoanthropology is a specialized subfield of
physical anthropology, and the fact that a myriad of intro phys anth
classes regurgitate the same stuff from 20-50 years ago because both
the professors teaching those classes and those that wrote the intro
books are not paleoanthropologists does not mean there is any
"standard PA". Might as well do your academic research from an
encylcopedia britanica if that is the definition of "standard". Now,
what happened when I pointed this out? Aside from Marc posting some
link to a news blurb written by a reporter (which only served to prove
the point of the inappropriate straw man interpretation of the
supposed "rival" savanna theory), several times you and Pauline and
maybe one or two others responded that they understood, or that was
interesting, that they didn't realize that, whatever. Then two days
later all would revert to using the same snipes against "savanna
theory" and "standard PA" that you claimed as inappropriate from the
"aquasceptics" that sniped at the various AAT/AAH strawmen.
> > The result of not understanding this is that, in the same thread, 1
> > debate will develop arguing about whether any medium-sized
> > semi-aquatic mammals are hairless, & another debating whether or not
> > there is a selective advantage for hairlessness in water. If the
> > answer to the former question is no, then the answer to the latter
> > question would be moot, because it would imply that wading hominids
> > would probably not evolve hairlessness. However, your hypothesis is
> > (or seems to be) that the hairlessness probably evolved in a separate
> > event.
>
> Yes, that's right. The hypothesis is that moving through water was a
> big factor in our evolution. Wading does not really require hair loss
> to improve locomotor efficiency whereas swimming and diving do. As the
> earliest bipeds lived at least 6mya and we know nothing about the
> possible swimming abilities of any hominid apart from the fact that we
> are, today, the strongest of all the primates it is logical to
> seperate them, I think.
Get rid of "require". There is no requiring of hair loss, for any
reason. Evolution does not proceed from what is "most adaptive" (i.e.
it doesn't follow a predefined course assuming several preceeding
factors) all the time, and its only an assumption that it does so much
of the time. Selection is not random, but that doesn't mean you can
set up some premises and follow from them using opinions of what is
going to be more or less adaptive, particularly if you only have one
side of the equation. Adaptive explainations are set up to explain how
and/or why something happened. That means you have s starting point
and an end point and are trying to explain the transition.
You can certainly set up a hypothetical starting point and then
attempt to show how it could logically follow along a course fitting
the idea to get to the modern condition, but that doesn't give
anything in the original idea's favor other than logical consistency
for that point. It does not make the original point more parsimonious,
and certainly doesn't lend it any support in a way that could be
construed as evidence. Its still speculation relying on credulity of
the reader for convincing rather than the strength of the theory and
the evidence on its own.
In addition, you say:
"As the earliest bipeds lived at least 6mya and we know nothing about
the possible swimming abilities of any hominid apart from the fact
that we are, today, the strongest of all the primates it is logical to
seperate them, I think"
This is not logical. It is again speculation that you are relying on
credulity for support. Much better to say that in your theory the two
aren't required to be together. You cannot say with any strength of
evidence if they were or weren't coincidental.
> > It's important for us to understand the lack of unity in the
> > hypothesis, because you (& Marc, & Pauline) tend to introduce
> > fragments of evidence piecemeal into the debate, & it if it isn't
> > clear which aquatic evolutionary event the evidence you proffer
> > relates to, it becomes difficult to understand your overall position.
>
> It is rather naive, I think, to expect any such "unity." Is there any
> unity in the non-aquatic theories? Having said that I'd argue that
> there is still probably more agreement within those that support the
> AAH than those who do not. For example we have about dozen different
> non-aquatic ideas on the origin of bipedality whereas all the
> different proponents of aome form of AAH agree that wading was
> probably the major factor.
It is not naive to expect such unity. It is the basis of having a
"theory". And you are correct, the "non-aquatic" theories that you and
Pauline refer to (and Marc dismisses) have little unity. However, this
is *because they are not theories*. They are straw men, and to claim
that your straw men don't have X so neither do you is to argue against
your own claims. You looked at the theories of bipedalism. You know
damn well that there is one of those "non-aquatic" theory that even by
your own reckoning was equivocal to your idea. It also happens to be
the same one that seems logically consistent and reasonable to me (and
I went to great lengths on the AAT list to use that speculative idea
(note, I did not call it a "theory" as I don't pretend to have
examined it close enough to try and build a theory) as a comparison to
another fringe idea to show equivolency of speculation and the
uselessness of credulity as the basis of evidence).
Acting as if multiple opinions invalidates all other ideas is as
closeminded as me stating that the multiple opinions in the AAT/AAH
crowd invalidates yours, right?
> I cannot speak for the others but for me it is pretty clear that
> humans are physically different from other apes in ways that can be
> explained some kind of adaptation to movement through water. That is
> the starting point upon which a detailed model has to be built and, of
> course, argued over. But that fundemental point is one you steadfastly
> refuse to accept, even as a possibility. It seems to me that
> aquasceptics have dug themselves into such a staunchly ant-AAH trench
> that they cannot now even admit the most absurdly mild of
> possibilities - in your case, even that our ancestors lived closer to
> water than ape ancestors did. This is, in a way, understandable. You
> clearly realise that admitting anything, on this slippery slope, would
> be tantamount to an admission that the AAH was actually right all
> along. Because if we lived by water more than chimps then, logically,
> we must have moved through it more too. If we moved through it more,
> then - through the laws of natural selection - clearly we'd have
> become more adapted to it too. All you'd be left with then is pathetic
> arguments about the 'degree' of aquaticism - claiming that these
> aquatic pressures would have been so slight as to have made no
> difference at all - an impossible position to hold.
Straw men again, Algis? I would have to label myself an "aquaskeptic".
Have you ever seen me refuse to admit possibilities? Or more
specifically, refuse to admit particular pieces of data? I have no
problem with human ancestors living near water, exploiting water
resources, or even that some pieces of evidence could be used to claim
a semi-aquatic past. What I *do* have a problem with is the misuse of
evidence as independent points of data when other points of data
contradict, discredit, or even at the most basic level make the data
equivocal. I *do* have a problem with the idea of human ancestors as
having physiologically adapated to extensive time in the water because
I simply do not see any logical consistency and credibility of
evidence to see physical adaptation to living in a water environment.
What I *do* have a problem with is the leap of logic from using water
resources, and their importance in the evolution of the human clade,
to the claim of physical adaptation to the water. What I *do* have a
problem with is the intellectual dishonesty of Marc, and his reuse of
information shown to be unreliable, incorrect, or equivocal, and its
use as the roseta stone of evolutionary biology. What I *do* have a
problem with is the intellectual dishonesty of Marc, and is explicit
refusal to admit he has been told something before, and to go out of
his way to force others to redo the same refutation/discrediting of
some particular point, such that people eventually tire of having to
redo the same typing over and over and over because every single time
he makes X claim and the same points are brought up again and again,
he claims to know nothing about them. What I *do* have a problem with
is you and Pauline continually referring to a straw man of "savanna
theory" so that you can dismiss it out of hand and sit back and bask
in the supposed self-evidence of the aquatic idea based on relative
credulity, even after that point has been brought to your attention
*multiple times*. I also have a problem with you and Pauline both
refusing to ever make a peep on any thread (either here or in AAT
group) that contradicts Marc, no matter how far off the deepend he is
on a particular issue, no matter how much he *lies* about something
and has the evidence that has has throw right back in his face, and
then every time someone posts some inane anectdote, you chime in with
"interesting! that sure seems to support aat! what do you think,
marc?".
Yes, I realize both of you haven't spent much time in AAT group in the
past year posting anyway, but when you both were posting daily on many
or even most topics, you scrupulously avoided contradicting Marc, even
when he was being obviously intellectually dishonest.
You state:
"You clearly realise that admitting anything, on this slippery slope,
would be tantamount to an admission that the AAH was actually right
all along."
Now, can you really claim you are being intellectually honest? Do you
really intend to state that if someone says, "Yes, a reduction in hair
could produce a minor and *insignificant* reduction in drag when in
the water." That they are admitting that AAH is "actually right all
along"?
> > So - bipedalism evolved as a response to wading in 1 evolutionary
> > event, & hairlessness / swimming / diving evolved in another putative
> > event. It takes a hybridisation to bring these 2 together, with
> > subsequent refining of the latter suite of characteristics in Homo. As
> > best as I can tell...
>
> No it doesn't need the hybridisation event. AFAIK I'm in a minority of
> one on that idea. The basic model is simple enough: Wading led to
> bipedalism and from the radiation that followed several hominids lived
> contemporaneously. Any number of those could have possibly started
> evolving in a Homo-like direction through swimming and diving. And
> according to some AAH models (e.g. Elaine's own ideas I think) these
> water-side living hominids could then have moved away from the water
> to become purely terrestrial. My own varient is that two such aquatic
> hominids interbred causing the Homo sapiens speciation and that the
> water-side living never really stopped. I'd argue that human ancestors
> were less aquatic than some of the other models but that it went on
> for longer - in fact never really stopped.
It is a just-so story, Algis. Maybe its correct, it could be after
all. But it is a just-so story (you set up the premise and devise a
manner that it could have proceeded from that premise to the known
present), not one based on physical evidence. Now, there are lots of
just-so ideas in paleoanthropology (how could there not be with so
little evidence?), but that doesn't make your's any better than those.
What is the unequivocal evidence supporting adaptation to a water
environment?Exploiting the environment is not good enough, we
obviously do and did do that. Positing a hypothesis and show how it
could happen is not good enough, there are hundreds of those. Showing
evidence that is equivocal with other ideas is not good enough, if the
evidence works as well with another idea(s), why pick yours over
those?
I have no problem with creating a hypothesis like you have done. I do
have a problem with you supporting it completely with just-so stories,
equivocal evidence, and appeals to credulity and then expecting for
people to support it as self-evident. Its perfectly fine to create a
hypothesis that you believe is correct, or more correct than others.
It is not perfectly fine to be so dismissive of anything or anyone
that doesn't agree, and those that do not see it as credulous just
because you do, nor to act as if someone that won't agree with you is
close-minded. Don't get me wrong, its just as obvious that many of the
people you argue with here have the same fault at times or even all
the time for some of them, but that doesn't excuse you doing the same.
> > Hardy envisaged the aquatic ape theory as a sweeping scenario which
> > would capture & explain all the odd features of human morphology in 1
> > fell swoop. This was at a time over 40 years ago when the number of
> > hominid fossils & level of data surrounding them was small enough to
> > possibly sustain such a view.
>
> Did he? Did he tell you that or did you read it somewhere? I was
> speaking with his son just before I left England and that is not the
> impression he gave me. Still, you know best.
Does it really matter what hardy believed? This is for both of you.
Just let it go. Ideas presented in a non-professional magazine by a
non-specialist 40 years ago aren't so important in an of themselves
they should be used to detract from an idea someone else has that is
similar or even inspired by the original.
> Hardy had made an observation (sc fat in aquatic mammals) and made the
> analogy with humans after reading about sc fat in humans. He realised
> that the theory was controversial so kept it 'in the dark' for thirty
> years before going public with it. He was, I feel, a rather more
> modest than you portray him to be.
He also believe in ESP, didn't he? =P Just another reason to keep him
out of this entirely. He's dead, he didn't spend his life creating or
defending an aah/aat theory, so why not keep it to those that have?
> Remember he only posed the question "Was Man more aquatic int he
> past?" More aquatic, note. The press knee-jerk reaction was to laugh
> at the idea and assume he was talking about dolphins and mermaids.
> Unfortunately, it seems that most PAs are still stuck in that
> knee-jerk first impression even today.
No, they aren't. Most are incredulous because they have been fed on
other ideas they whole career, and when they see the contradictions
and level of evidence being used by the most vocal aat/aah adherents
they lump them together with the ufo people. It isn't a knee-jerk
reaction, its a delayed reaction informed by the fallacies that some
aah/aat adherents refuse to abandon.
When it gets boiled down to aat/aah being an idea of exploitation of
marine or riverine resources, you get a better response. When it comes
to claiming a physical adaptation to those resources or manner of
living, there is more skepticism, but people listen. When you fall
back on the same tired stuff mentioned before, dismiss honest
incredulity, or depend on just-so stories to support the position,
then they run screaming for the hills.
There are a lot of problems with academia, and one of those is the
resistance to new ideas. So even when someone has a "Great Idea" there
is resistance. But when someone refuses to critically examine their
own position, or the position of those that lend them some support
just to maintain that support, then you reap what you sew in terms of
credibility.
> All he was trying to do was to stimulate a debate and to encourage
> scientists to test the theory. The response was appauling. Almost
> nothing was done and the only words that were said were ridicule.
How exactly is the "theory" tested? If it was testable there would be
a lot less problems with the various AAH/AAT scenarios. How do we test
your scenario, Algis? Is there a way? Is there any piece of evidence
we might find that will vindicate your scenario? Or are we forced to
deal with just-so stories based on credulity and the fact that you can
wiggle the hypothesis around so that we are left with only equivocal
evidence regarding it?
> > You'll not be surprised that I view your hypothesis as firstly an
> > acceptance that this vision of a single over-arching aquatic
> > explanation has failed, and secondly as a construct developed in
> > response to a desire to maintain an aquatic ape hypothesis after
> > Hardy's vision has failed.
>
> It's not that it failed. Hardy never had a model as such. He made no
> predictions, had the barest timescale and offered no evidence other
> than human anatomy analogies with aquatics. He was merely asking a
> question so how could it have failed? The failure, if there was one,
> must lie with the paleoanthropologists of the 1960s who simply ignored
> it completely rather than having an ounce of proper scientific
> curiosity about the idea.
Now this is ridiculous. If the aquatic ideas are so important and
convincing, the failure was in the adherents to provide real evidence
in support of it, and to argue with what evidence they do have
honestly. Do you realize that many people working in physical
anthropology haven't even heard of aat type hypotheses? That's right.
Ask many, and they don't know what they hell you are talking about.
Hell, whenever someone even tries to give the benefit of the doubt
they get run off by the bullshit. Please explain why someone can spout
off an idea in an non-academic setting, an opinion piece, and it is
now the responsibility of those in the field to waste their time and
resources in investigating it?
The idea is not so self-evident that it has drawn people interested in
working on it academically. Most that have even had the thought of
doing so get so disgusted by some particular supporters and the
standard of evidence that they go on to other things. That is the
failure of the idea. That is the failure of those that support it (or,
more importantly, those that have supported it for decades), not the
failure of paleoanthropologists.
> Like Elaine Morgan, when I heard about the idea, I first thought 'yes,
> there's something in this obviously' and then, when I realised that
> the textbooks didn't even mention it as a possibility - 'so, what's
> wrong with it?'
>
> Because I had the benefit of Elaine's books and the chance to read the
> debates on this forum I could see both sides of the argument. I could
> see the strengths - like we are dependent on water, we can swim better
> than apes and infants do seem relatively comfortable in water; and the
> weaknesses - we're not really much like true aquatics, semi-aquatic
> mammals are not really like us and although we are mainly fresh water
> adapted we do have odd traits that indicate a marine link too. I made
> it my goal to come up with a version of the AAH that kind of fitted in
> the middle somewhere and made sense to both sides. (Optimistic, I
> know! :-))
Why not try and do real science by investigating specific problems and
searching for the best answer the evidence supports rather than
starting with a general theory and trying to build into that theory?
> > Crucial to the specifics of your particular hypothesis is the supposed
> > hybridisation event. To my knowledge, there is no paleontological
> > precedent, nor any theory of genetics or speciation amongst
> > multicellular organisms, which could accomodate an event as unlikely
> > as you describe.
>
> The hybridisation event is an explanation of the chromosome number
> change and, simultaneously, our speciation. It also, for me, answers a
> few contradictions about the AAH - like the fresh water/salt water
> ones.
Hybridisation of populations does not explain the differences in
chomosome number in humans and the great apes. The fusion in the human
clade is an interesting question, but your scenario can't explain it.
Your hybridization event and everything that could be construed to
support it is speculation. You're entitled to your speculations, but I
would suggest you don't marry another broad speculation into the
already broad one of AAT/AAH.
> > My view on this is simply: if you have to
> > invent a unique & unprecedented biological occurence to sustain your
> > worldview, your worldview, in my opinion, simply can't be sustained.
>
> The hybridisation event is not necessary in the AAH but I have yet to
> read a more convincing model for chromosome number change. And, Ross,
> we do have different numbers of chromosomes than the other great apes.
> The AAH makes more sense to me with hybridisation in the model, that's
> all I can say at the moment.
The chromosome change was a fusion of two chromosomes into one.
Hybridisation of populations (gene flow) does not explain this in any
way shape or form. The event occurred and spread among a population.
No if and or buts about it Hell, a hybridisation of two populations
(one with the original 48 and one with 46) just gives another chance
for selection and/or genetic drift to grind the 46 chromosome types
out of the population, making it more difficult for the change to
spread species wide if it has to open up the potential breeding
population and drop the frequency of those with 46.
> > > > Final question - when did the hominids become savannah-adapted?
> > >
> > > Never.
> >
> > Yes well... I had hoped you could display more objectivity than that,
> > but I'm afraid that response just sums up the direction of this whole
> > debate. It's going nowhere.
>
> There are aquasceptics that would dismiss the savannah adaptation idea
> as strongly as I do.
Keep away from the strawman of savanna if you want others to stay away
from the strawman of dolphins and mermaids.
> > Algis, you may have better manners than Marc, but your hypothesis of
> > hominid evolution is no better, & the chances of you being ever able
> > to recognise it are no better either. So for now, I'm giving up on
> > exercises in futility...
>
> You're entitled to your opinion, of course. In return may I just say
> that for a moment I thought you were an objective-minded poster to
> this forum but you've rather disappointed me with your rigid
> aquascepticism. You are, I think, about as objective as Clarke and
> Love although I would grant that you do argue more convincingly than
> they do.
>
> Algis Kuliukas
Objective people are skeptical by nature, otherwise they would latch
on to the first thing that strikes their fancy and subjectively judge
everything else from that position
*cough*likemanyaatsupporters*cough*. Maintaining objectivity means you
maintain skepticism of *everything* and it is up to those that claim
to support one subjective interpretation to convince them.
He asked you questions, and didn't like your answers, and addressed
them, didn't dismiss him. That makes him (at least in this exchange)
objective.
CDK
Marc Verhaegen
news:fc59222d.03050...@posting.google.com...
seems to be terribly frustrated by his inability to find 1 argument against
our scenario:
In 1960 Alister Hardy ("Was Man more aquatic in the past?" New Scientist)
described how a sea-side lifestyle - wading, swimming, collecting edible
shells, turtles, crabs, coconuts, seaweeds etc. - could explain many
typically human features that are absent in our nearest relatives the
chimps, and that cannot be explained by savanna scenarios: very large
brain, greater breathing control, well-developed vocality, very dextrous
hands, stone tool use, reduction of climbing skills, reduction of fur,
thicker subcutaneous fat tissues, very long legs, more linear body build,
high needs of iodine, sodium & poly-unsaturated fatty acids etc.
Hardy was only wrong at the time in thinking this seaside phase happened
more than 10 Ma. Early Pleistocene Homo fossils or tools have been found in
Israel, Algeria, E.Africa, Georgia, Java. When sea levels dropped during the
Ice Ages, H.ergaster-erectus followed the Mediterranean & Indian Ocean
coasts. Although most Pleistocene coasts are some 100 m below the present
sea level (IOW the fossil & archeological record often shows the inland Homo
populations that entered the continents along the rivers) Homo remains have
frequently been found amid shells, corals, barnacles etc., in European,
African & Asian coasts, throughout the Pleistocene (eg, Mojokerto, Terra
Amata, Table Bay, Eritrea), and even on islands that could only be reached
oversea (Flores 0.8 Ma).
Marc Verhaegen
http://www.onelist.com/community/AAT
http://allserv.rug.ac.be/~mvaneech/Verhaegen.html
Charles
Ross Macfarlane wrote:
snip to hybrid stuff>>
> Algis, it's my suspicion that your hypothesis began as an attempt to
> create a hybrid between contradictory lines of evidence, and you
> somehow twisted this philosophical construct, in your mind, into an
> actual hybridisation event. My view on this is simply: if you have to
> invent a unique & unprecedented biological occurence to sustain your
> worldview, your worldview, in my opinion, simply can't be sustained.
> >
but hominids apparently have experienced a hybridization with Tre2. This is a repost that I put out there the day
it was published in Science News:
Search only in sci.anthropology.paleo Search all groups Search the Web
Groups search result 1 for hybrid charles group:sci.anthropology.paleo
group:sci.anthropology.paleo
Search Result 1
From: Charles (lm...@mindspring.com)
Subject: Tre2 as a hybrid
This is the only article in this thread
View: Original Format
Newsgroups: sci.anthropology.paleo
Date: 2003-02-25 14:33:45 PST
"Analysis of genetic data from a variety of mammals show that this gene,
called Tre2, occurs only in apes and people...," "...Tre2 represents a
hybrid, or so-called chimeric version, of two genes that fused together,
Paulding and his coworkers assert...." "... The DNA sequence of roughly
half of Tre2 closely corresponds to an evolutionarily ancient gene still
possessed by many species of mammals...." "Fusion of the two genes must
have occurred after the arrival of a common ancestor of apes and humans,
between 21 million and 33 million years ago, the scientists theorize."
"[affects only the testes; may implicate] Tre2 in sperm function, it
will support the possibility that the gene's emergence created
reproductive barriers between ancient creatures that did and did not
have it."
From Science News, Vol. 163, No. 8, Feb. 22, 2003, p. 115.
"_Evolution's DNA Fusion: Hybrid gene forms clue to human, ape origins_
A gene of mixed evolutionary pedigree may have transformed mammalian
reproduction, leading to the evolution of apes and humans.
References: Paulding, C.A., M. Ruvolo, and D.A. Haber. In press. The
Tre2 (USP6) oncogene is a hominoid-specific gene. Proceedings of the
National
Academy of Sciences. Abstract available at
http://dx.doi.org/10.1073/pnas.0437015100.
Sources:
Pascal Gagneux
University of California, San Diego
Department of Chemistry and Biochemistry
9500 Gilman Drive
MC 0332
La Jolla, CA 92093-0332
Daniel A. Haber
Massachusetts General Hospital Cancer Center
Harvard Medical School
Charlestown, MA 02129
Charles A. Paulding
Massachusetts General Hospital Cancer Center
Harvard Medical School
Charlestown, MA 02129
Maryellen Ruvolo
Department of Anthropology
Harvard University
Cambridge, MA 02138
Abazagaroth
/yawn
You are intellectually dishonest and a liar, and as I told you before,
I will no longer bother trying to discuss anything with you.
Ross Macfarlane
> Ross Macfarlane wrote:
> snip to hybrid stuff>>
>
> > Algis, it's my suspicion that your hypothesis began as an attempt to
> > create a hybrid between contradictory lines of evidence, and you
> > somehow twisted this philosophical construct, in your mind, into an
> > actual hybridisation event. My view on this is simply: if you have to
> > invent a unique & unprecedented biological occurence to sustain your
> > worldview, your worldview, in my opinion, simply can't be sustained.
> > >
>
> but hominids apparently have experienced a hybridization with Tre2. This is a repost that I put out there the day
> it was published in Science News:
>
> called Tre2, occurs only in apes and people...," "...Tre2 represents a
> hybrid, or so-called chimeric version, of two genes that fused together,
> Paulding and his coworkers assert...." "... The DNA sequence of roughly
> half of Tre2 closely corresponds to an evolutionarily ancient gene still
> possessed by many species of mammals...." "Fusion of the two genes must
> have occurred after the arrival of a common ancestor of apes and humans,
> between 21 million and 33 million years ago, the scientists theorize."
> "[affects only the testes; may implicate] Tre2 in sperm function, it
> will support the possibility that the gene's emergence created
> reproductive barriers between ancient creatures that did and did not
> have it."
>
> From Science News, Vol. 163, No. 8, Feb. 22, 2003, p. 115.
> "_Evolution's DNA Fusion: Hybrid gene forms clue to human, ape origins_
> A gene of mixed evolutionary pedigree may have transformed mammalian
> reproduction, leading to the evolution of apes and humans.
>
> References: Paulding, C.A., M. Ruvolo, and D.A. Haber. In press. The
> Tre2 (USP6) oncogene is a hominoid-specific gene. Proceedings of the
> National
Look, I'm not an expert on genetics but I don't think the fusion of 2
chromosomes is the same as the fusion of 2 species, or 2 subspecies
with apparently very different niches. Nor is there any evidence to
link this with supposed aquatic evolutionary phases.
Ross Macfarlane
Jim McGinn
> Think about the AAT list. Think about how many times I pointed out
> that there is no "savanna theory", that the concept being attacked
> there was just a straw man (both in the interpretation of what savanna
> meant and in the idea there is some larger "theory" tied to it that is
> widely accepted), and that there was no "standard PA" that kept being
> attacked there. Paleoanthropology is a specialized subfield of
> physical anthropology, and the fact that a myriad of intro phys anth
> classes regurgitate the same stuff from 20-50 years ago because both
> the professors teaching those classes and those that wrote the intro
> books are not paleoanthropologists does not mean there is any
> "standard PA".
Well, I don't know. It's one thing to say that the AAT dimwits
have created a false representation (strawman) of their
opposition's position. It's quite another, however, to suggest
that standard PA does not, like the AAT dimwits, also suffer
from an inability to see beyond their beliefs. AAT dimwits
think water answers everything, conventional dimwits think some
kind of tool-using/making hunter-gathering ape answers everything.
Different dimwits, same problem: the inability to see beyond
their beliefs.
<snip>
Ross Macfarlane
...
> > Remember he only posed the question "Was Man more aquatic int he
> > past?" More aquatic, note. The press knee-jerk reaction was to laugh
> > at the idea and assume he was talking about dolphins and mermaids.
> > Unfortunately, it seems that most PAs are still stuck in that
> > knee-jerk first impression even today.
>
> No, they aren't. Most are incredulous because they have been fed on
> other ideas they whole career, and when they see the contradictions
> and level of evidence being used by the most vocal aat/aah adherents
> they lump them together with the ufo people. It isn't a knee-jerk
> reaction, its a delayed reaction informed by the fallacies that some
> aah/aat adherents refuse to abandon.
>
> When it gets boiled down to aat/aah being an idea of exploitation of
> marine or riverine resources, you get a better response. When it comes
> to claiming a physical adaptation to those resources or manner of
> living, there is more skepticism, but people listen. When you fall
> back on the same tired stuff mentioned before, dismiss honest
> incredulity, or depend on just-so stories to support the position,
> then they run screaming for the hills.
>
it's scary. As described in an earlier post to Algis,I first appeared
on SAP I came prepared to believe, but after 1 day of seeing what
passed for an aquatic ape theory, & the quality of its supporters, I
was permanently cured.
>
> Objective people are skeptical by nature, otherwise they would latch
> on to the first thing that strikes their fancy and subjectively judge
> everything else from that position
> *cough*likemanyaatsupporters*cough*. Maintaining objectivity means you
> maintain skepticism of *everything* and it is up to those that claim
> to support one subjective interpretation to convince them.
>
> He asked you questions, and didn't like your answers, and addressed
> them, didn't dismiss him. That makes him (at least in this exchange)
> objective.
>
> CDK
Thank you sir. Very civil of you (at least in this exchange :-)...
Ross Macfarlane
Pauline M Ross
[... an awful lot of stuff...]
Goodness, what a diatribe. Do you feel better now?
There's too much arm-waving in there for me to attempt to quote and
respond, so I have snipped everything, but I will attempt to answer
the two major criticisms you accuse me of.
1) The 'savanna theory' is a strawman.
I'm quite happy to accept that there is not and never was a grand
overarching Savanna Theory. But the 'savanna as major influence on
human evolution' is *not* a strawman. It has influenced
paleoanthropology, root and branch, for decades and it *still does*.
Of course there have been adjustments over the years, notably
bipedalism has been pushed back into the trees and the definition of
'savanna' has expanded, but the original idea of a hot, dry
environment still informs a great deal of PA thinking. I have quoted
one professional lamenting that researchers are still fixated on a
Serengeti-type environment, and public-consumption human evolution
still peddles that line - witness the recent BBC series 'Walking With
Cavemen', which showed our ancestors trailing prey across what can
only be described as desert, and that included the likes of Chris
Stringer and Leslie Aiello in the credits.
So let's not pretend that the 'savanna' business is history. A lot of
PAs know that it is dead, but a lot don't, and you admit yourself that
it is still taught, so it is hardly likely to disappear anytime soon,
is it?
As for talking about 'standard PA' or 'conventional PA', how else
would you collectively describe professionals who generally follow the
current thinking in their field (with individual variations, of
course)? It's not intended as an insult, just shorthand for use in an
informal forum, and nobody supposes that there is a 'Standard PA
Theory' any more than there is a 'Savanna Theory', or a single
'Aquatic Ape Theory' for that matter.
Recently I've switched to using Algis's 'aquasceptic' as my preferred
term for 'the others' - seems more descriptive.
2) Other AATers should intervene in Marc's discussions
You said: "...you scrupulously avoided contradicting Marc, even
when he was being obviously intellectually dishonest." You also used
the word "lies". Well now, I don't think he lies at all, I think he
believes what he says. And where I spot him saying something which I
think is totally wrong, I *do* intervene.
But mostly, you know, Marc's threads are either interminably long or
ad hominem. The ad hominem I ignore, and life's just too short to read
every word of the long stuff, especially when a lot of it is
repetition. So I just don't see a lot of what is being said. And I'm
not sure why it should be my job to supervise Marc anyway.
But I do disagree violently with Marc's approach - I think all the ad
hominem stuff is counter-productive and brings the whole AAH into
disrepute (and your post basically confirms that). And I've told him
what I think many times, but I don't suppose he's going to change now,
do you? Which makes me wonder why some of the regulars here continue
to go round and round with him ... very strange.
--
Pauline Ross
Richard Wagler
Pauline M Ross wrote:
> On 8 May 2003 12:19:29 -0700, dkr...@yahoo.com (Abazagaroth) wrote:
>
> [... an awful lot of stuff...]
>
> Goodness, what a diatribe. Do you feel better now?
>
> There's too much arm-waving in there for me to attempt to quote and
> respond, so I have snipped everything, but I will attempt to answer
> the two major criticisms you accuse me of.
>
> 1) The 'savanna theory' is a strawman.
>
> I'm quite happy to accept that there is not and never was a grand
> overarching Savanna Theory. But the 'savanna as major influence on
> human evolution' is *not* a strawman. It has influenced
> paleoanthropology, root and branch, for decades and it *still does*.
And why shouldn't it? A huge mass of evidence says early
hominids lived in svannah environments (propoerly defined).
The whole problem is that Morgan et al have taken the Dartian
position as some kind of orthodoxy and with the changes in
the picture that research beginning 40 years ago mandated
have tried to use this to promote the ridiculous idea that early
hominids never lived in savannah environments of any description
whatsoever. Dart was a perpetual outsider not a main pillar
of some orthodoxy. Read what PAs were actually saying and
forget 'popular' representations. The standard AAT critique of
PA is absolute junk - a classic definition of a strawman.
>
>
> Of course there have been adjustments over the years, notably
> bipedalism has been pushed back into the trees and the definition of
> 'savanna' has expanded,
has it?
> but the original idea of a hot, dry
> environment still informs a great deal of PA thinking. I have quoted
> one professional lamenting that researchers are still fixated on a
> Serengeti-type environment,
I read that article too. Not a bad piece. Too bad you only
take out of it what you want. Still there were very dry areas
in Pliocene Africa - Kanapoi comes to mind - and hominid
fossils have been found there. In any event the scavenging
studies done in dry savannahs kind of confirm the point that
a living was avaiable to any hominid who might have been
in these sorts of places were they of a mind to scavenge.
> and public-consumption human evolution
> still peddles that line - witness the recent BBC series 'Walking With
> Cavemen', which showed our ancestors trailing prey across what can
> only be described as desert,
If you remember these were erectus. The Acheulian archaeological
record shows that these folks inhabited arid areas along with
nearly everyplace else. The scenes involving a'piths were not
like this.
> and that included the likes of Chris
> Stringer and Leslie Aiello in the credits.
So? What falsehood do you think was prmulgated
by this program?
>
>
> So let's not pretend that the 'savanna' business is history. A lot of
> PAs know that it is dead, but a lot don't, and you admit yourself that
> it is still taught, so it is hardly likely to disappear anytime soon,
> is it?
Define 'savannah theory'
>
>
> As for talking about 'standard PA' or 'conventional PA', how else
> would you collectively describe professionals who generally follow the
> current thinking in their field (with individual variations, of
> course)? It's not intended as an insult, just shorthand for use in an
> informal forum, and nobody supposes that there is a 'Standard PA
> Theory' any more than there is a 'Savanna Theory', or a single
> 'Aquatic Ape Theory' for that matter.
>
> Recently I've switched to using Algis's 'aquasceptic' as my preferred
> term for 'the others' - seems more descriptive.
>
> 2) Other AATers should intervene in Marc's discussions
>
> You said: "...you scrupulously avoided contradicting Marc, even
> when he was being obviously intellectually dishonest." You also used
> the word "lies". Well now, I don't think he lies at all, I think he
> believes what he says. And where I spot him saying something which I
> think is totally wrong, I *do* intervene.
Where? Do you, for example, simply accept Marc's assertion
that proboscis monkeys are the most bipedal of monkeys
even though he is completely unable to back this up? Have
you ever checked any of Marc's references? Or do you
simply accept his assurance that they are relevant and say what he
says they do? I have cheecked some of his references and
you should not accept any of them at face value.
>
>
> But mostly, you know, Marc's threads are either interminably long or
> ad hominem. The ad hominem I ignore, and life's just too short to read
> every word of the long stuff, especially when a lot of it is
> repetition. So I just don't see a lot of what is being said. And I'm
> not sure why it should be my job to supervise Marc anyway.
Because he is doing an enormous amount of damage to
the project you are supporting. Attempting to get a hearing
in academic circles for aquatic hypotheses. For us dry apers
if Marc didn't exist we'd have to invent him. The man is a
godsend.
>
>
> But I do disagree violently with Marc's approach - I think all the ad
> hominem stuff is counter-productive and brings the whole AAH into
> disrepute (and your post basically confirms that). And I've told him
> what I think many times, but I don't suppose he's going to change now,
> do you? Which makes me wonder why some of the regulars here continue
> to go round and round with him ... very strange.
Moth to a flame......the sublime awfulness of his cracked
logic and surreal non sequiturs is, at times, too much to resist....
Rick Wagler
Jim McGinn
> There's too much arm-waving in there for me to attempt to quote and
> respond, so I have snipped everything, but I will attempt to answer
> the two major criticisms you accuse me of.
>
> 1) The 'savanna theory' is a strawman.
>
> I'm quite happy to accept that there is not and never was a grand
> overarching Savanna Theory. But the 'savanna as major influence on
> human evolution' is *not* a strawman. It has influenced
> paleoanthropology, root and branch, for decades and it *still does*.
Yep.
>
> Of course there have been adjustments over the years, notably
> bipedalism has been pushed back into the trees and the definition of
> 'savanna' has expanded, but the original idea of a hot, dry
> environment still informs a great deal of PA thinking. I have quoted
> one professional lamenting that researchers are still fixated on a
> Serengeti-type environment, and public-consumption human evolution
> still peddles that line - witness the recent BBC series 'Walking With
> Cavemen', which showed our ancestors trailing prey across what can
> only be described as desert, and that included the likes of Chris
> Stringer and Leslie Aiello in the credits.
Yes, they only consider evidence that fits their hunter-gatherer
model--talk about intellectual dishonesty.
By focussing on Marc it takes attention off the fact that they really
have no hypothesis at all.
Jim
Jim McGinn
> > When it gets boiled down to aat/aah being an idea of exploitation of
> > marine or riverine resources, you get a better response. When it comes
> > to claiming a physical adaptation to those resources or manner of
> > living, there is more skepticism, but people listen. When you fall
> > back on the same tired stuff mentioned before, dismiss honest
> > incredulity, or depend on just-so stories to support the position,
> > then they run screaming for the hills.
> >
> Mate, that's such an accurate description of my experience with AAH
> it's scary.
It's also an accurate description of my experience
with conventional thinking.
Jim
Pauline M Ross
wrote:
>>[Pauline] I'm quite happy to accept that there is not and never was a grand
>> overarching Savanna Theory. But the 'savanna as major influence on
>> human evolution' is *not* a strawman. It has influenced
>> paleoanthropology, root and branch, for decades and it *still does*.
>
>[Rick] And why shouldn't it? A huge mass of evidence says early
>hominids lived in svannah environments (propoerly defined).
Would you define savannah for me, Rick? It's difficult to discuss a
concept without knowing what you mean by it.
>The whole problem is that Morgan et al have taken the Dartian
>position as some kind of orthodoxy [...] The standard AAT critique of
>PA is absolute junk - a classic definition of a strawman.
Now you're doing exactly what David was complaining of :-) What
exactly is the "standard AAT critique of PA"?
>>[Pauline] Of course there have been adjustments over the years, notably
>> bipedalism has been pushed back into the trees and the definition of
>> 'savanna' has expanded,
>
>[Rick] has it?
Well, it seems to me that it has. I've quoted my preferred definition
before (tropical grassland, scattered trees, dry season - from a very
reputable source), but various people have defined it to include
extensive trees and a lot of water.
>
>>[Pauline] but the original idea of a hot, dry
>> environment still informs a great deal of PA thinking. I have quoted
>> one professional lamenting that researchers are still fixated on a
>> Serengeti-type environment,
>
>[Rick] I read that article too. Not a bad piece. Too bad you only
>take out of it what you want.
Well, I take out of it lots of things, but Tappen's comments about the
Serengeti are the only ones I have had occasion to quote to date.
>Still there were very dry areas
>in Pliocene Africa - Kanapoi comes to mind - and hominid
>fossils have been found there. In any event the scavenging
>studies done in dry savannahs kind of confirm the point that
>a living was avaiable to any hominid who might have been
>in these sorts of places were they of a mind to scavenge.
Well, Tappen's findings and quotes from other studies kind of indicate
that it would have been more a supplement than a living (although more
likely in dry areas). But her study was fairly limited.
>
>>[Pauline] and public-consumption human evolution
>> still peddles that line - witness the recent BBC series 'Walking With
>> Cavemen', which showed our ancestors trailing prey across what can
>> only be described as desert,
>
>[Rick] If you remember these were erectus.
Ergaster, actually.
> The Acheulian archaeological
>record shows that these folks inhabited arid areas along with
>nearly everyplace else. The scenes involving a'piths were not
>like this.
No, the a'piths were shown in grassland with scattered acacia trees,
or in denser woodland along rivers. Most of the rest were in dry, open
areas, in some cases verging on desert. The Asian erectus were in a
wetter environment, and the Neandethals were in snow, of course.
>
>>[Pauline] and that included the likes of Chris
>> Stringer and Leslie Aiello in the credits.
>
>[Rick] So? What falsehood do you think was prmulgated
>by this program?
We are not adapted for and did not evolve in dry, near-desert
conditions. In my opinion. Bipedalism in particular did not evolve in
a dry, open habitat, and it is misleading to suggest that it did.
I have to say, though, that the book accompanying the series (by John
Lynch and Louise Barrett) is much more balanced.
>Define 'savannah theory'
Pass.
>>[Pauline] And where I spot him saying something which I
>> think is totally wrong, I *do* intervene.
>
>[Rick] Where? Do you, for example, simply accept Marc's assertion
>that proboscis monkeys are the most bipedal of monkeys
>even though he is completely unable to back this up? Have
>you ever checked any of Marc's references? Or do you
>simply accept his assurance that they are relevant and say what he
>says they do? I have cheecked some of his references and
>you should not accept any of them at face value.
Well, I don't accept anything *anyone* says here at face value. Almost
all the regulars on sap have an axe to grind, so everyone is quoting
selectively, and pointing out evidence that supports their case, and
not mentioning anything that doesn't.
And I don't regard that as intellectual dishonesty *if* whenever
anyone finds apparently contradictory evidence, they mull it over and
research it and work out for themselves what it actually means. I do
that, and I know Algis does, and Mario, and I expect Marc does too,
but nobody sees it so you assume we are all just working on blind
faith. Not so.
As to the proboscis monkeys, I have no idea whether Marc is right, and
no immediate way to find out. Since I don't have an informed comment
to make, I say nothing. OK?
--
Pauline Ross
Algis Kuliukas
First of all thanks for your time in posting this. I appreciate your
feedback.
> Hypotheses built on hypotheses built on more hypotheses lend little to
> credibility, and only end up appealing to those credulous to the idea
> in the first place (and only incite the flames of those incredulous to
> the idea to begin with).
> This was the point of Langdon's JHE paper 6 years ago. These aquatic
> theories are theories of everything and nothing. They try to explain
> everything, and whenever any part is shown to be incorrect, equivocal,
> or even just unlikely, there is the cry that this doesn't matter,
> because its only a "minor" part of the theory in the first place.
I agree that 'these aquatic theories' have been rather disparate:
Hardy made no real predictions; Morgan that the aquatic 'phase'
happenned about 6mya since the split with Pan, Verhaegen that all apes
were quasi-aquatic and then Homo became more so; Crawford etc that
hominids simply lived by water and became dependent on aquatic food
chain. That was one of my goals in trying to bring them together into
a single model.
Aren't all hypotheses about human evolution built upon hypothesis and
so ad infinitum? And will you accept that there is also some factual
basis to the AAH too? For example: Apes are better at moving through
trees than humans, we are better at moving through water than them. Is
it not logical that if that were true, and I trust you wouldn't argue
against it, that there should be some evolutionary explanation for
that? And that such an explanation is likely to be, merely, (surprise,
surprise) that our ancestors lived by water more than their's did?
> This is why people get so frustrated with Marc, as he has this down
> pat. Whenever someone points out a single problem, he turns the
> problem back out onto the overarching theory in an attempt to minimize
> the importance of the original point, and then claim "no one has
> presented 1 argument against" his scenario (because in his mind the
> original point is no longer an "argument against" since he has
> deflected it back onto the overarching theory which is still
> supporting by all the other pieces of "evidence"). It doesn't matter
> if some, many, most, or even all of the points in support of the
> theory have been discredited or shown to be equivocal, since he
> refuses to stop using this - at best - illogical and naive method or -
> at worst - intellectually dishonest method.
I have shared your frustration with some of his tactics from time to
time. I am reluctant to criticise more than that because I respect his
enthusiasm. One thing I find very distasteful is the level of
arrogance and downright nastiness that this debate seems to generate.
It's not as if anyone *knows* what happenned. I know Marc is a guilty
of this as anyone but he must feel, sometimes, he is fighting off the
whole world on his own. I've had the pleasure of meeing Marc and found
him to be a charming, very intelligent and amazingly well-read man who
is honestly trying to push our understanding further. Sometimes he
gets too passionate but any enthusiastic person is guilty of that from
time to time.
> It is perfectly fine to have an umbrella theory. You're welcome to it.
> However, it is only as strong as its weakest point. It could still be
> correct, almost anything is possible, but you can't dismiss everything
> else while latching onto one point, and then use that single point as
> the bar of credulity of the theory.
> In addition, by recognizing your ideas as multiple hypotheses, you
> should be recognizing that the same is true of *every* larger idea in
> reconstructing human origins. Just like it is unfair to brand all
> aquatic based ideas based on one point of data or on the evaluation of
> one particular brand of aquaticism, the same is true for then
> "savanna" straw man that most of the aquatic crowd likes to attack.
Fine. I agree we need to stop using straw men arguments. As you say
later - that applies equally to 'we can't survive in arid savannah'
arguments as it does those 'humans lack traits of true aquatics'.
I think it's possible to find points of agreement and overlap between
savannah and AAH. Sweat cooling is a perfect example. I think it is
undeniably an advantage for any hominid on the savanna to be able to
keep cooler through sweating but it only makes sense if they could
also replenish the water lost regularly and reliably.
> Think about the AAT list. Think about how many times I pointed out
> that there is no "savanna theory", that the concept being attacked
> there was just a straw man (both in the interpretation of what savanna
> meant and in the idea there is some larger "theory" tied to it that is
> widely accepted), and that there was no "standard PA" that kept being
> attacked there. Paleoanthropology is a specialized subfield of
> physical anthropology, and the fact that a myriad of intro phys anth
> classes regurgitate the same stuff from 20-50 years ago because both
> the professors teaching those classes and those that wrote the intro
> books are not paleoanthropologists does not mean there is any
> "standard PA". Might as well do your academic research from an
> encylcopedia britanica if that is the definition of "standard".
Of course. Who could disagree with that?
> Now,
> what happened when I pointed this out? Aside from Marc posting some
> link to a news blurb written by a reporter (which only served to prove
> the point of the inappropriate straw man interpretation of the
> supposed "rival" savanna theory), several times you and Pauline and
> maybe one or two others responded that they understood, or that was
> interesting, that they didn't realize that, whatever. Then two days
> later all would revert to using the same snipes against "savanna
> theory" and "standard PA" that you claimed as inappropriate from the
> "aquasceptics" that sniped at the various AAT/AAH strawmen.
Point taken. I suppose I am guilty of this from time to time. All I
can say is that it's a product of frustration. You might have seen
some of the threads I've been involved in lately where every single
point is countered and not a single smidgen of a millimetre is ever
given. I've bent over backwards to try to find some middle ground but
there's never a yeilding.
Take the Sharp & Costill paper. I perhaps over-stated it at first by
claiming that it was good evidence for why apes might have lost their
body hair. Jason responded by saying as much so I retracted that and,
instead, argued that it was at least evidence in favour of humans
losing body hair to help their swimming. (I mean if it not possible to
even say that shaved men swimming 4% more efficiently is a piece of
evidence in favour of the AAH, what data could ever be used?) But no,
I couldn't have that either. Pauline came to my defence by arguing
that PAs often use far wider extrapolations that I did, but no, that
point had to be rejected too. It's this smug, self-righteousness that
gets my goat.
You have to admit that when it comes to the AAH, there seems to be
very few PAs prepared to defend any argument in favour of it and when
any of them (like Tobias) so much as hint of doing so they are
attacked. So, in an aquatic sense, there does seem to be a "standard
(i.e. anti AAH) PA."
> > Yes, that's right. The hypothesis is that moving through water was a
> > big factor in our evolution. Wading does not really require hair loss
> > to improve locomotor efficiency whereas swimming and diving do. As the
> > earliest bipeds lived at least 6mya and we know nothing about the
> > possible swimming abilities of any hominid apart from the fact that we
> > are, today, the strongest of all the primates it is logical to
> > seperate them, I think.
>
> Get rid of "require". There is no requiring of hair loss, for any
> reason.
Ok. Let me restate it as this: Wading does not really require hair
loss
to improve locomotor efficiency whereas there is data to indicate that
it may help swimming.
Sorry, I think you're just being pedantic and picky. Of course it's
speculation but do you seriously contest any of those points? I might
have said that 'the two aren't required together' - and have on
several ocassions before - but I was tired and this is only the sap
forum.
Here again, it's this patronising, ex cathedra tone coming through all
the time. Can't we just get to the issues and forget the pretence?
> > It is rather naive, I think, to expect any such "unity." Is there any
> > unity in the non-aquatic theories? Having said that I'd argue that
> > there is still probably more agreement within those that support the
> > AAH than those who do not. For example we have about dozen different
> > non-aquatic ideas on the origin of bipedality whereas all the
> > different proponents of aome form of AAH agree that wading was
> > probably the major factor.
>
> It is not naive to expect such unity. It is the basis of having a
> "theory". And you are correct, the "non-aquatic" theories that you and
> Pauline refer to (and Marc dismisses) have little unity. However, this
> is *because they are not theories*.
I always use 'H' not 'T'. Does that help?
> They are straw men, and to claim
> that your straw men don't have X so neither do you is to argue against
> your own claims. You looked at the theories of bipedalism. You know
> damn well that there is one of those "non-aquatic" theory that even by
> your own reckoning was equivocal to your idea. It also happens to be
> the same one that seems logically consistent and reasonable to me (and
> I went to great lengths on the AAT list to use that speculative idea
> (note, I did not call it a "theory" as I don't pretend to have
> examined it close enough to try and build a theory) as a comparison to
> another fringe idea to show equivolency of speculation and the
> uselessness of credulity as the basis of evidence).
Sorry, I don't get your drift.
> Acting as if multiple opinions invalidates all other ideas is as
> closeminded as me stating that the multiple opinions in the AAT/AAH
> crowd invalidates yours, right?
Not 'invalidates'. It's just that after 150 years you'd think there'd
be more of a concensus by now. The lack of such agreement implies to
me that something simple has been overlooked - something like wading
through water - you know, the one thing that gets apes to move
bipedally with any degree of certainty for as long as the condition is
maintained.
> > I cannot speak for the others but for me it is pretty clear that
> > humans are physically different from other apes in ways that can be
> > explained some kind of adaptation to movement through water. That is
> > the starting point upon which a detailed model has to be built and, of
> > course, argued over. But that fundemental point is one you steadfastly
> > refuse to accept, even as a possibility. It seems to me that
> > aquasceptics have dug themselves into such a staunchly ant-AAH trench
> > that they cannot now even admit the most absurdly mild of
> > possibilities - in your case, even that our ancestors lived closer to
> > water than ape ancestors did. This is, in a way, understandable. You
> > clearly realise that admitting anything, on this slippery slope, would
> > be tantamount to an admission that the AAH was actually right all
> > along. Because if we lived by water more than chimps then, logically,
> > we must have moved through it more too. If we moved through it more,
> > then - through the laws of natural selection - clearly we'd have
> > become more adapted to it too. All you'd be left with then is pathetic
> > arguments about the 'degree' of aquaticism - claiming that these
> > aquatic pressures would have been so slight as to have made no
> > difference at all - an impossible position to hold.
>
> Straw men again, Algis? I would have to label myself an "aquaskeptic".
> Have you ever seen me refuse to admit possibilities?
No, but then I've not had the pleasure of debating with you very often
(if ever) before.
> Or more specifically, refuse to admit particular pieces of data?
So what do you say about the Sharp & Costill data? What about the
bonobo wading data? Can you accept that they are bits of data in
favour of the AAH? That would be encouraging.
> I have no
> problem with human ancestors living near water, exploiting water
> resources, or even that some pieces of evidence could be used to claim
> a semi-aquatic past.
I get the feeling there's a big BUT coming here...
> What I *do* have a problem with is the misuse of
> evidence as independent points of data when other points of data
> contradict, discredit, or even at the most basic level make the data
> equivocal.
So do I.
> I *do* have a problem with the idea of human ancestors as
> having physiologically adapated to extensive time in the water because
> I simply do not see any logical consistency and credibility of
> evidence to see physical adaptation to living in a water environment.
My view is water-side not water-living. It seems to me that we are
clearly better adapted to moving (wading, swimming, diving) through
water than apes are. It's logical that that was the result of natural
selection.
> What I *do* have a problem with is the leap of logic from using water
> resources, and their importance in the evolution of the human clade,
> to the claim of physical adaptation to the water.
> What I *do* have a
> problem with is the intellectual dishonesty of Marc, and his reuse of
> information shown to be unreliable, incorrect, or equivocal, and its
> use as the roseta stone of evolutionary biology. What I *do* have a
> problem with is the intellectual dishonesty of Marc, and is explicit
> refusal to admit he has been told something before, and to go out of
> his way to force others to redo the same refutation/discrediting of
> some particular point, such that people eventually tire of having to
> redo the same typing over and over and over because every single time
> he makes X claim and the same points are brought up again and again,
> he claims to know nothing about them.
> What I *do* have a problem with
> is you and Pauline continually referring to a straw man of "savanna
> theory" so that you can dismiss it out of hand and sit back and bask
> in the supposed self-evidence of the aquatic idea based on relative
> credulity, even after that point has been brought to your attention
> *multiple times*.
I don't remember going on about savannah much lately. Ok. I'll make a
real effort to avoid doing so in future.
> I also have a problem with you and Pauline both
> refusing to ever make a peep on any thread (either here or in AAT
> group) that contradicts Marc, no matter how far off the deepend he is
> on a particular issue, no matter how much he *lies* about something
> and has the evidence that has has throw right back in his face, and
> then every time someone posts some inane anectdote, you chime in with
> "interesting! that sure seems to support aat! what do you think,
> marc?".
Mmm, are you sure you've got the right person here?
> Yes, I realize both of you haven't spent much time in AAT group in the
> past year posting anyway, but when you both were posting daily on many
> or even most topics, you scrupulously avoided contradicting Marc, even
> when he was being obviously intellectually dishonest.
I've had a few run-ins with Marc and incurred his wrath once or twice.
Time's too short. I agree with him more than I agree with some of the
folks here. It's more fun and challenging to argue with people who
disagree.
> You state:
>
> "You clearly realise that admitting anything, on this slippery slope,
> would be tantamount to an admission that the AAH was actually right
> all along."
>
> Now, can you really claim you are being intellectually honest? Do you
> really intend to state that if someone says, "Yes, a reduction in hair
> could produce a minor and *insignificant* reduction in drag when in
> the water." That they are admitting that AAH is "actually right all
> along"?
Ok, when you put it like that, it's just daft. I do think that our
dependence on water for sweat cooling indicates our ancestors lived
closer to reliable water sources than apes' did. And if true, it is
likely they'd have moved through the water more too and it follows
logically from that that they'd have evolved better wading, swimming
and diving traits.
Anyone that understands evolution would have to admit that even mild
pressure can have dramatic effects over millions of years and so (the
point I was trying to make) if that person was determined to keep
dismissing the AAH out of hand they'd have to be careful not to admit
that our ancestors lived too close to water at all. It's a slippery
slope towards admitting the AAH - that's all.
> It is a just-so story, Algis.
Of course it is. I know that. But aren't they all?
> Maybe its correct, it could be after
> all. But it is a just-so story (you set up the premise and devise a
> manner that it could have proceeded from that premise to the known
> present), not one based on physical evidence. Now, there are lots of
> just-so ideas in paleoanthropology (how could there not be with so
> little evidence?), but that doesn't make your's any better than those.
We could argue about that. But it's getting late...
> What is the unequivocal evidence supporting adaptation to a water
> environment?Exploiting the environment is not good enough, we
> obviously do and did do that.
We move through water better than the nearest in our clade. That's
unequivocal.
> Positing a hypothesis and show how it
> could happen is not good enough, there are hundreds of those. Showing
> evidence that is equivocal with other ideas is not good enough, if the
> evidence works as well with another idea(s), why pick yours over
> those?
How many of the models you know explain why we are better swimmers
than chimps?
> I have no problem with creating a hypothesis like you have done. I do
> have a problem with you supporting it completely with just-so stories,
> equivocal evidence, and appeals to credulity and then expecting for
> people to support it as self-evident. Its perfectly fine to create a
> hypothesis that you believe is correct, or more correct than others.
> It is not perfectly fine to be so dismissive of anything or anyone
> that doesn't agree, and those that do not see it as credulous just
> because you do, nor to act as if someone that won't agree with you is
> close-minded. Don't get me wrong, its just as obvious that many of the
> people you argue with here have the same fault at times or even all
> the time for some of them, but that doesn't excuse you doing the same.
I hope you don't think I'm dismissive of people that don't agree with
me. I don't think I've done that.
> Does it really matter what hardy believed? This is for both of you.
> Just let it go. Ideas presented in a non-professional magazine by a
> non-specialist 40 years ago aren't so important in an of themselves
> they should be used to detract from an idea someone else has that is
> similar or even inspired by the original.
You're probably right.
> > Hardy had made an observation (sc fat in aquatic mammals) and made the
> > analogy with humans after reading about sc fat in humans. He realised
> > that the theory was controversial so kept it 'in the dark' for thirty
> > years before going public with it. He was, I feel, a rather more
> > modest than you portray him to be.
>
> He also believe in ESP, didn't he? =P Just another reason to keep him
> out of this entirely. He's dead, he didn't spend his life creating or
> defending an aah/aat theory, so why not keep it to those that have?
Yep, I think so. He spent most of his later life trying to find some
marriage (I won't use the word hybrid) between science and religion.
Fair point. Elaine Morgan really deserves most of the credit, just for
keeping the idea alive.
> > Remember he only posed the question "Was Man more aquatic int he
> > past?" More aquatic, note. The press knee-jerk reaction was to laugh
> > at the idea and assume he was talking about dolphins and mermaids.
> > Unfortunately, it seems that most PAs are still stuck in that
> > knee-jerk first impression even today.
>
> No, they aren't. Most are incredulous because they have been fed on
> other ideas they whole career, and when they see the contradictions
> and level of evidence being used by the most vocal aat/aah adherents
> they lump them together with the ufo people. It isn't a knee-jerk
> reaction, its a delayed reaction informed by the fallacies that some
> aah/aat adherents refuse to abandon.
I do think that if the AAH is going to get any serious recognition it
will need people to go through the ranks as 'trained PAs' who use
proper scientific methods and peer-reviewed work. There's no doubt
that it has suffered from the perception by PAs of the proponents of
the theory. I do think it's a bit unfair to expect non-specialists to
have the highest standards though and, although there are valid
criticism you can make about their methods I hardly think the PA world
has been a shining example of openness and objectivity here. It often
seems more like a religuous clique. So, fault on both sides.
> When it gets boiled down to aat/aah being an idea of exploitation of
> marine or riverine resources, you get a better response. When it comes
> to claiming a physical adaptation to those resources or manner of
> living, there is more skepticism, but people listen. When you fall
> back on the same tired stuff mentioned before, dismiss honest
> incredulity, or depend on just-so stories to support the position,
> then they run screaming for the hills.
There's a great need for more data, that's all. Very few studies have
been done to yield that data so, surprise, surprise, people are
skeptical.
> There are a lot of problems with academia, and one of those is the
> resistance to new ideas. So even when someone has a "Great Idea" there
> is resistance. But when someone refuses to critically examine their
> own position, or the position of those that lend them some support
> just to maintain that support, then you reap what you sew in terms of
> credibility.
Fair enough.
> > All he was trying to do was to stimulate a debate and to encourage
> > scientists to test the theory. The response was appauling. Almost
> > nothing was done and the only words that were said were ridicule.
>
> How exactly is the "theory" tested? If it was testable there would be
> a lot less problems with the various AAH/AAT scenarios. How do we test
> your scenario, Algis? Is there a way? Is there any piece of evidence
> we might find that will vindicate your scenario?
I can make a number of predictions which the model would expect. The
model could easily be refuted or modified if they proved false.
For example: I'd expect bipedal wading to be more efficient than
quadrupedal wading. More body hair shaved off giving greater drag
reduction. I'd expect some early bipeds (e.g. A'piths but not the
earliest)to have a form of locomotion - that could be tested against
the fossil record - that reduced drag whilst wading. I'd expect fossil
hominids to be found on Danakil.
> Or are we forced to
> deal with just-so stories based on credulity and the fact that you can
> wiggle the hypothesis around so that we are left with only equivocal
> evidence regarding it?
Just like most of the other models then, really.
> > It's not that it failed. Hardy never had a model as such. He made no
> > predictions, had the barest timescale and offered no evidence other
> > than human anatomy analogies with aquatics. He was merely asking a
> > question so how could it have failed? The failure, if there was one,
> > must lie with the paleoanthropologists of the 1960s who simply ignored
> > it completely rather than having an ounce of proper scientific
> > curiosity about the idea.
>
> Now this is ridiculous. If the aquatic ideas are so important and
> convincing, the failure was in the adherents to provide real evidence
> in support of it, and to argue with what evidence they do have
> honestly.
I think there was a lack of imagination at that crucial time in 1960
when Hardy was told to 'never do that again' by Le Gros Clark. If one
of the top PAs had seriously considered it then and come up with a
modest, plausible version, it would be mainstream today. I really
believe that.
> Do you realize that many people working in physical
> anthropology haven't even heard of aat type hypotheses? That's right.
> Ask many, and they don't know what they hell you are talking about.
I believe you. It's not taught, it's not even in the textbooks as a
possibility - so how could they know about it?
> Hell, whenever someone even tries to give the benefit of the doubt
> they get run off by the bullshit. Please explain why someone can spout
> off an idea in an non-academic setting, an opinion piece, and it is
> now the responsibility of those in the field to waste their time and
> resources in investigating it?
As I said, immediately after Hardy (FRS, remember) 'came out' there
was an opportunity for someone to take it seriously and come up with a
modest version. They didn't. Instead they just sneered. It's not that
ridiculous an idea and there are significant bits of data which
support it in on way or another.
> The idea is not so self-evident that it has drawn people interested in
> working on it academically. Most that have even had the thought of
> doing so get so disgusted by some particular supporters and the
> standard of evidence that they go on to other things. That is the
> failure of the idea. That is the failure of those that support it (or,
> more importantly, those that have supported it for decades), not the
> failure of paleoanthropologists.
PA is riddled with academic inculturation. That's why you get the
students from institution A arguing for A's positon generations after
professor A first published and institution B's students arguing the
opposite. The fact that institutions A-Z are all anti-AAH is therefore
no surprise.
> Why not try and do real science by investigating specific problems and
> searching for the best answer the evidence supports rather than
> starting with a general theory and trying to build into that theory?
Yep. Specific problem: origin of bipedalism. Specific hypothesis:
Wading.
> Hybridisation of populations does not explain the differences in
> chomosome number in humans and the great apes. The fusion in the human
> clade is an interesting question, but your scenario can't explain it.
I'm not a geneticist and so don't understand it very well but Max
King's book listed a number of models which included hybridisation and
pointed me in the direction of Michael Arnold and Alan Templeton. I've
been going through Templeton's recommended reading list and although
most of it is over my head it seems that hybridisation as a model for
speciation and chromosome number change is a possibility. So you might
be wrong to say my scenario can't explain it.
> Your hybridization event and everything that could be construed to
> support it is speculation. You're entitled to your speculations, but I
> would suggest you don't marry another broad speculation into the
> already broad one of AAT/AAH.
Personal incredulity and unpopularity are not a factor for me here. A
watered down AAH makes sense to me and so does a hybridisation event
for the Homo sapiens speciation. I've not read anything to contradict
them yet although, it's true, there's not much solid data in favour
yet either.
> The chromosome change was a fusion of two chromosomes into one.
Yes, but how? How likely was that to happen once? How vanishingly less
likely that it might happen twice in the same place at the same time
so that the F1's can interbreed and begin the new 46-chromosome
species? Remember how lethal even minor chromosomal mutations are. How
likely is it to have srvived in aheterozygous form?
> Hybridisation of populations (gene flow) does not explain this in any
> way shape or form.
I think it might.
> The event occurred and spread among a population.
How? Considering problems above.
> No if and or buts about it Hell, a hybridisation of two populations
> (one with the original 48 and one with 46) just gives another chance
> for selection and/or genetic drift to grind the 46 chromosome types
> out of the population, making it more difficult for the change to
> spread species wide if it has to open up the potential breeding
> population and drop the frequency of those with 46.
That would be right if I was postulating a 48-46 hybrid but I'm not.
I postulate a hybridisation of two populations of 48 and the
hybridisation itself giving rise to the chromosome fusion. That way
you'd have a much greater chance of a number of 46 chromosome
individuals around at the same time. Enough to form a small group of
nascent Homo sapiens which were instantly genetically isolated from
teir parental 'species'.
> Keep away from the strawman of savanna if you want others to stay away
> from the strawman of dolphins and mermaids.
I'll do it if you do.
> Objective people are skeptical by nature, otherwise they would latch
> on to the first thing that strikes their fancy and subjectively judge
> everything else from that position
> *cough*likemanyaatsupporters*cough*. Maintaining objectivity means you
> maintain skepticism of *everything* and it is up to those that claim
> to support one subjective interpretation to convince them.
> He asked you questions, and didn't like your answers, and addressed
> them, didn't dismiss him. That makes him (at least in this exchange)
> objective.
What about being sceptical about other people's scepticism? That must
make me super-objective, right?
Algis Kuliukas
Jason Eshleman
Algis Kuliukas <al...@RiverApes.com> wrote:
>dkr...@yahoo.com (Abazagaroth) wrote in message news:<fc59222d.03050...@posting.google.com>...
>> al...@RiverApes.com (Algis Kuliukas) wrote in message news:<77a70442.03050...@posting.google.com>...
>> This is why people get so frustrated with Marc, as he has this down
>> pat. Whenever someone points out a single problem, he turns the
>> problem back out onto the overarching theory in an attempt to minimize
>> the importance of the original point, and then claim "no one has
>> presented 1 argument against" his scenario (because in his mind the
>> original point is no longer an "argument against" since he has
>> deflected it back onto the overarching theory which is still
>> supporting by all the other pieces of "evidence"). It doesn't matter
>> if some, many, most, or even all of the points in support of the
>> theory have been discredited or shown to be equivocal, since he
>> refuses to stop using this - at best - illogical and naive method or -
>> at worst - intellectually dishonest method.
>
>I have shared your frustration with some of his tactics from time to
>time. I am reluctant to criticise more than that because I respect his
>enthusiasm. One thing I find very distasteful is the level of
>arrogance and downright nastiness that this debate seems to generate.
>It's not as if anyone *knows* what happenned. I know Marc is a guilty
>of this as anyone but he must feel, sometimes, he is fighting off the
>whole world on his own. I've had the pleasure of meeing Marc and found
>him to be a charming, very intelligent and amazingly well-read man who
>is honestly trying to push our understanding further. Sometimes he
>gets too passionate but any enthusiastic person is guilty of that from
>time to time.
Many of Marc's tactics just identify him as a delusional whose delusions
make him act like a real asshole. A bigger problem though is his extreme
libery with factual information, a consistent pattern of misrepresenting
facts. Perhaps he is charming in person (I wouldn't know--despite his
repeated referencing of talk abstracts from the AAPAs, he doesn't actually
appear to attend these meetings) but I suspect that he still takes logical
liberties (eg the completely unsubstantiated claim that "Proboscis are the
most bipedal monkey; that there was "probably" a lot of water at Laetoli;
eg, saying that stratocladistics support his phlogenies, when he's in
fact not done any such analysis in his publicationss; the claim that seals
are abundant thermoregulatory sweaters [based, if you actually follow the
trail, back to a single severed seal flipper that produced beads of liquid
under a lightbulb]). It's these unscientific statements that at this
point I can only conclude mark him as intentionally ignorant or completely
psychotic, that are his real problems.
There's no reasonable defense for the stuff he pretends is science.
Standing in line with what he's doing, not on a social standpoint, but on
the aforemention scientific issues, makes you look really really bad.
Charles
Ross Macfarlane wrote:
much to clark's surprise... I agree.
wr
c
Marc Verhaegen
"Pauline M Ross" <pmr...@ross-software.co.uk> wrote in message
news:n10nbvg915qtqhouv...@4ax.com...
> But I do disagree violently with Marc's approach - I think all the ad
hominem stuff is counter-productive and brings the whole AAH into disrepute
(and your post basically confirms that). And I've told him what I think many
times, but I don't suppose he's going to change now, do you? Which makes me
wonder why some of the regulars here continue to go round and round with him
... very strange. -- Pauline Ross
:-D
Marc
Marc Verhaegen
"Richard Wagler" <taxi...@shaw.ca> wrote in message
news:3EBBD6D3...@shaw.ca...
> I read that article too. Not a bad piece. Too bad you only take out of it
what you want. Still there were very dry areas in Pliocene Africa - Kanapoi
comes to mind - and hominid fossils have been found there.
Kanapoi KNM-KP 29281 A.anamensis: Fish, aquatic reptiles, kudus and monkeys
are prevalent. 'A wide gallery forest would have almost certainly been
present on the large river that brought in the sediments' (Leakey et al.,
1995).
Marc Verhaegen
"Jason Eshleman" <j...@vidi.ucdavis.edu> wrote in message
news:b9h3t7$job$1...@woodrow.ucdavis.edu...
> liberties (eg the completely unsubstantiated claim that "Proboscis are the
most bipedal monkey
If you knew anything on primatology you would have indicated all the more
bipedal monkeys.
> ; that there was "probably" a lot of water at Laetoli;
This is what I published on Laetoli:
- " Garusi-Laetoli L.H. A. anamensis or afarensis: Teeth and mandible
fragments, the hardest skeletal parts which are frequently left over by
carnivores (Morden, 1988), come from wind-blown and air-fall tuffs (Leakey
et al., 1976). Cercopithecine and colobine monkeys are present (Protsch,
1981; Leakey et al., 1976)."
- "The list shows that some very early hominids, more than later
australopithecines, have been found near lacustrine molluscs (Lukeino and
Tabarin ca. 6.5 and 5 Myr BP). Ardipithecus ramidus, supposedly another
early hominid, must have lived in a wooded habitat, amid predominantly
colobine monkeys (Aramis ca. 4.5 Myr BP). Pliocene australopithecines ca.
4-3 Myr BP apparently frequently dwelt in warm and humid, more or less
closed environments (gallery forest or wooded habitat in Kanapoi, Chad,
Hadar, Makapansgat, but inconclusive for Garusi-Laetoli). Pleistocene robust
australopithecines since 2.5 Myr BP probably lived in generally dryer and
more open landscapes (grassland in Kromdraai and Konso), but their remains
lay in riverbanks, lagoons, marshes, lake-margins, near papyrus (Olduvai)
and reed (Kromdraai, Olduvai, Chesowanja). Although 'all nine Konso A.
boisei specimens were recovered among the predominantly dry grassland fauna
of KGA 10' (Suwa et al., 1997), this does not mean that they lived in a
savanna milieu, since 'nearby subsites were also moist and wooded' (Delson,
1997). Fragmentary fossils like those of Laetoli and Konso are often the
remains of carnivore meals (Morden, 1988). Leopards, which preyed upon
australopithecines, prefer to feed in dry circumstances and therefore drag
away their prey, sometimes several hundred meters (Brain, 1981)."
http://allserv.rug.ac.be/~mvaneech/Fil/Verhaegen_Human_Evolution.html
> eg, saying that stratocladistics support his phlogenies
Lying as usual? Where did I say that??
>, when he's in fact not done any such analysis in his publicationss
My analyses suggest the large E.African apiths belong to Gorilla (esp.
boisei), and the S.African africanus-robustus belong to Pan.
(AFAIK, my analyses are the only ones that use orangs as outgroups, and
chimp & gorillas as ingroups, cf.D.Curnoe 2003 "Problems with the use of
cladistic analysis in palaeoanthropology" Homo 53:225-234: "...The genetic
proximity of humans, chimps & gorillas has important implications for
cladistic analyses. It is argued that chimps & gorillas should be treated as
ingroup taxa , an alternative outgroup such as orangs should be used, or an
(hypothetical) ancestral body plan developed. Making chimps & gorillas
ingroup taxa would considerably enhance the biological utility of
anthropological cladograms. ...")
> ; the claim that seals are abundant thermoregulatory sweaters
Only idiots like you doubt this.
> [based, if you actually follow the trail, back to a single severed seal
flipper that produced beads of liquid under a lightbulb
Lying again? What is this nonsense based upon?
Jim McGinn
> And why shouldn't it? A huge mass of evidence says early
> hominids lived in savannah environments (propoerly defined).
No. It was not treeless savanna. It was treed lacustrine (lakeside
or stream side, etc.) locations. Where you been. This is kind of old
news now.
> The whole problem is that Morgan et al have taken the Dartian
> position as some kind of orthodoxy and with the changes in
> the picture that research beginning 40 years ago mandated
> have tried to use this to promote the ridiculous idea that early
> hominids never lived in savannah environments of any description
> whatsoever. Dart was a perpetual outsider not a main pillar
> of some orthodoxy. Read what PAs were actually saying and
> forget 'popular' representations. The standard AAT critique of
> PA is absolute junk - a classic definition of a strawman.
Oh, so it's all Morgan et al that is at fault here. It's not those
that continue to maintain the notion of our ancestors travelling in
band over treeless habitat in hunting, gathering, scavenging groups.
This is comical.
>
> >
> >
> > Of course there have been adjustments over the years, notably
> > bipedalism has been pushed back into the trees and the definition of
> > 'savanna' has expanded,
>
> has it?
Most definitely. Get used to it.
>
> > but the original idea of a hot, dry
> > environment still informs a great deal of PA thinking. I have quoted
> > one professional lamenting that researchers are still fixated on a
> > Serengeti-type environment,
>
> I read that article too. Not a bad piece. Too bad you only
> take out of it what you want. Still there were very dry areas
> in Pliocene Africa - Kanapoi comes to mind - and hominid
> fossils have been found there.
It wasn't dry then.
In any event the scavenging
> studies done in dry savannahs kind of confirm the point that
> a living was avaiable to any hominid who might have been
> in these sorts of places were they of a mind to scavenge.
Typical savanna idiocy. It should be obvious to you that if an animal
with the relatively non-encephalized brain of chimps were to shift
lifestyles to that of a scavenger their evolution would more likely
parallel that of hyena (or some other scavenger) than it would the
cultured, communicative, and cooperative animal that us humans turned
out to be.
Jim
Algis Kuliukas
> There's no reasonable defense for the stuff he pretends is science.
> Standing in line with what he's doing, not on a social standpoint, but on
> the aforemention scientific issues, makes you look really really bad.
What's this 'stand in line' argument? Sounds like a recipe for a
witch-hunt to me - 'Are you with him, or with us?'
I agree with Marc that human (and probably early hominoid) evolution
was influenced by water. I agree with Marc that the earliest bipeds
were probably 'aquarboreal' waders. I agree with Marc that moving
through water remained a significant pressure throughout our
evolution. I've always been very impressed with his knowledge and his
ability to cite references to back up his arguments (although
sometimes tedious, sometimes repetitive and sometimes, apparently, in
error) is actually to be applauded. Very few others bother to give as
many references as he does. In particular, Marc impresses me because
he was predicting a MRCA of Pan/Gorilla/Homo that was already a wading
ape when almost everyone else (me included) had something akin to a
chimp in mind. I moved much closer to Marc's line (accepting the
aquarborbeal model) upon the discovery of Orrorin in Dec 2000.
I agree with many (probably most) of his ideas but that doesn't mean
I'm standing 'in line' with him on everything.
I disagree with Marc about other things: Mainly his tactics (witness
his reply to your posting - calling you an idiot again. I really think
that is counterproductive in the biggest way possible. I know that you
are not an idiot, Jason.) I also disagree with some of his uses of
comparative data. Overstretching the case can also be very
counter-productive.
I disagree with parts of his model too: In my opinion it stresses too
much coastal/marine and not enough riverside/fresh-water. I think he
downplays the imortance of fossil data - thus lessening the importance
of the African hominoidae hypodigm and overplays the idea that much of
this evolution happenned on coastlines - where all the fossils are
conveniently covered by the seas.
We've had other run-ins too about minor points of my model. I didn't
like the experience. Like you, he can come across as being very
self-righteous and arrogant when you're arguing against him.
So who else am I 'in line' with? How about you?
I agree with you about Darwinian natural selection, presumably about
the Out of Africa theory and about the importance of the scientific
method. Does that mean you are standing in line with me? How does that
feel to you?
I wished that you and Marc would see that you are not actually all
that far apart yourselves. Why don't you both start trying to see
common ground instead of finding fault with eachother like a pair of
adolescent boys high on testosterone?
Algis Kuliukas
Bob Keeter
"Algis Kuliukas" <al...@RiverApes.com> wrote in message
news:77a70442.03050...@posting.google.com...
news:<b9h3t7$job$1...@woodrow.ucdavis.edu>...
>
Snippage. . . .
> I agree with many (probably most) of his ideas but that doesn't mean
> I'm standing 'in line' with him on everything.
>
Good!
> I disagree with Marc about other things: Mainly his tactics (witness
> his reply to your posting - calling you an idiot again. I really think
> that is counterproductive in the biggest way possible. I know that you
> are not an idiot, Jason.) I also disagree with some of his uses of
> comparative data. Overstretching the case can also be very
> counter-productive.
Hmmm. . . . . . Wasnt that about what got "snipped" when I said it?
> I disagree with parts of his model too: In my opinion it stresses too
> much coastal/marine and not enough riverside/fresh-water. I think he
> downplays the imortance of fossil data - thus lessening the importance
> of the African hominoidae hypodigm and overplays the idea that much of
> this evolution happenned on coastlines - where all the fossils are
> conveniently covered by the seas.
Good. Straight up logic rather than hystrionics!
> We've had other run-ins too about minor points of my model. I didn't
> like the experience. Like you, he can come across as being very
> self-righteous and arrogant when you're arguing against him.
>
Not exactly the kind of image you want at the "spokesman" for the AAH? Dont
blame you at all. Seem to have one of those over in the SAH world as well!
For some unknown reason, I tend to get even more upset with him that I do
with Marc! (actually not all that unusual at all if you think about it a
bit!).
> So who else am I 'in line' with? How about you?
>
> I agree with you about Darwinian natural selection, presumably about
> the Out of Africa theory and about the importance of the scientific
> method. Does that mean you are standing in line with me? How does that
> feel to you?
>
> I wished that you and Marc would see that you are not actually all
> that far apart yourselves. Why don't you both start trying to see
> common ground instead of finding fault with eachother like a pair of
> adolescent boys high on testosterone?
>
Well, the trick is that one side or the other has to make the "break" from
the mold (and then the other has to follow. Would you not say that Marc has
been given several different opportunities to "step up" and match certain
initiatives that have been offered? Guess he just does not want to play.
Either that or he is just plain deathly afraid that he will have to back off
of some of the "revelations".
Oh well. we all have our burdens to carry, right?
Regards
bk
Algis Kuliukas
Well said, Pauline. I agree 100%.
Algis Kuliukas
Algis Kuliukas
> > He asked you questions, and didn't like your answers, and addressed
> > them, didn't dismiss him. That makes him (at least in this exchange)
> > objective.
> >
> > CDK
>
> Thank you sir. Very civil of you (at least in this exchange :-)...
>
> Ross Macfarlane
That might make you feel better, Ross, but I know and you know that
you simply avoided about half of the points I made in that thread.
Algis Kuliukas
Pauline M Ross
<fa20...@skynet.be> wrote:
>Kanapoi KNM-KP 29281 A.anamensis: Fish, aquatic reptiles, kudus and monkeys
>are prevalent. 'A wide gallery forest would have almost certainly been
>present on the large river that brought in the sediments' (Leakey et al.,
>1995).
Now, Marc, don't distract us with paleoanthropology, when everyone
finds it much more fun to rant about how awful you are... ;-)
--
Pauline Ross
Gerrit Hanenburg
Most of the Kanapoi hominid specimens were recovered in situ from
paleosols. These indicate relatively open and semi-arid conditions at
Kanapoi at the time. This is not compatible with extensive wetland
conditions.
Wynn, J.G. (2000). Paleosols, stable carbon isotopes, and
paleoenvironmental interpretation of Kanapoi, Northern Kenya. JHE 39:
411-432
Abstract:
This study uses the interpretation of paleosol features at Kanapoi,
Kenya (4·2-3·4 Ma) to reconstruct the ecosystem occupied by
Australopithecus anamensis. The paleosols at Kanapoi provide a unique
and fortuitous opportunity, in that the bulk of the hominid specimens
derive from paleosols, providing direct evidence of the environment
that the Kanapoi hominids occupied. Seven named types of paleosols
are recognized at Kanapoi, each representing a trace fossil of the
local ecosystem during soil formation. The hominid-bearing Dite
paleosols provide evidence that A. anamensis inhabited areas of
semi-arid, seasonal climate regimes with mean annual precipitation
ranging from about 350-600 mm. The in situ hominid collections from
Dite paleosols show that A. anamensis at least occasionally occupied
relatively open low tree-shrub savanna vegetation formed in well
drained settings, and may have preferred these conditions over other
poorly drained soils. The relatively open conditions of Dite paleosols
existed within a spatially variable ecosystem, characterized by a
mosaic of environments, ranging from forb-dominated edaphic grassland
to gallery woodland, providing a larger view of the mixed
ecosystem in which A. anamensis lived. Synthesis of paleoenvironmental
indicators of A. anamensis at Kanapoi and Allia Bay, Kenya
suggests that as early as 4Ma hominids thrived in varied ecosystems.
Gerrit
Pauline M Ross
<G.Han...@inter.nl.nomail.net.> wrote:
>>[Marc] Kanapoi KNM-KP 29281 A.anamensis: Fish, aquatic reptiles, kudus and monkeys
>>are prevalent. 'A wide gallery forest would have almost certainly been
>>present on the large river that brought in the sediments' (Leakey et al.,
>>1995).
>
>[Gerrit] Most of the Kanapoi hominid specimens were recovered in situ from
>paleosols. These indicate relatively open and semi-arid conditions at
>Kanapoi at the time. This is not compatible with extensive wetland
>conditions.
So that's open and semi-arid conditions, with a wide gallery forest
and a large river...??? Or are you saying that Leakey et al are wrong?
--
Pauline Ross
Bob Keeter
Actually, Pauline, you have pointed out the ULTIMATE defense against those
of us who say that Marc (and others on both sides of the discussions here)
simply pollute the scientific discussion of paleoanthropology with
egotisical ranting, insulting ad hominem, and juvenile temper tantrums;
thereby doing far more disservice to their views than anything! Counter
that with good solid (even if debatable!) science, and we would not have any
option other than to drop the accusations and engage in scientific
discussions (unless some of us chose, regretably, to descend into the same
little pathetic cycle of hateful rhetoric that gets Marc in so much
trouble)!
Real, honest science is the "Achilles heel" of the "Marc is a jerk and an
insult to science" hypothesis, and I freely and proudly admit to that
weakness! Lets see if he is strong enough, mature enough, confident enough
of his ideas, or whatever to exploit that weakness! Betcha on long odds!
8-)
Regards
bk
Bob Keeter
Gerrit,
Would not the above be very consistent with the monsoon-driven,
"Serengeti-style" savanna of today, even including the fish and reptiles?
You have the "wet season" with plenty of surface water to support fish and
reptiles. The rivers and streams dry up leaving an annual deposit of fish
and reptile bones ffrom those that "did not make it". And you still get
plenty of bones from the "dryland" types that inhabit the area year round.
Regards
bk
Gerrit Hanenburg
>>>[Marc] Kanapoi KNM-KP 29281 A.anamensis: Fish, aquatic reptiles, kudus and monkeys
>>>are prevalent. 'A wide gallery forest would have almost certainly been
>>>present on the large river that brought in the sediments' (Leakey et al.,
>>>1995).
>>
>>[Gerrit] Most of the Kanapoi hominid specimens were recovered in situ from
>>paleosols. These indicate relatively open and semi-arid conditions at
>>Kanapoi at the time. This is not compatible with extensive wetland
>>conditions.
>So that's open and semi-arid conditions, with a wide gallery forest
>and a large river...??? Or are you saying that Leakey et al are wrong?
No, once again I'm only pointing out the dishonesty of Verhaegen who
only presents part of the available information. Leakey et al. (1995:
571) wrote: "Dry, possibly open, wooded or bushland conditions are
indicated by the kanapoi mammalian macro- and microfauna, although a
wide gallery forest would have almost certainly been present on the
the large river that brought in the sediments." At the time of writing
the paleosol analysis wasn't available yet.
The presence of channels with forest zones is a normal feature of
savanna. You'll find it plenty in the modern Serengeti-Mara ecosystem.
Gerrit
Gerrit Hanenburg
>> Abstract:
>> This study uses the interpretation of paleosol features at Kanapoi,
>> Kenya (4·2-3·4 Ma) to reconstruct the ecosystem occupied by
>> Australopithecus anamensis. The paleosols at Kanapoi provide a unique
>> and fortuitous opportunity, in that the bulk of the hominid specimens
>> derive from paleosols, providing direct evidence of the environment
>> that the Kanapoi hominids occupied. Seven named types of paleosols
>> are recognized at Kanapoi, each representing a trace fossil of the
>> local ecosystem during soil formation. The hominid-bearing Dite
>> paleosols provide evidence that A. anamensis inhabited areas of
>> semi-arid, seasonal climate regimes with mean annual precipitation
>> ranging from about 350-600 mm. The in situ hominid collections from
>> Dite paleosols show that A. anamensis at least occasionally occupied
>> relatively open low tree-shrub savanna vegetation formed in well
>> drained settings, and may have preferred these conditions over other
>> poorly drained soils. The relatively open conditions of Dite paleosols
>> existed within a spatially variable ecosystem, characterized by a
>> mosaic of environments, ranging from forb-dominated edaphic grassland
>> to gallery woodland, providing a larger view of the mixed
>> ecosystem in which A. anamensis lived. Synthesis of paleoenvironmental
>> indicators of A. anamensis at Kanapoi and Allia Bay, Kenya
>> suggests that as early as 4Ma hominids thrived in varied ecosystems.
>Would not the above be very consistent with the monsoon-driven,
>"Serengeti-style" savanna of today, even including the fish and reptiles?
Affirmative.
(but noting that there's a rainfall gradient in the Serengeti today
from 500 mm in the dry southeastern plains to 1200 mm in the northwest
in Kenya. Kanapoi would have been at the dry end of the range).
>You have the "wet season" with plenty of surface water to support fish and
>reptiles. The rivers and streams dry up leaving an annual deposit of fish
>and reptile bones ffrom those that "did not make it". And you still get
>plenty of bones from the "dryland" types that inhabit the area year round.
There's a modern analog in the form of several large channel systems
in the Serengeti-Mara ecosystem (e.g. Mara R., Grumeti R., Orangi R.,
Mbalageti R.) with wet season floodplain zones that leave aquatic
debris in the dry season (in fact, the dry season is the most
productive period for traditional fishers in Africa because many fish
become stranded in shallow pools and channels where they can be caught
with little or no technology).
Gerrit
Marc Verhaegen
"Pauline M Ross" <pmr...@ross-software.co.uk> wrote in message
news:3idpbv0gm2090nnfo...@4ax.com...
> >Kanapoi KNM-KP 29281 A.anamensis: Fish, aquatic reptiles, kudus and
monkeys are prevalent. 'A wide gallery forest would have almost certainly
been present on the large river that brought in the sediments' (Leakey et
al., 1995).
> Now, Marc, don't distract us with paleoanthropology, when everyone finds
it much more fun to rant about how awful you are... ;-) -- Pauline Ross
I don't follow these guys. They talk about everything except the essence.
Marc
Marc Verhaegen
"Gerrit Hanenburg" <G.Han...@inter.nl.nomail.net.> wrote in message
news:jjmpbv4lih1o1kiv4...@4ax.com...
> >> I read that article too. Not a bad piece. Too bad you only take out of
it what you want. Still there were very dry areas in Pliocene Africa -
Kanapoi comes to mind - and hominid fossils have been found there.
> >Kanapoi KNM-KP 29281 A.anamensis: Fish, aquatic reptiles, kudus and
monkeys are prevalent. 'A wide gallery forest would have almost certainly
been present on the large river that brought in the sediments' (Leakey et
al., 1995).
> Most of the Kanapoi hominid specimens were recovered in situ from
paleosols. These indicate relatively open and semi-arid conditions at
Kanapoi at the time. This is not compatible with extensive wetland
conditions. Wynn, J.G. (2000). Paleosols, stable carbon isotopes, and
paleoenvironmental interpretation of Kanapoi, Northern Kenya. JHE 39:411-432
Abstract: This study uses the interpretation of paleosol features at
Kanapoi, Kenya (4·2-3·4 Ma) to reconstruct the ecosystem occupied by
Australopithecus anamensis. The paleosols at Kanapoi provide a unique and
fortuitous opportunity, in that the bulk of the hominid specimens derive
from paleosols, providing direct evidence of the environment that the
Kanapoi hominids occupied. Seven named types of paleosols are recognized at
Kanapoi, each representing a trace fossil of the local ecosystem during soil
formation. The hominid-bearing Dite paleosols provide evidence that
A.anamensis inhabited areas of semi-arid, seasonal climate regimes with mean
annual precipitation ranging from about 350-600 mm. The in situ hominid
collections from Dite paleosols show that A.anamensis at least occasionally
occupied relatively open low tree-shrub savanna vegetation formed in well
drained settings, and may have preferred these conditions over other poorly
drained soils. The relatively open conditions of Dite paleosols existed
within a spatially variable ecosystem, characterized by a mosaic of
environments, ranging from forb-dominated edaphic grassland to gallery
woodland, providing a larger view of the mixed ecosystem in which
A.anamensis lived. Synthesis of paleoenvironmental indicators of A.anamensis
at Kanapoi and Allia Bay, Kenya suggests that as early as 4Ma hominids
thrived in varied ecosystems.
Yes. "350-600 mm" & "well-drained" are not "very dry".
Marc Verhaegen
> >>>[Marc] Kanapoi KNM-KP 29281 A.anamensis: Fish, aquatic reptiles, kudus
and monkeys are prevalent. 'A wide gallery forest would have almost
certainly been present on the large river that brought in the sediments'
(Leakey et al.1995).
> >>[Gerrit] Most of the Kanapoi hominid specimens were recovered in situ
from paleosols. These indicate relatively open and semi-arid conditions at
Kanapoi at the time. This is not compatible with extensive wetland
conditions.
> >So that's open and semi-arid conditions, with a wide gallery forest and a
large river...??? Or are you saying that Leakey et al are wrong?
> No, once again I'm only pointing out the dishonesty of Verhaegen who only
presents part of the available information. Leakey et al. (1995:571) wrote:
"Dry, possibly open, wooded or bushland conditions are indicated by the
kanapoi mammalian macro- and microfauna, although a wide gallery forest
would have almost certainly been present on the the large river that brought
in the sediments." At the time of writing the paleosol analysis wasn't
available yet. The presence of channels with forest zones is a normal
feature of savanna. You'll find it plenty in the modern Serengeti-Mara
ecosystem.
For the Xth time, our view is based mostly on comparative data, and Kanapoi
in no way contradicts this. Dishonest are those who say Kanapoi suggests our
ideas are wrong.
Marc Verhaegen
"Algis Kuliukas" <al...@RiverApes.com> wrote in message
news:77a70442.03050...@posting.google.com...
(snipped :-))
> I disagree with parts of his model too: In my opinion it stresses too much
coastal/marine and not enough riverside/fresh-water.
Yes. This is a big problem in AAT thinking (eg, limited renal capacity - but
possibly due to reterrestrialisation). The dispersal of early Homo between
Algeria & Java in the beginning of the Pleistocene occurred no doubt along
the coasts, but this doesn't exclude a (later?) riverside evolution of our
ancestors. (Relative) arguments for the seaside once IMO are our behaviour
(hollidays, shells), durophagy & tool use, salty tears, sweat, rarity of
blue cones, the possibility of feeding exclusively on marine foods
http://www.netside.com/~lcoble/bible/water.html , loss of fur (cf. Mario's
ideas on salt & fur) etc.
> I think he downplays the importance of fossil data
I don't. I only dowplay the importance of fossils for our ancestors. Human
anatomy & physiology & behaviour say a lot about our ancestry. Fossils OTOH
only say something on the fossils, not directly on our ancestors. And since
IMO most or all apiths were closer relatives of chimps or gorillas than of
people, they're not very relevant for Homo evolution.
> - thus lessening the importance of the African hominoidae hypodigm and
overplays the idea that much of this evolution happenned on coastlines -
where all the fossils are conveniently covered by the seas
:-) Yes, but it's not my fault that sea levels changed a lot during the
Pleistocene.
> . We've had other run-ins too about minor points of my model. I didn't
like the experience. Like you, he can come across as being very
self-righteous and arrogant when you're arguing against him.
:-( I'm sorry, Algis, if that's your impression. IMO you don't have
convincing arguments for your hybridisation ideas, but I'm about the only
one here I believe who openly supports your ideas on partial sideways wading
in early hominids.
Marc
Jim McGinn
The hominid-bearing Dite
> paleosols provide evidence that A. anamensis inhabited areas of
> semi-arid, seasonal climate regimes with mean annual precipitation
> ranging from about 350-600 mm.
It seems that all hominid fossils are associated with seasonal
dessication (a dry season).
Jim
Jim McGinn
> Yes. "350-600 mm" & "well-drained" are not "very dry".
Yes, it ain't Gerrit's dry, treeless savanna but it
ain't no aquatic oasis either. Instead, it's well
watered part of the year and dry and dessicate for
the other part of the year.
Richard Wagler
Gerrit Hanenburg wrote:
Thanks, Gerrit. I was about to search out this article
and post it. How does it go.....biocenoses does not
equal thanatocenoses. Hope I haven't garbled the
spelling......
Rick Wagler
Richard Wagler
Pauline M Ross wrote:
Science marches on......Was Newton wrong because
Einstein reworked the whole business, Well, in a narrow
sense, he was, Bur science is not for narrow minds.
Rick Wagler
Richard Wagler
Marc Verhaegen wrote:
> Synthesis of paleoenvironmental indicators of A.anamensis
> at Kanapoi and Allia Bay, Kenya suggests that as early as 4Ma hominids
> thrived in varied ecosystems.
>
> Yes. "350-600 mm" & "well-drained" are not "very dry".
I live in a province of Canada where this approximates the
aannual rainfall. In the dry southern part of Alberta we have
typical shortgrass high plains grading to parkland with forest
patches in basically open country. To the north and west is
boreal and montane forest. Does this fit your description of
very wet.?
Rick Wagler
Bob Keeter
Snippage. . .
>
> For the Xth time, our view is based mostly on comparative data, and
Kanapoi
> in no way contradicts this. Dishonest are those who say Kanapoi suggests
our
> ideas are wrong.
>
Marc, in your sad little eyes, anything that does ot SCREAM aquatic ape is
dishonest.
One wonders if you dont try to hard to make the evidence that does exist
scream a bit
too loud. Truth is not measured in dB's! 8-)
Regards
bk
Bob Keeter
>
>> . We've had other run-ins too about minor points of my model. I didn't
>> like the experience. Like you, he can come across as being very
>> self-righteous and arrogant when you're arguing against him.
>
> :-( I'm sorry, Algis, if that's your impression. IMO you don't have
> convincing arguments for your hybridisation ideas, but I'm about the only
> one here I believe who openly supports your ideas on partial sideways
wading
> in early hominids.
>
Marc, I think in the above you betray one small fact that Ive suspected
for about as long as you and I have been trading jabs. . . You would offer
up support of Algis as a reason for him to support you! Forget the science,
forget the logic and reason, and just "play as a team" (with you as the
captain
of course!). "Personalities" particularly when coupled with a certain
"egocentric"
mindset are horrible for science, no matter which side of an arguement you
choose.
Algis thinks for himself and earns a big ( :-( ) from you. Sad.
Perhaps that "monolythic block" of Verhaugen disciples is not quite so
"in tune" with you and your rhetoric as you would like! Cant say that I
see anything wrong with that, can you? 8-)))
Regards
bk
Algis Kuliukas
> "Algis Kuliukas" <al...@RiverApes.com> wrote in message
> news:77a70442.03050...@posting.google.com...
>
> (snipped :-))
>
> > I disagree with parts of his model too: In my opinion it stresses too much
> coastal/marine and not enough riverside/fresh-water.
>
> Yes. This is a big problem in AAT thinking (eg, limited renal capacity - but
> possibly due to reterrestrialisation). The dispersal of early Homo between
> Algeria & Java in the beginning of the Pleistocene occurred no doubt along
> the coasts, but this doesn't exclude a (later?) riverside evolution of our
> ancestors. (Relative) arguments for the seaside once IMO are our behaviour
> (hollidays, shells), durophagy & tool use, salty tears, sweat, rarity of
> blue cones, the possibility of feeding exclusively on marine foods
> http://www.netside.com/~lcoble/bible/water.html , loss of fur (cf. Mario's
> ideas on salt & fur) etc.
The trouble is we seem to simultaneously have traits which indicate
fresh water dependence and scars of a marine past too. That's one of
the attractions of the hybridisation idea for me. It is as if our
marine traits have been half bred out.
> > I think he downplays the importance of fossil data
>
> I don't. I only dowplay the importance of fossils for our ancestors. Human
> anatomy & physiology & behaviour say a lot about our ancestry. Fossils OTOH
> only say something on the fossils, not directly on our ancestors. And since
> IMO most or all apiths were closer relatives of chimps or gorillas than of
> people, they're not very relevant for Homo evolution.
I can't argue with that Marc but what about early Homo? IMO seems to
indicate an African origin. And what about modern Homo sapiens? It
seems to me that the fossil and molecular data both back a second Out
of Africa and the replacement model.
> > - thus lessening the importance of the African hominoidae hypodigm and
> overplays the idea that much of this evolution happenned on coastlines -
> where all the fossils are conveniently covered by the seas
>
> :-) Yes, but it's not my fault that sea levels changed a lot during the
> Pleistocene.
That might be true Marc but any model has to be backed up with data.
> > . We've had other run-ins too about minor points of my model. I didn't
> like the experience. Like you, he can come across as being very
> self-righteous and arrogant when you're arguing against him.
>
> :-( I'm sorry, Algis, if that's your impression.
You see, Marc, you dismiss people as idiots too easily. I understand
your frustration when people disagree with you but the answer is not
to call them names and try to bully them into seeing that you're
right. That was the feeling I had when we disagreed about possibile
evolutionary explanation of the large infant brain. There might be no
answer but I think trying to find common ground is more likely to
succeed than pouring out insults.
> IMO you don't have
> convincing arguments for your hybridisation ideas, but I'm about the only
> one here I believe who openly supports your ideas on partial sideways wading
> in early hominids.
Mmm. The way I see it is that these are just ideas, Marc. I'd like to
depersonalise it. It's not so much that they are my ideas - Baird et
al 2000 I AFAIK are the first to publish that humans might be the
result of a hybridisation of hominids.
[Baird, Duncan M, Coleman, Joanna, Rosser, Zoe H, Royle, Nicola J
(2000). High levels of sequence polymorphism and linkage
disequilibrium at the telomere of 12q: Implications for Telomere
biology and Human Evolutions. American Journal of Human Genetics
Vol:66 Pages:235-250]
From abstract: "To explain the presence of a few diverged haplotypes
adjacent to the Xp/Yp and 12q telomeres, we propose a model that
involves the hybridisation of two archaic hominoid lineages ultimately
giving rise to modern Homo sapiens."
I accept that the hybridisation idea ia still very speculative but it
does answer a few question and I've not seen anything yet to
contradict it.
I don't know anyone who has ever suggested that Lucy waded using
lateral motion before but again, it's just an idea. It will stand or
fall based on the evidence. Thanks for your support on it but these
things are nothing to do with democracy. I'm sure you support it
because it seems to fit the facts, not because it was my idea. :-)
Similarly with the aquarboreal stuff. I support it because I think it
fits the facts best, not because it was your idea, Marc.
Algis Kuliukas.
Algis Kuliukas
> Marc, I think in the above you betray one small fact that Ive suspected
> for about as long as you and I have been trading jabs. . . You would offer
> up support of Algis as a reason for him to support you! Forget the science,
> forget the logic and reason, and just "play as a team" (with you as the
> captain
> of course!). "Personalities" particularly when coupled with a certain
> "egocentric"
> mindset are horrible for science, no matter which side of an arguement you
> choose.
> Algis thinks for himself and earns a big ( :-( ) from you. Sad.
I try to but we're all influenced by other people.
> Perhaps that "monolythic block" of Verhaugen disciples is not quite so
> "in tune" with you and your rhetoric as you would like! Cant say that I
> see anything wrong with that, can you? 8-)))
That's a bit unfair, Bob. Paleoanthropolgy is rife with academic
inculturation. It's not difficult to imagine that undergraduates at
university B lectured by professor B get taught a view of evolution
that is rather more B-like than A-like. And, surprise, surprise when
the brightest students go onto do their PhDs what are they most likely
to study A or B?
When it comes to the AAH, precatically every university is in camp B
and none in camp A. The only support of it at the moment is just a few
disparate academics and enthusiasts. The only 'team' play for A is
through newsgroups like this whereas B has a massive infrastructure of
'team playing' (let's call it by it's real name: peer pressure) going
on every day. And now, when you think you have spotted a bit of it
amongst AAH supporters you rush in to criticise. I hope you will now
turn your attention to the huge peer pressure which has discouraged
any PAs that are even in the mildest way sympathetic to the AAH from
publicly saying so. Witness Tobias. That would be objective, Bob.
Algis Kuliukas
Marc Verhaegen
The usual blabla. No contents. No regards.
Marc Verhaegen
> science is not for narrow minds.
Yes, Wagler, yes.
Marc Verhaegen
?? Nobody mentioned "very wet"! The man who began this "discussion" (you?),
said "very dry". Okidoki? Evading as usual. Yet found 1 argument against our
scenario?
Marc Verhaegen
> >> . We've had other run-ins too about minor points of my model. I didn't
like the experience. Like you, he can come across as being very
self-righteous and arrogant when you're arguing against him.
> > :-( I'm sorry, Algis, if that's your impression. IMO you don't have
convincing arguments for your hybridisation ideas, but I'm about the only
one here I believe who openly supports your ideas on partial sideways wading
in early hominids.
> Marc, I think in the above you betray one small fact that Ive suspected
for about as long as you and I have been trading jabs. . . You would offer
up support of Algis as a reason for him to support you!
Don't be ridiculous, bk.
1) I gave my arguments why I don't support Algis's hybridisation ideas.
2) I gave my arguments why I support most of Algis's wading ideas.
3) Instead of your blabla, you better give an argument against our scenario.
4) There are a lot of people here who think Algis might be correct (at least
partly), but who are afraid of the big mouths of the savanna believers. I'm
sick of this inquisition.
Marc Verhaegen
"Algis Kuliukas" <al...@RiverApes.com> wrote in message
> > > I disagree with parts of his model too: In my opinion it stresses too
much coastal/marine and not enough riverside/fresh-water.
> > Yes. This is a big problem in AAT thinking (eg, limited renal capacity -
but possibly due to reterrestrialisation). The dispersal of early Homo
between Algeria & Java in the beginning of the Pleistocene occurred no doubt
along the coasts, but this doesn't exclude a (later?) riverside evolution of
our ancestors. (Relative) arguments for the seaside once IMO are our
behaviour (hollidays, shells), durophagy & tool use, salty tears, sweat,
rarity of blue cones, the possibility of feeding exclusively on marine foods
http://www.netside.com/~lcoble/bible/water.html , loss of fur (cf. Mario's
ideas on salt & fur) etc.
> The trouble is we seem to simultaneously have traits which indicate fresh
water dependence and scars of a marine past too. That's one of the
attractions of the hybridisation idea for me. It is as if our marine traits
have been half bred out.
Well, that's perhaps an argument in favour of your hybridisation ideas. But
it isn't enough IMO. First seaside & later reterrestrialisation are the
minimal requirements IMO, IOW, riverside is unproven & superfluous as an
explanation, but a priori not impossible.
> > > I think he downplays the importance of fossil data
> > I don't. I only dowplay the importance of fossils for our ancestors.
Human anatomy & physiology & behaviour say a lot about our ancestry. Fossils
OTOH only say something on the fossils, not directly on our ancestors. And
since IMO most or all apiths were closer relatives of chimps or gorillas
than of people, they're not very relevant for Homo evolution.
> I can't argue with that Marc but what about early Homo? IMO seems to
indicate an African origin. And what about modern Homo sapiens? It seems to
me that the fossil and molecular data both back a second Out of Africa and
the replacement model.
Yes, not unlikely, but whether they came from Africa or not, IMO human
features are more important for reconstructing our evolution than fossils
are. If anything, the fossils only support our (comparative) scenario. (More
specifically, they suggest the semi-aquatic phase happened
begin-Pleistocene, when Homo dispersed along the Med. & Indian Ocean
shores.)
> > > - thus lessening the importance of the African hominoidae hypodigm and
overplays the idea that much of this evolution happenned on coastlines -
where all the fossils are conveniently covered by the seas
> > :-) Yes, but it's not my fault that sea levels changed a lot during
the Pleistocene.
> That might be true Marc but any model has to be backed up with data.
That's what I did: use the data there are & think are relevant. Seaside is
more likely than riverside.
> > > . We've had other run-ins too about minor points of my model. I didn't
like the experience. Like you, he can come across as being very
self-righteous and arrogant when you're arguing against him.
> > :-( I'm sorry, Algis, if that's your impression.
> You see, Marc, you dismiss people as idiots too easily.
I know they're no idiots. If I call them idiots, I want to get rid of them:
they only waste my time & bring nothing new. Extremely frustrating talking
to prejudiced people who think they know everything & in fact appear to be
uninformed & often not very smart.
> I understand your frustration when people disagree with you but the answer
is not to call them names and try to bully them into seeing that you're
right. That was the feeling I had when we disagreed about possibile
evolutionary explanation of the large infant brain. There might be no answer
but I think trying to find common ground is more likely to succeed than
pouring out insults.
Algis, I didn't see any progress in our "discussions" then. There was no
common ground, only useless repetitions.
> > IMO you don't have convincing arguments for your hybridisation ideas, bu
t I'm about the only one here I believe who openly supports your ideas on
partial sideways wading in early hominids.
> Mmm. The way I see it is that these are just ideas, Marc. I'd like to
depersonalise it. It's not so much that they are my ideas - Baird et al 2000
I AFAIK are the first to publish that humans might be the result of a
hybridisation of hominids. [Baird, Duncan M, Coleman, Joanna, Rosser,
Zoe H, Royle, Nicola J (2000). High levels of sequence polymorphism and
linkage disequilibrium at the telomere of 12q: Implications for Telomere
biology and Human Evolutions. American Journal of Human Genetics Vol:66
Pages:235-250] From abstract: "To explain the presence of a few diverged
haplotypes adjacent to the Xp/Yp and 12q telomeres, we propose a model that
involves the hybridisation of two archaic hominoid lineages ultimately
giving rise to modern Homo sapiens." I accept that the hybridisation
idea ia still very speculative but it does answer a few question and I've
not seen anything yet to contradict it.
Even if there was (some / a lot) hybridisation, Baird etc. don't say
anything on marine & freshwater.
> I don't know anyone who has ever suggested that Lucy waded using lateral
motion before but again, it's just an idea. It will stand or fall based on
the evidence. Thanks for your support on it but these things are nothing to
do with democracy. I'm sure you support it because it seems to fit the
facts, not because it was my idea. :-)
Yes, of course. In my Med.Hypotheses papers & in Roede etc.eds I compared
Lucy's broad pelvis to the broad bodies of beaver, hippo & platypus IIRC, I
agued that the flaring ilia, broad pelvis, long & horizontal femoral necks
were for better abduction, but I was thinking of swimming (cf.the above
freshwater mammals), not of lateral wading. Your lat.wading ideas nicely fit
our swamp feeding ideas (based on bipedality, paleo-environment, lowland
gorilla behaviour, isotopic data, microwear data). When different
independent lines of evidence point into the same direction, you have to
have a good reason to doubt it. Of course, lat.wading does in no way exclude
regular or occasional swimming, & vice versa.
> Similarly with the aquarboreal stuff. I support it because I think it fits
the facts best, not because it was your idea, Marc. Algis Kuliukas
Excellent.
Marc
Gerrit Hanenburg
>Yes. "350-600 mm" & "well-drained" are not "very dry".
For African latitudes with their high evaporation rates 350-600 mm is
not much. Combine this with well-drained soil (i.e. soil that doesn't
hold water very well) and you've got a semi-arid environment, not a
wetland.
Gerrit
Gerrit Hanenburg
>Thanks, Gerrit. I was about to search out this article
>and post it. How does it go.....biocenoses does not
>equal thanatocenoses. Hope I haven't garbled the
>spelling......
Wow, somebody slings the lingo :-)
Indeed, a fossil (death) assemblage is not an exact copy of the living
community.
Gerrit
Bob Keeter
> > "in tune" with you and your rhetoric as you would like! Cant say that I
> > see anything wrong with that, can you? 8-)))
>
> That's a bit unfair, Bob. Paleoanthropolgy is rife with academic
> inculturation. It's not difficult to imagine that undergraduates at
> university B lectured by professor B get taught a view of evolution
> that is rather more B-like than A-like. And, surprise, surprise when
> the brightest students go onto do their PhDs what are they most likely
> to study A or B?
In your particular case, I might agree that its being "unfair" to a degree;
from Marc, I think its only a pretty honest presentation of the facts. He
would much prefer divorcing himself from the facts, and expect "loyalty"
instead of logic and reason. Its that "cult" approach that he (and some
others in these debates) demands that shifts his views out of science and
into "loonery".
You yourself refer to how he tries to bully people into accepting his
"revelations" when his logic fails and he, himself, betrays the underlying
logic when he berates you for not "following his lead" when he has
supported your ideas. That would seem to be to go beyond the academic
"camps" that might form around certain "schools of thought". Seems to me
that it starts edging into what is more a "cult" of a leader and a bunch of
followers, "holding the faith" instead of thinking, stroking the ego of the
leader instead reasoning with the facts.
> When it comes to the AAH, precatically every university is in camp B
> and none in camp A. The only support of it at the moment is just a few
> disparate academics and enthusiasts. The only 'team' play for A is
> through newsgroups like this whereas B has a massive infrastructure of
> 'team playing' (let's call it by it's real name: peer pressure) going
> on every day. And now, when you think you have spotted a bit of it
> amongst AAH supporters you rush in to criticise.
And there is a term, one PARTICULAR word, for criticizing a thing and then
practicing a thing.. . .
One of the biggest "arguements" most of the fringe sciences advance is that
there is too much inertia (or even a conspiracy!) amongst conventional
science for accepting their theories. Sort of a "hey, look, THEY disagree
so it must be right!". To whimper because that same kind of monolythic
"unity" that they decry in conventional science just starts to sound like
its getting way too close to that word I refer to above. Hypocracy is a
very ugly thing. Shows a lot about a person.
> I hope you will now turn your attention to the huge peer pressure
> which has discouraged any PAs that are even in the mildest way
> sympathetic to the AAH from publicly saying so. Witness Tobias.
> That would be objective, Bob.
>
Are you saying that I NEVER confront the loons from the "savanna side"? You
have got to be kidding!
Loons are loons; sociopathic egotists are sociopathic egotists no matter
which 'school' they follow. I will gladly confront such no matter what
ideas they might be proposing. Do I need references? ;-)
The PROBLEM here is that every time someone gets a "wild hair" and decides
to debate the AAHe on a purely scientific basis, the discussion goes on for
a short period of time at a sane level and then descends into a "game" of
conveniently ignoring facts, selective "responses", calling the opposition
"idiots" and simple obnoxious ad hominem. If Im seening the pattern
correctly, the trigger is when the answers to the questions and the
responses to the challenges get "too hard" in a scientific venue and the
"supporter" simply must fall back on school-yard bullying in a futile
attempt to either change the line of discussion, discredit the disbeliever
or suck the opponent into the same "modus opperandi" whereby the initial
descent can be "justified" by claiming simple retaliation for the same
actions on the part of the opponent.
There is a timing problem with "who struck first" but then most people dont
apparently check the archives and if they do, might just choose to ignore
what they find! 8-)
Is there a good and healthy "inertia" in science for accepting new and
different "theories"? Of course! Would not you initiallly at least try to
impune some kind of hard evidence that totally discounted the ideas in your
thesis? The difference between a "pseudo-scientific cult" and science is
that science IS able to evolve, even if not as fast as some of us might
sometimes wish. A cult requires "support" instead of reason and very useful
skepticism.
Marc would apparently prefer "support". Says volumes.
Regards
bk
Bob Keeter
And here I was puzzling over 23-Across in the Globe crossword! 8-)
Regards
bk
Marc Verhaegen
"Gerrit Hanenburg" < G.Han...@inter.nl.nomail.net > wrote in message
news:a4csbv8iu6rovctgi...@4ax.com ...
> >Yes. "350-600 mm" & "well-drained" are not "very dry".
> For African latitudes with their high evaporation rates 350-600 mm is not
much. Combine this with well-drained soil (i.e. soil that doesn't hold water
very well) and you've got a semi-arid environment, not a wetland. Gerrit
Yes, the Dite sols suggest "rel.open low tree-shrub savanna" (JG Wynn 2000
"Paleosols, stable carbon isotopes, and paleoenvironmental interpretation of
Kanapoi, Northern Kenya" JHE 39:411-32). Other anamensis (Allia bay) are
found in wetter conditions. Leopards, the major predators of apiths, tend to
drage their prey to higher & drier places, sometimes more than 100 m from
the kill (CK Brain 1981 "The Hunters or the Hunted?" Univ.Chicago Press). It
may be that some apith species (esp. large E.African: Laetoli, Kanapoi,
Konso) lived in drier milieus than I thought, but Wynn's paper doesn't
contradict our view that apiths had aquarboreal ancestors.
Marc Verhaegen
http://www.onelist.com/community/AAT
http://allserv.rug.ac.be/~mvaneech/Verhaegen.html
Bob Keeter
>
> "Gerrit Hanenburg" < G.Han...@inter.nl.nomail.net > wrote in message
> news:a4csbv8iu6rovctgi...@4ax.com ...
>
> > >Yes. "350-600 mm" & "well-drained" are not "very dry".
>
> > For African latitudes with their high evaporation rates 350-600 mm is
not
> much. Combine this with well-drained soil (i.e. soil that doesn't hold
water
> very well) and you've got a semi-arid environment, not a wetland. Gerrit
>
> Yes, the Dite sols suggest "rel.open low tree-shrub savanna" (JG Wynn 2000
> "Paleosols, stable carbon isotopes, and paleoenvironmental interpretation
of
> Kanapoi, Northern Kenya" JHE 39:411-32).
Good! Accepting facts, particularly those supported by prolific "hard"
evidence is a very good step.
> Other anamensis (Allia bay) are found in wetter conditions.
Does this one strike a note. . .
". . . . . Non-human faunal remains from Allia Bay probably came from a few
different habitats and water transport is purported to have been vital to
the bone accumulation process [Coffing, et al, 1995]. The presence of both
closed-habitat and open-habitat species is indicative of this possibility.
Extensive weathering, a potential result of water transport, is apparent
upon some of the fossil specimens. Based upon those bones that showed few
signs of weathering, Coffing, et al [1995] suggested a transitional
environment, composed of elements of grassland, bushland and forest, at the
site. . . . . ."
http://www.archaeologyinfo.com/australopithecusanamensis.htm
So I would read this to say that there was a very wide mix of
"closed-habitat" and "open-habitat" bones to be found. This is completely
consistent with the current pattern of "savanna" flooding etc that we see
today. You find dead "savanna animals" and "forest animals" all collecting
in the same pools and eddys of the very seasonally flooded rivers. Could it
be that finding apith teeth and such "in the mix" at Allia Bay neither
either be fully supportive of a dry land creature nor a wet land creature?
If so, it means that Allia Bay finds have absolutely nothing to say in the
present arguement!
Would you not agree, Marc?
> Leopards, the major predators of apiths, tend to drage their prey to
> higher & drier places, sometimes more than 100 m from the kill (CK
> Brain 1981 "The Hunters or the Hunted?" Univ.Chicago Press).
Actually, would it not maybe be more correct to say that leopards ". . .tend
to drag their prey to the nearest tree (up to 100 m from the kill site). .
.". Doesnt matter if the kill is on the edge of a swamp or on the edge of a
very dry savanna, a leopard will apparently try to find a tree to get the
prey up and away from the hyenas and lions. Is that what you meant to say,
with no real inference of "wet to dry"? Again possibly not the most
pertinent point, one way or another?
> It may be that some apith species (esp. large E.African: Laetoli, Kanapoi,
> Konso) lived in drier milieus than I thought, but Wynn's paper doesn't
> contradict our view that apiths had aquarboreal ancestors.
>
You are absolutely correct. It does not say one thing about aquarboreal
ancestors, one way or another. It DOES suggest rather clearly that there is
no compelling reason to assume from any of these finds that the actual
creatures found were aquarboreal. What happen prior in the "family tree" is
still an unknown, at least based on this evidence, BUT nothing here suggests
that these hominids were aquaboreal!
So, we now have a temporal "line in the sand"! Pardon the pun. If there
were ever some sort of an aquarboreal ape, it would have had to exist some
considerable time previous to the datings of these finds, right?
Anything that might be "presumed" to indicate a transition from the trees to
the plains via the water that shows up after this date, is no longer
pertinent, right? Are there ANY arguments routinely offered up for the AAH
where the physical features appear AFTER the Allia Bay/ Kanapoi dates? If
so, would you perhaps consider ditching those lines of discussion as being
simply non-pertinent?
Regards
bk
Richard Wagler
Pauline M Ross wrote:
> On Fri, 09 May 2003 10:26:59 -0600, Richard Wagler <taxi...@shaw.ca>
> wrote:
>
> >>[Pauline] I'm quite happy to accept that there is not and never was a grand
> >> overarching Savanna Theory. But the 'savanna as major influence on
> >> human evolution' is *not* a strawman. It has influenced
> >> paleoanthropology, root and branch, for decades and it *still does*.
> >
> >[Rick] And why shouldn't it? A huge mass of evidence says early
> >hominids lived in svannah environments (propoerly defined).
>
> Would you define savannah for me, Rick? It's difficult to discuss a
> concept without knowing what you mean by it.
The critical factor in defining savannah environments is
the ground cover. In savannah environments it is grass,
In forests it is herbs. In semi-deserts and deserts it is
discontuous, widely-spaced or absent. The canopy coverage
- the amount of ground under trees - can be fairly large -
up to 50% in what are cnsidered savannah environments.
Grassy meadows in forests are not savannah - though the
savannah relics engulfed in the Congo forest are quite
interesting. That's my understanding of what is meant by
savannah environments. Treeless, grassy plains are certainly
savannah but they aren't the whole story.
>
>
> >The whole problem is that Morgan et al have taken the Dartian
> >position as some kind of orthodoxy [...] The standard AAT critique of
> >PA is absolute junk - a classic definition of a strawman.
>
> Now you're doing exactly what David was complaining of :-) What
> exactly is the "standard AAT critique of PA"?
The usual runup we get from Elaine. I'm sure you
are familiar with it. I don't throw Elaine in with
Crowley and McGinn and their intemperate rejection
of the whole discipline but it is pretty bad. Particualrly
her insistence that PA has no 'theories' concerning the
many questions that bedevil the field. Perhaps she simply
rejects the cautious way that science distinguises scenarios
and speculations from formal hypotheses and theories -esp
since her 'theory' is nothing more than speculative scenario
building.
>
>
> >>[Pauline] Of course there have been adjustments over the years, notably
> >> bipedalism has been pushed back into the trees and the definition of
> >> 'savanna' has expanded,
> >
> >[Rick] has it?
>
> Well, it seems to me that it has. I've quoted my preferred definition
> before (tropical grassland, scattered trees, dry season - from a very
> reputable source), but various people have defined it to include
> extensive trees and a lot of water.
See above
>
> >
> >>[Pauline] but the original idea of a hot, dry
> >> environment still informs a great deal of PA thinking. I have quoted
> >> one professional lamenting that researchers are still fixated on a
> >> Serengeti-type environment,
> >
> >[Rick] I read that article too. Not a bad piece. Too bad you only
> >take out of it what you want.
>
> Well, I take out of it lots of things, but Tappen's comments about the
> Serengeti are the only ones I have had occasion to quote to date.
>
> >Still there were very dry areas
> >in Pliocene Africa - Kanapoi comes to mind - and hominid
> >fossils have been found there. In any event the scavenging
> >studies done in dry savannahs kind of confirm the point that
> >a living was avaiable to any hominid who might have been
> >in these sorts of places were they of a mind to scavenge.
>
> Well, Tappen's findings and quotes from other studies kind of indicate
> that it would have been more a supplement than a living (although more
> likely in dry areas). But her study was fairly limited.
But the important thing about all these scavenging studies
is that carcasses are availible. If one had to guess one would
say that hyaenas, jackals, vultures etc etc would be on them
immediately. I guess that's why science is always investigating
the obvious - so often the commonsensical and obvious turns
out to be anything but....
>
> >
> >>[Pauline] and public-consumption human evolution
> >> still peddles that line - witness the recent BBC series 'Walking With
> >> Cavemen', which showed our ancestors trailing prey across what can
> >> only be described as desert,
> >
> >[Rick] If you remember these were erectus.
>
> Ergaster, actually.
>
> > The Acheulian archaeological
> >record shows that these folks inhabited arid areas along with
> >nearly everyplace else. The scenes involving a'piths were not
> >like this.
>
> No, the a'piths were shown in grassland with scattered acacia trees,
> or in denser woodland along rivers. Most of the rest were in dry, open
> areas, in some cases verging on desert. The Asian erectus were in a
> wetter environment, and the Neandethals were in snow, of course.
But a'piths *were* in a mosaic of environments. What's
wrong with depicting that? The LCA and the stem hominid
would, in all likelihood, be a forest dweller. That, as far as
I'm concerned, is the only hit the'savannah theory' has taken.
>
> >
> >>[Pauline] and that included the likes of Chris
> >> Stringer and Leslie Aiello in the credits.
> >
> >[Rick] So? What falsehood do you think was prmulgated
> >by this program?
>
> We are not adapted for and did not evolve in dry, near-desert
> conditions. In my opinion. Bipedalism in particular did not evolve in
> a dry, open habitat, and it is misleading to suggest that it did.
They did not suggest it, did they? In the truncated version
I saw their is no explicit discussion of the origins of bipedalism -
only that a'piths were bipeds and the significance of that.
As for not being adapted to dry, near desert conditions modern
human physiology accomodates quite well to them. The technology
needed to survive in northern latitudes is much more complex
than what is needed in the tropics - wet or dry. Why get
hung up on humans not being savannah *specialists*?
We aren't. Probably never were.
>
>
> I have to say, though, that the book accompanying the series (by John
> Lynch and Louise Barrett) is much more balanced.
>
> >Define 'savannah theory'
>
> Pass.
Oh, come on....It's the great bete noire of
'alternative' PA. You must have some notion
of what the term is supposed to signify
>
>
> >>[Pauline] And where I spot him saying something which I
> >> think is totally wrong, I *do* intervene.
> >
> >[Rick] Where? Do you, for example, simply accept Marc's assertion
> >that proboscis monkeys are the most bipedal of monkeys
> >even though he is completely unable to back this up? Have
> >you ever checked any of Marc's references? Or do you
> >simply accept his assurance that they are relevant and say what he
> >says they do? I have cheecked some of his references and
> >you should not accept any of them at face value.
>
> Well, I don't accept anything *anyone* says here at face value. Almost
> all the regulars on sap have an axe to grind, so everyone is quoting
> selectively, and pointing out evidence that supports their case, and
> not mentioning anything that doesn't.
Absolutely. But if you quote Tappen on the Serengeti
I trust you to accurately reflect what she said and that
what you quote does not run counter to her general
argument. Having read the article I know that you did.
I cannot - nor should any one else esp his would-be
allies - accord the same privilege to Marc. He simply
cannot be trusted. Sorry if this sounds like Marc bashing
but we had another example this very day.
>
>
> And I don't regard that as intellectual dishonesty *if* whenever
> anyone finds apparently contradictory evidence, they mull it over and
> research it and work out for themselves what it actually means. I do
> that, and I know Algis does, and Mario, and I expect Marc does too,
> but nobody sees it so you assume we are all just working on blind
> faith. Not so.
In the case of Marc and Algis their insistence that
Richmond and Strait argue for a'piths being knuckle-walkers
is a case in point. They consistently do this *without*
noting that R & S *do not* make that argument. Using
somebody's data for your own purposes is perfectly
acceptable but you *do not* cite them as supporting your
argument. This is dishonest and is exactly the sort of
shenanigan that will deny the AAT any hearing.
>
>
> As to the proboscis monkeys, I have no idea whether Marc is right, and
> no immediate way to find out. Since I don't have an informed comment
> to make, I say nothing. OK?
Your missing the point. It's not about proboscis monkeys. These
buggers may indeed be the most bipedal of monkeys. I certainly
don't know. The point is that Marc doesn't know either but
pushes it forward as an established point of science anyway.
This is consistent behaviour with him. That is what I will call
him on. I don't give a rat's ass whether proboscis monkeys
are never bipedal or bipedal 99 %of the time. Means nothing.
Similarly Algis on the basis of his zoo study of one population
of captive bonobos has taken to saying that apes in the wild
are 100% bipedal when wading. If he's going to carry these
sorts of deductive processes into the academic world he'd
better have a flame-retardant ass. He's gonna need it.
Hope that clears things up
Rick Wagler
Bob Keeter
your continuous ad hominem. Convincing me of the aquatic ape theory is
wasted effort even for a "cultist" approach; casting a very disparaging
light on your "theory" is of course your business (and you excell at that).
So. . . as a died in the wool disbeliever, I must cheer you on! Doing good
Marc, keep up the good work of diverting decent, intellectually honest and
reasoning people away from the anything connected with the dear old AAT!
GOOD JOB!
Regards
bk
Marc Verhaegen
> In the case of Marc and Algis their insistence that Richmond and Strait
argue for a'piths being knuckle-walkers is a case in point. They
consistently do this *without* noting that R & S *do not* make that
argument. Using somebody's data for your own purposes is perfectly
acceptable but you *do not* cite them as supporting your argument. This is
dishonest and is exactly the sort of shenanigan that will deny the AAT any
hearing.
Wagler, nobody doubts the PA data. But your short-sighted just-so
interpretations are ridiculous. Or dishonest. Try to think a little bit for
once. R&S say anamensis had some KWing features. That's the data. Their
interpreation is clearly wrong. KWers live today. KWing is derived. Apiths
were nearer the ancestral hominid condition. Humans had never KWing
ancestors. Okidoki, you idiot?
Marc Verhaegen
>
> > > > For the Xth time, our view is based mostly on comparative data, and
> > Kanapoi in no way contradicts this. Dishonest are those who say Kanapoi
> > suggests our ideas are wrong.
> >
> > > Marc, in your sad little eyes, anything that does ot SCREAM aquatic
ape
> is
> > dishonest. One wonders if you dont try to hard to make the evidence that
> > does exist scream a bit> too loud. Truth is not measured in dB's! 8-)
> > Regards
> >
> > The usual blabla. No contents. No regards.
> >
> Well, maybe its the "no regards" that you reap with your evasive answers
and
> your continuous ad hominem. Convincing me of the aquatic ape theory
I'm not trying to convince short-sighted people of anything.
Richard Wagler
Marc Verhaegen wrote:
Memo to Pauline Ross:
I rest my case.
Rick Wagler
Bob Keeter
Think that he could shoot for "No lo contendre"?
Regards
bk
Marc Verhaegen
> Think that he could shoot for "No lo contendre"?
bk, not only PA is a bit difficult for you, but Spanish apparently also.
Wovon man nicht sprechen kann, darueber muss man schweigen.
Pauline M Ross
wrote:
>>[Pauline] Would you define savannah for me, Rick? It's difficult to discuss a
>> concept without knowing what you mean by it.
>
>[Rick] The critical factor in defining savannah environments is
>the ground cover. In savannah environments it is grass,
>In forests it is herbs. In semi-deserts and deserts it is
>discontuous, widely-spaced or absent. The canopy coverage
>- the amount of ground under trees - can be fairly large -
>up to 50% in what are cnsidered savannah environments.
>Grassy meadows in forests are not savannah - though the
>savannah relics engulfed in the Congo forest are quite
>interesting. That's my understanding of what is meant by
>savannah environments. Treeless, grassy plains are certainly
>savannah but they aren't the whole story.
OK. You don't mention temperature or rainfall but I presume you regard
these as important defining features too (otherwise a large part of
Britain would be 'savannah' by this definition, and I can't believe
that is what you mean).
>>[Pauline] Now you're doing exactly what David was complaining of :-) What
>> exactly is the "standard AAT critique of PA"?
>
>[Rick]The usual runup we get from Elaine. I'm sure you
>are familiar with it.
OK, but I have no interest in discussing what other people may or may
not think.
>[Rick] But the important thing about all these scavenging studies
>is that carcasses are availible. If one had to guess one would
>say that hyaenas, jackals, vultures etc etc would be on them
>immediately. I guess that's why science is always investigating
>the obvious - so often the commonsensical and obvious turns
>out to be anything but....
Yes, although to repeat, Tappen's findings were rather tentative and
didn't suggest to me that hominids could make a living from it. More
the odd fortuitous bonus.
>
>But a'piths *were* in a mosaic of environments. What's
>wrong with depicting that? The LCA and the stem hominid
>would, in all likelihood, be a forest dweller. That, as far as
>I'm concerned, is the only hit the'savannah theory' has taken.
OK.
>>[Pauline] We are not adapted for and did not evolve in dry, near-desert
>> conditions. In my opinion. Bipedalism in particular did not evolve in
>> a dry, open habitat, and it is misleading to suggest that it did.
>
>[Rick] They [in 'Walking With Cavemen'] did not suggest it, did they? In the truncated version
>I saw their is no explicit discussion of the origins of bipedalism -
>only that a'piths were bipeds and the significance of that.
OK, the book is more explicit, and discusses the 'peering over long
grasses' theory and Peter Wheeler's thermoregulatory model, before
plumping for the energy-efficiency model (and the famous packet of
biscuits!). And all of it resulting from the drier, more open climate.
>As for not being adapted to dry, near desert conditions modern
>human physiology accomodates quite well to them. The technology
>needed to survive in northern latitudes is much more complex
>than what is needed in the tropics - wet or dry. Why get
>hung up on humans not being savannah *specialists*?
>We aren't. Probably never were.
OK.
>> >[Rick] Define 'savannah theory'
>>
>> [Pauline]Pass.
>
>[Rick] Oh, come on....It's the great bete noire of
>'alternative' PA. You must have some notion
>of what the term is supposed to signify
I've already said upthread that I don't think there is (or ever was) a
'savannah theory' as such - just an underlying idea that human
evolution was driven by the drier, more open environment of the
developing savannah.
>Absolutely. But if you quote Tappen on the Serengeti
>I trust you to accurately reflect what she said and that
>what you quote does not run counter to her general
>argument. Having read the article I know that you did.
Thank you.
>I cannot - nor should any one else esp his would-be
>allies - accord the same privilege to Marc. He simply
>cannot be trusted. Sorry if this sounds like Marc bashing
>but we had another example this very day.
Nevertheless, it was an accurate quote; Leakey et al *did* say that
there was a gallery forest and a large river at Kanapoi, and that was
the point Marc wanted to make to counter your comment that Kanapoi was
"very dry".
And I did look up the full quote, as Gerrit did and anyone with Google
could have done, but I don't think it substantially alters the
position. Kanapoi was dry and open, with wide gallery forest and a
large river, so everybody was right :-).
And it isn't my job to check up on Marc.
>In the case of Marc and Algis[...]This is dishonest and is exactly the sort of
>shenanigan that will deny the AAT any hearing.
It isn't my job to check up on Marc *or* Algis - take it up with them.
>>[Pauline] As to the proboscis monkeys, I have no idea whether Marc is right, and
>> no immediate way to find out. Since I don't have an informed comment
>> to make, I say nothing. OK?
>
>[Rick] Your missing the point. It's not about proboscis monkeys. These
>buggers may indeed be the most bipedal of monkeys. I certainly
>don't know. The point is that Marc doesn't know either but
>pushes it forward as an established point of science anyway.
>This is consistent behaviour with him. That is what I will call
>him on.
Then call him on it. Or better still, do the research and find out.
But, please - leave Marc out of a discussion with me, OK?
--
Pauline Ross
Algis Kuliukas
> In the case of Marc and Algis their insistence that
> Richmond and Strait argue for a'piths being knuckle-walkers
> is a case in point. They consistently do this *without*
> noting that R & S *do not* make that argument. Using
> somebody's data for your own purposes is perfectly
> acceptable but you *do not* cite them as supporting your
> argument. This is dishonest and is exactly the sort of
> shenanigan that will deny the AAT any hearing.
What?
So if somebody does research and produce a body of data and decides to
publish a paper interpretting that data one way, others cannot use the
same data but interpret it in another way, later? Nonesense.
That is more or less exactly what Rodman & McHenry (1980) did with the
Taylor and Rowtree (1973) data. They originally interpreted to
conclude that energetic efficiency could not be used as an argument in
favour of bipedalism, R & McH re-interpreted it to mean that it
couldn't be used againat the energy efficiency argument. So, were they
dishonest? Somehow, I think that you'll come up with a formula of
words that lets them off the hook but attempts to keep me firmly on it
but then, perhaps - you never know - maybe you could show some
objectivity and concede that you overstretched your argument.
There are countless examples of this kind of thing in the literature.
I know Richmond & Strait's paper was careful not to propose anything
so controversial as the idea that A'piths were knuckle-walkers. I
never, for one moment, pretended that they did. In fact I also noted
the Aeillo & Collard article in the same edition of Nature which made
the same point that you do. So, who is being dishonest here?
But ;let's get to the issue, seeing you raised it. Why didn't they
suggest that knuckle-walking traits indicated knuckle-walking? It
would be a parsimonious view after all. Perhaps they concluded that
the peer pressure would be too great to make such a suggestion perhaps
it was because the other traits in a. afarensis indicated a bipedal
posture and the two couldn't be reconcilled. As Aiello & Collard
pointed out - how could this animal be a terrestrial biped *and* also
be a knuckle-walker? Of course, neither Richmond or Strai or Aiello &
Collard considered the possibility that A. afaransis might have waded,
thus solving the riddle.
The fact is that the data they did publish does show analogous traits
in A'piths to those in Pan/Gorilla for knuckle-walking. The idea that
this was a vestigial trait for one-million years from an ancestral
knuckle-walker is the only notion that can possible explain it other
than, of course, the crazy idea that they actually knuckle-walked.
As there is a great deal of evidence to show that bones are very
plastic in one life time (witness tennis players cortical thickening
for one simple example) it seems farcically inconceivable to me that
such exposed bony structures as notches on the distal radii would
remain, without any function, for one million years. What do you
think?
Why don't you focus on the issues and data instead of pouring slur on
those who happen to hold a different view to yourself?
Algis Kuliukas
Bob Keeter
PA is difficult but not impossible, but I can tell the difference between
poor Latin (I had inserted an extra space) and worse Spanish.
Nolo Contendre Latin for "I will not defend it." A statement in a
criminal trial where the defendant declines to refute the evidence presented
but agrees to the charges presented in the complaint. It cannot be used as
an admission in other proceedings.
Besser, um schweigsam und ist gedacht ein Narr zu sein, als um laut zu sein
und den Punkt beweist. Have a nice vacation!
Jason Eshleman
>Richard Wagler <taxi...@shaw.ca> wrote in message news:<3EBE7C50...@shaw.ca>...
>
>> In the case of Marc and Algis their insistence that
>> Richmond and Strait argue for a'piths being knuckle-walkers
>> is a case in point. They consistently do this *without*
>> noting that R & S *do not* make that argument. Using
>> somebody's data for your own purposes is perfectly
>> acceptable but you *do not* cite them as supporting your
>> argument. This is dishonest and is exactly the sort of
>> shenanigan that will deny the AAT any hearing.
>
>What?
>
>So if somebody does research and produce a body of data and decides to
>publish a paper interpretting that data one way, others cannot use the
>same data but interpret it in another way, later? Nonesense.
You can interpret the data any way you want, but if you're going to
interpret only *some* of the data, someone's going to call you on it every
single time. What you've decided to do is interpret a particular tiny
piece, that there's a characteristic found in A.anamensis and A.afarensis
that's also found in knucklewalkers and conclude that these guys could be
early on on a trajectory towards knucklewalking. That's an interpretation
that takes the characteristic *entirely* out of context. The trait is a
minor component of knuckle walking which, on it's own, doesn't have a
functionality. It's part of a complex of traits that on its own is rather
worthless. You've dismissed this, saying that maybe they were just
"stablizing themselves" getting in and out of the water, but there's no
reason *at all* to believe that this trait would functionally develop from
such activity and significant reason to believe that these animals weren't
using their forelimbs for *any* signficant weight bearing.
You're not simply re-interpretinng data. You're wholesale taking things
out of context to support something that, in context, has no support.
It may not be dishonest, but it's not science either. To make the case
you do, you've got to explain why their explanation (a vestigial holdover)
is less likely than another explanation (and your own incredulity isn't
sufficient--I'm aware that you have a hard time believing it) and why you
can ignore the context of their pronouncement.
[snip]
>The fact is that the data they did publish does show analogous traits
>in A'piths to those in Pan/Gorilla for knuckle-walking. The idea that
>this was a vestigial trait for one-million years from an ancestral
>knuckle-walker is the only notion that can possible explain it other
>than, of course, the crazy idea that they actually knuckle-walked.
In the context of what makes a knucklewalker a knucklewalker, it being a
vestigial holdover makes more sense.
>As there is a great deal of evidence to show that bones are very
>plastic in one life time (witness tennis players cortical thickening
>for one simple example) it seems farcically inconceivable to me that
>such exposed bony structures as notches on the distal radii would
>remain, without any function, for one million years. What do you
>think?
I think you don't know much about functional anatomy, have zero idea how
the trait functions, zero idea how it forms (if it is plastic, if it is
under tighter genetic control) and are making things up to suit your
purpose, all the while ignoring what is known about knucklewalkers.
>Why don't you focus on the issues and data instead of pouring slur on
>those who happen to hold a different view to yourself?
Why don't you make a better argument rather than raising personal
incredulity as your foremost line of defense against evidence otherwise?
Ross Macfarlane
> Richard Wagler <taxi...@shaw.ca> wrote in message news:<3EBE7C50...@shaw.ca>...
>
> > In the case of Marc and Algis their insistence that
> > Richmond and Strait argue for a'piths being knuckle-walkers
> > is a case in point. They consistently do this *without*
> > noting that R & S *do not* make that argument. Using
> > somebody's data for your own purposes is perfectly
> > acceptable but you *do not* cite them as supporting your
> > argument. This is dishonest and is exactly the sort of
> > shenanigan that will deny the AAT any hearing.
>
> What?
>
> So if somebody does research and produce a body of data and decides to
> publish a paper interpretting that data one way, others cannot use the
> same data but interpret it in another way, later? Nonesense.
Algis, for heaven's sake take a deep breath & reread what Rick wrote.
The gist of your post is exactly what he posted. He said that "using
somebody's data for your own purposes is perfectly acceptable". What
he takes issue with is that in doing so, you should not imply that
their interpretation of the data is the same as yours - in fact, it
should be explicit that it it is your interpretation of their data,
and not theirs.
Marc consistently cites reams of scientific references in support of
his scenario, and never once mentions that they are referenced based
on his interpretation of the author's paper. This lays him open to a
charge of intellectual dishonesty, especially when he is using the
refs with a lay audience, such as SAP.
Literature searches are of course a mainstay of Marc's scenario, as he
apparently undertakes no original research of his own. Nothing wrong
with that per se, but very few of his sources, as you would know,
would agree with his interpretations of their data as it relates to
hominid evolution...
Ross Macfarlane
Algis Kuliukas
> al...@RiverApes.com (Algis Kuliukas) wrote in message news:<77a70442.03051...@posting.google.com>...
> > Richard Wagler <taxi...@shaw.ca> wrote in message news:<3EBE7C50...@shaw.ca>...
> >
> > > In the case of Marc and Algis their insistence that
> > > Richmond and Strait argue for a'piths being knuckle-walkers
> > > is a case in point. They consistently do this *without*
> > > noting that R & S *do not* make that argument. Using
> > > somebody's data for your own purposes is perfectly
> > > acceptable but you *do not* cite them as supporting your
> > > argument. This is dishonest and is exactly the sort of
> > > shenanigan that will deny the AAT any hearing.
> >
> > What?
> >
> > So if somebody does research and produce a body of data and decides to
> > publish a paper interpretting that data one way, others cannot use the
> > same data but interpret it in another way, later? Nonesense.
>
> Algis, for heaven's sake take a deep breath & reread what Rick wrote.
> The gist of your post is exactly what he posted. He said that "using
> somebody's data for your own purposes is perfectly acceptable". What
> he takes issue with is that in doing so, you should not imply that
> their interpretation of the data is the same as yours - in fact, it
> should be explicit that it it is your interpretation of their data,
> and not theirs.
But, Ross, I never did that. You should re-read what I wrote instead
of snipping it out.
"I know Richmond & Strait's paper was careful not to propose anything
so controversial as the idea that A'piths were knuckle-walkers. I
never, for one moment, pretended that they did. In fact I also noted
the Aeillo & Collard article in the same edition of Nature which made
the same point that you do. So, who is being dishonest here?"
> Marc consistently cites reams of scientific references in support of
> his scenario, and never once mentions that they are referenced based
> on his interpretation of the author's paper. This lays him open to a
> charge of intellectual dishonesty, especially when he is using the
> refs with a lay audience, such as SAP.
Better to cite scientific references that offer data (or at least
quotations) that support his scenario than not to do so. If he did
that, you'd just criticse him for something else. Of course his
citations are selective but what do you expect there? Considering the
body of opinion is stacked against the AAH, I think Marc's efforts to
quote from recognised papers is rather admirable. It seems to me that
Marc just can't with with you guys.
> Literature searches are of course a mainstay of Marc's scenario, as he
> apparently undertakes no original research of his own. Nothing wrong
> with that per se, but very few of his sources, as you would know,
> would agree with his interpretations of their data as it relates to
> hominid evolution...
So what?
Algis Kuliukas
Algis Kuliukas
> You can interpret the data any way you want, but if you're going to
> interpret only *some* of the data, someone's going to call you on it every
> single time. What you've decided to do is interpret a particular tiny
> piece, that there's a characteristic found in A.anamensis and A.afarensis
> that's also found in knucklewalkers and conclude that these guys could be
> early on on a trajectory towards knucklewalking. That's an interpretation
> that takes the characteristic *entirely* out of context.
But, Jason, the 'context' you assume here is terrestrial bipedalism.
In that 'context' of course it wouldn't make sense.
> The trait is a minor component of knuckle walking which, on it's own,
> doesn't have a functionality. It's part of a complex of traits that on its
> own is rather worthless.
If most of the body weight was not bearing down on the forarms I can't
see why it'd be worthless to stabilise the wrists for support.
> You've dismissed this, saying that maybe they were just
> "stablizing themselves" getting in and out of the water, but there's no
> reason *at all* to believe that this trait would functionally develop from
> such activity and significant reason to believe that these animals weren't
> using their forelimbs for *any* signficant weight bearing.
Well how do you think knuckle-walking began? I think it makes most
sense in a move from upright posture (perhaps brachiating, perhaps
wading) to quadrupedal. Knuckle-walking must have evolved somehow.
With these traits coming in somehow, perhaps some before others. How
do you see that scenario panning out, and why, specifically, do you
discount wading as a possible precursor?
> You're not simply re-interpretinng data. You're wholesale taking things
> out of context to support something that, in context, has no support.
Wading has lots of support. Extant apes are pretty much 100% bipedal
in water and so it is likely that a'piths would be too - and their
paleohabitats seem to have been predominantly gallery
forest/riverside/lakeside niches - which is also supportive of the
model.
The only 'context' you refer to is your terrestrial bipedal assumption
which might just be wrong. The lack of features for weight bearing on
the upper arm are easily explained as evidence of an early
evolutionary form of knuckle-walking from a wading/brachiating
precursor.
> It may not be dishonest, but it's not science either. To make the case
> you do, you've got to explain why their explanation (a vestigial holdover)
> is less likely than another explanation (and your own incredulity isn't
> sufficient--I'm aware that you have a hard time believing it) and why you
> can ignore the context of their pronouncement.
I tried. Plasticity in bone is such that even in one lifetime bone
grows to fit the stresses and strains being placed upon it during the
animal's development. The idea that a bony notch on such a vitally
important part of the body as the wrist would merely have remained
there as a ghost from a knuckle-walking past for one million years is
inconsistent with that fact.
> [snip]
> >The fact is that the data they did publish does show analogous traits
> >in A'piths to those in Pan/Gorilla for knuckle-walking. The idea that
> >this was a vestigial trait for one-million years from an ancestral
> >knuckle-walker is the only notion that can possible explain it other
> >than, of course, the crazy idea that they actually knuckle-walked.
>
> In the context of what makes a knucklewalker a knucklewalker, it being a
> vestigial holdover makes more sense.
In the context that the alternative explanation was an early
knuckle-walker I think the chance of it being a vestigial holdover is
farcically unlikely.
What evidence is there, in any case, that any hominoid knuckle-walked
before Lucy did? If you can show me some fossil evidence for an early
knuckle-walker I'd be more convinced but I don't think there is any.
Put in that context, your assumption that it was vestigial is contrary
to any fossil evidence and just a convenience to fit your model.
> >As there is a great deal of evidence to show that bones are very
> >plastic in one life time (witness tennis players cortical thickening
> >for one simple example) it seems farcically inconceivable to me that
> >such exposed bony structures as notches on the distal radii would
> >remain, without any function, for one million years. What do you
> >think?
>
> I think you don't know much about functional anatomy, have zero idea how
> the trait functions, zero idea how it forms (if it is plastic, if it is
> under tighter genetic control) and are making things up to suit your
> purpose, all the while ignoring what is known about knucklewalkers.
Oh wonderful. The ex cathedra (I know best) argument.
I read the Richmond and Strait article which made the function of the
notches in Pan/Gorilla fairly clear. I've been reading up about bone
plasticity and development and have been impressed with how plastic
they are. Charles Oxnard told me that in an experiment with rats, bone
morphology was drastically changed simply by the denervation of
muscle, even quite late in life.
Considering that there's no fossil evidence for a knuckle-walking
ancestor of Lucy I think it is you who is making things up to suit
your story line.
> >Why don't you focus on the issues and data instead of pouring slur on
> >those who happen to hold a different view to yourself?
>
> Why don't you make a better argument rather than raising personal
> incredulity as your foremost line of defense against evidence otherwise?
I agree that personal incredulity is no good. The evidence for bone
plasticity and lack of a putative knuckle-walking ancestor of
australopithecus, however, is.
Algis Kuliukas
Richard Wagler
Algis Kuliukas wrote:
> Richard Wagler <taxi...@shaw.ca> wrote in message news:<3EBE7C50...@shaw.ca>...
>
> > In the case of Marc and Algis their insistence that
> > Richmond and Strait argue for a'piths being knuckle-walkers
> > is a case in point. They consistently do this *without*
> > noting that R & S *do not* make that argument. Using
> > somebody's data for your own purposes is perfectly
> > acceptable but you *do not* cite them as supporting your
> > argument. This is dishonest and is exactly the sort of
> > shenanigan that will deny the AAT any hearing.
>
> What?
>
> So if somebody does research and produce a body of data and decides to
> publish a paper interpretting that data one way, others cannot use the
> same data but interpret it in another way, later? Nonesense.
I suggested this???
>
>
> That is more or less exactly what Rodman & McHenry (1980) did with the
> Taylor and Rowtree (1973) data. They originally interpreted to
> conclude that energetic efficiency could not be used as an argument in
> favour of bipedalism, R & McH re-interpreted it to mean that it
> couldn't be used againat the energy efficiency argument. So, were they
> dishonest? Somehow, I think that you'll come up with a formula of
> words that lets them off the hook but attempts to keep me firmly on it
> but then, perhaps - you never know - maybe you could show some
> objectivity and concede that you overstretched your argument.
Nonsense. Did R & M ever suggest that T & R supported
their position. Please get clear in your head what proper
citation is all about. You are going to have to understand this.
>
>
> There are countless examples of this kind of thing in the literature.
>
> I know Richmond & Strait's paper was careful not to propose anything
> so controversial as the idea that A'piths were knuckle-walkers. I
> never, for one moment, pretended that they did. In fact I also noted
> the Aeillo & Collard article in the same edition of Nature which made
> the same point that you do. So, who is being dishonest here?
You are. You are claiming, on no evidence of any sort, that
R & S are 'careful' not to propose a controversial interpretation
directly implying that the explanation for these traits that they
present are not their true opinions. This is ridiculous. You have
utterly no reason to accuse R & S of duplicity.
>
>
> But ;let's get to the issue, seeing you raised it. Why didn't they
> suggest that knuckle-walking traits indicated knuckle-walking?
So you refuse to understand that a suite of features is
indicative of kw. Ostriches have wings. Do ostriches
fly? Why not and how, from an anatomical point of
view, can you tell? Or do you think the anatomy of an
ostrich is identical re flight compared to an eagle? Maybe
you do....
> It
> would be a parsimonious view after all. Perhaps they concluded that
> the peer pressure would be too great to make such a suggestion perhaps
> it was because the other traits in a. afarensis indicated a bipedal
> posture and the two couldn't be reconcilled.
Perhaps they believe what they wrote. Absent any evidence
to the contrary simple courtesy and professional competence
make this the null position. Your ascription of darker motives
to R & S is outrageous
> As Aiello & Collard
> pointed out - how could this animal be a terrestrial biped *and* also
> be a knuckle-walker? Of course, neither Richmond or Strai or Aiello &
> Collard considered the possibility that A. afaransis might have waded,
> thus solving the riddle.
Yeah, right.....
>
>
> The fact is that the data they did publish does show analogous traits
> in A'piths to those in Pan/Gorilla for knuckle-walking. The idea that
> this was a vestigial trait for one-million years from an ancestral
> knuckle-walker is the only notion that can possible explain it other
> than, of course, the crazy idea that they actually knuckle-walked.
So you don't understand what vestigial traits are either...
>
>
> As there is a great deal of evidence to show that bones are very
> plastic in one life time (witness tennis players cortical thickening
> for one simple example) it seems farcically inconceivable to me that
> such exposed bony structures as notches on the distal radii would
> remain, without any function, for one million years. What do you
> think?
I think things atrophy rather quickly then hang around
for a long time. You can't take bone platicity to absurd
lengths. Why do you think an ostrich has wings?
>
>
> Why don't you focus on the issues and data instead of pouring slur on
> those who happen to hold a different view to yourself?
The only slur being tossed out is your's against R & S.
Your reply amply demonstrates the truth of my original
statement. There are some rather basic things regarding
honour, respect, and common human decency with regard
to others in the field that you are going to have to learn
if you plan to pursue this academically. Your position
in this post is completely unsupportable and dishonourable.
Rick Wagler
Jason Eshleman
>j...@vidi.ucdavis.edu (Jason Eshleman) wrote in message
>
>> You can interpret the data any way you want, but if you're going to
>> interpret only *some* of the data, someone's going to call you on it every
>> single time. What you've decided to do is interpret a particular tiny
>> piece, that there's a characteristic found in A.anamensis and A.afarensis
>> that's also found in knucklewalkers and conclude that these guys could be
>> early on on a trajectory towards knucklewalking. That's an interpretation
>> that takes the characteristic *entirely* out of context.
>
>But, Jason, the 'context' you assume here is terrestrial bipedalism.
>In that 'context' of course it wouldn't make sense.
No, you're wrong Algis, as the context is that animals that use their
forelimbs for support show obvious signs of this. I'm not sure if it's
developmental or genetic or some likely combination, but if you support
weight you show structures in the forelimb that indicate this. They
aren't subtle either. This is *real* comparative anatomy.
The context you seem to be favoring is one where we've got a knucklewalker
who doesn't knucklewalk. You've got some really deranged notion of how
this particular trait stabilizes the critter getting out of the water, but
does so without any weight bearing. We have *never* seen this. Critters
that use their forelimbs for support show obvious signs of it.
A.afarensis doesn't show these signs, nor did A.anamensis. The notch at
the distal end of the radii isn't one of these signs. It does not
function to stabilize the critter for knuckle walking *unless* it is
supporting its weight on the forelimbs. Yet there's no signs the arms
were designed for this, not in the water, not on land, not anywhere.
>
>> The trait is a minor component of knuckle walking which, on it's own,
>> doesn't have a functionality. It's part of a complex of traits that on its
>> own is rather worthless.
>
>If most of the body weight was not bearing down on the forarms I can't
>see why it'd be worthless to stabilise the wrists for support.
How again are you proposing this? I'm honestly perplexed. You're having
them just sort of lightly drag their arms just for a few seconds or
something and this is enough to get a notch but no other signs that they
used their arms for any support at all? And this makes more
sense because they were already bipedal in the water? ROTHLMMFAO!
>> You've dismissed this, saying that maybe they were just
>> "stablizing themselves" getting in and out of the water, but there's no
>> reason *at all* to believe that this trait would functionally develop from
>> such activity and significant reason to believe that these animals weren't
>> using their forelimbs for *any* signficant weight bearing.
>
>Well how do you think knuckle-walking began? I think it makes most
>sense in a move from upright posture (perhaps brachiating, perhaps
>wading) to quadrupedal. Knuckle-walking must have evolved somehow.
>With these traits coming in somehow, perhaps some before others. How
>do you see that scenario panning out, and why, specifically, do you
>discount wading as a possible precursor?
All solid indications are that we and the knucklewalkers share an arboreal
brachiating past. We've got all sorts of vestigial holdovers from this,
though it happened many millions of years ago. We've got wide torsos,
elongated clavicals, dorsally placed scapulae, a wide range of movement in
the shoulder and elbow and wrist, all of which we share with extant apes.
These are all notable signs of a brachiator. Brachiators have a rather
upright posture. IF one becomes large and starts using its forelimbs for
support, knucklewalking is a means of compromise since a baboon like
quadrupedalism has been more or less ruled out by the preadaptations from
brachiation.
I don't know how knucklewalking began, but I'm pretty damn sure that your
scenario doesn't flow. You're so hell-bent on making the environmental
stressors easy that you all but take them away.
We do know that *ever* animal that regularly supports itself shows
particular signs. We do know that A.afarensis and A.anamensis do not show
these signs.
Yet you ingore all this, favoring a mode of movement totally unknown, with
just a little bit of weight bearing (speculation- you have no evidence of
this) for only a little bit of time, and from this you speculate
(entirely-again you have no evidence) that this would result in the
notched distal radii but not any of the features found in anything that
uses its forlimbs for weight bearing activity.
Do you really not understand why this all sounds so absurd? Why several
speculative unknowns (probably unknowable) that may or may not even if
true result in the pattern you detail, seem significantly less probably
than the notches being vestigial.
Vestigial traits exist, your incredulity that these could be vestigial
notwithstanding. Your incredulity is that this piece of the body is so
"exposed" that it couldn't have lasted for a million plus years. That's
not science. That's merely your opinion, based on nothing more than your
opinion, and running counter to the evidence that many so significantly
"exposed" traits (like the form of our shoulder--a vestigial holdover from
a brachiator), like a clavical, no longer necessarily so long in humans
that, as a function of being so long, becomes the most oft broken bone in
the body.)
>> You're not simply re-interpretinng data. You're wholesale taking things
>> out of context to support something that, in context, has no support.
>Wading has lots of support. Extant apes are pretty much 100% bipedal
>in water and so it is likely that a'piths would be too - and their
>paleohabitats seem to have been predominantly gallery
>forest/riverside/lakeside niches - which is also supportive of the
>model.
Now waitaminute! You're saing these creatures are 100% bipedal when
wading. Ergo, no reason for support from the wrist. It must be then that
they don't need the support from the wrist. It must then be whilst they
are getting out of the water or have reached land that (and I apoligize
for yelling, but you really don't seem to pick up on this poing) BY YOUR
OWN SCENARIO THEY WOULD USE THEIR WRISTS. At this point, the support of
the water is gone.
Or are you having them begin to knuckle walk in water deep enough to get
some support (e.g. water up to their torso--less deep and they don't get
the support) in contradiction to your "apes wade, even in water that's not
so deep as to require it" pronouncement? If you're not here contradicting
yourself, you've got to explain how using the arm for support isn't
similarly using it to bear weight.
>The only 'context' you refer to is your terrestrial bipedal assumption
>which might just be wrong. The lack of features for weight bearing on
>the upper arm are easily explained as evidence of an early
>evolutionary form of knuckle-walking from a wading/brachiating
>precursor.
No, Algis. The context is weight bearing. That's a context that's
totally independent of how much water these guys were in. If they need to
stabilize their bodies with their forelimbs, they're loading the
forelimbs. Animals that do this show signs of it. A.anamensis and
A.afarensis do not show these signs. It's an unfortunate fact for your
scenario. You want to be objective? Please admit this and stop parading
around a fantasy.
>> It may not be dishonest, but it's not science either. To make the case
>> you do, you've got to explain why their explanation (a vestigial holdover)
>> is less likely than another explanation (and your own incredulity isn't
>> sufficient--I'm aware that you have a hard time believing it) and why you
>> can ignore the context of their pronouncement.
>I tried. Plasticity in bone is such that even in one lifetime bone
>grows to fit the stresses and strains being placed upon it during the
>animal's development. The idea that a bony notch on such a vitally
>important part of the body as the wrist would merely have remained
>there as a ghost from a knuckle-walking past for one million years is
>inconsistent with that fact.
Your last statement is not at all substantiated. Please do take note of
that. That the notch is inconsistent with being vestigial is *ENTIRELY*
your assertion and nothing more. What again, save incredulity, is your
argument that the trait cannot be vestigial? Why again, other than your
pronouncement as such, is this region of the wrist so vital? What exactly
does the notch prevent that would suggest that it would disappear so
quickly if not under selection?
>> [snip]
>> >The fact is that the data they did publish does show analogous traits
>> >in A'piths to those in Pan/Gorilla for knuckle-walking. The idea that
>> >this was a vestigial trait for one-million years from an ancestral
>> >knuckle-walker is the only notion that can possible explain it other
>> >than, of course, the crazy idea that they actually knuckle-walked.
>>
>> In the context of what makes a knucklewalker a knucklewalker, it being a
>> vestigial holdover makes more sense.
>
>In the context that the alternative explanation was an early
>knuckle-walker I think the chance of it being a vestigial holdover is
>farcically unlikely.
And again, this is substantiated only by what you think and not any actual
data, comparative, experimental, similative, or otherwise. It's a product
again only of your incredulity which runs counter to other examples of
vestigial holdovers which persist for much longer. Additionally, you
*aren't* really proposing an alternative. You're providing a story, ripe
with internal inconsistencies, whereby wading magically produces a
situation that produces the notch, preadapting for knucklewalking, but
produces no other features.
To further complicate your scenario, you are either putting
A.afarensis in a clade ancestral to the extant knucklewalkers,
or instituting an additional instance of the evolution of knucklewalking
independent of that seen in the extant apes. Both scenarios are
exceptionally abusive to parsimony. If the former is the case, you've got
ridiculous levels of homoplasy in dental characteristics coupled with
radical (and seemingly untraceable) reversals in pelvis and hindlimb
morphology in Gorilla and Pan.
Do you really not see the problems?
>What evidence is there, in any case, that any hominoid knuckle-walked
>before Lucy did? If you can show me some fossil evidence for an early
>knuckle-walker I'd be more convinced but I don't think there is any.
>Put in that context, your assumption that it was vestigial is contrary
>to any fossil evidence and just a convenience to fit your model.
There's no direct evidence that anything knucklewalked prior to the extant
apes, but there's some evidence that we fall out in morphological analysis
in a clade with the extant knucklewalkers. The true independence of
character inheritance is difficult to untangle so this might be a product
of measuring features which are not independent and not entirely tied to
knucklewalking, but it's suggestive that we had a knucklewalking ancestor.
Please again note: you use the line "[w]hat evidence is there, in any
case, that any hominoid knuckle-walked before Lucy did?" This could
easily be construed as suggesting that Lucy knuckle-walked. Again, just
in case this is what you're suggesting, that's HIGHLY unlikely as there's
considerable evidence that A.afarensis did not have forelimbs in any way
consistent with knucklewalking.
You further seem to be abusing the word "contrary" as in "[p]ut in that
context, your assumption that it was vestigial is contrary to any fossil
evidence and just a convenience to fit your model." That, Algis, is
simply false. There's nothing contrary to the fossil evidence that says
Lucy had an knucklewalking ancestor. The absense of evidence is not
contrary. Again, I'm not saying this out of "convenience" to
"my" model.
>> >As there is a great deal of evidence to show that bones are very
>> >plastic in one life time (witness tennis players cortical thickening
>> >for one simple example) it seems farcically inconceivable to me that
>> >such exposed bony structures as notches on the distal radii would
>> >remain, without any function, for one million years. What do you
>> >think?
>>
>> I think you don't know much about functional anatomy, have zero idea how
>> the trait functions, zero idea how it forms (if it is plastic, if it is
>> under tighter genetic control) and are making things up to suit your
>> purpose, all the while ignoring what is known about knucklewalkers.
>
>Oh wonderful. The ex cathedra (I know best) argument.
I'd stop using it if you'd stop showing me that you know less. But
actually, the argument wasn't that I know best, it's that you've
demonstrated that you know so little (yet seem prepared to make claims
based on what little you know and what you speculate beyond what you know,
even when the speculation so often runs contrary to observations).
>I read the Richmond and Strait article which made the function of the
>notches in Pan/Gorilla fairly clear. I've been reading up about bone
>plasticity and development and have been impressed with how plastic
>they are. Charles Oxnard told me that in an experiment with rats, bone
>morphology was drastically changed simply by the denervation of
>muscle, even quite late in life.
>
>Considering that there's no fossil evidence for a knuckle-walking
>ancestor of Lucy I think it is you who is making things up to suit
>your story line.
Think what you want. You're still wrong.
>> >Why don't you focus on the issues and data instead of pouring slur on
>> >those who happen to hold a different view to yourself?
>>
>> Why don't you make a better argument rather than raising personal
>> incredulity as your foremost line of defense against evidence otherwise?
>
>I agree that personal incredulity is no good. The evidence for bone
>plasticity and lack of a putative knuckle-walking ancestor of
>australopithecus, however, is.
Is what? Is evidence that we've got big breaks in the fossil record?
What again are you saying about bone plasticity? You're tossing out these
concepts, but you're not putting them together. In short, you're not
making sense.
Algis Kuliukas
> Algis Kuliukas <al...@RiverApes.com> wrote:
> >j...@vidi.ucdavis.edu (Jason Eshleman) wrote in message
By the way, sorry I accused you of snipping the k-w-ing bits from the
other post. I'd forgotten about this one.
> >> You can interpret the data any way you want, but if you're going to
> >> interpret only *some* of the data, someone's going to call you on it every
> >> single time. What you've decided to do is interpret a particular tiny
> >> piece, that there's a characteristic found in A.anamensis and A.afarensis
> >> that's also found in knucklewalkers and conclude that these guys could be
> >> early on on a trajectory towards knucklewalking. That's an interpretation
> >> that takes the characteristic *entirely* out of context.
> >
> >But, Jason, the 'context' you assume here is terrestrial bipedalism.
> >In that 'context' of course it wouldn't make sense.
>
> No, you're wrong Algis, as the context is that animals that use their
> forelimbs for support show obvious signs of this. I'm not sure if it's
> developmental or genetic or some likely combination, but if you support
> weight you show structures in the forelimb that indicate this. They
> aren't subtle either. This is *real* comparative anatomy.
>
> The context you seem to be favoring is one where we've got a knucklewalker
> who doesn't knucklewalk. You've got some really deranged notion of how
> this particular trait stabilizes the critter getting out of the water, but
> does so without any weight bearing. We have *never* seen this. Critters
> that use their forelimbs for support show obvious signs of it.
> A.afarensis doesn't show these signs, nor did A.anamensis. The notch at
> the distal end of the radii isn't one of these signs. It does not
> function to stabilize the critter for knuckle walking *unless* it is
> supporting its weight on the forelimbs. Yet there's no signs the arms
> were designed for this, not in the water, not on land, not anywhere.
Ok. I admit that interpreting the notches as evidence for some kind of
early knuckle-walking is rather speculative. But I think they are far
more likely to be have used for somthing than the rather fanciful
notion that they were merely vestigial of some ancestral
knuckle-walking ancestor - of which no evidence has ever been found.
Perhaps there is another explanation for these traits which does not
require any link with knuckle-walking. I'd be happy with that. An
early adopter of some kind of move towards k-w-ing seems the best
guess for me.
> >> The trait is a minor component of knuckle walking which, on it's own,
> >> doesn't have a functionality. It's part of a complex of traits that on its
> >> own is rather worthless.
> >
> >If most of the body weight was not bearing down on the forarms I can't
> >see why it'd be worthless to stabilise the wrists for support.
>
> How again are you proposing this? I'm honestly perplexed. You're having
> them just sort of lightly drag their arms just for a few seconds or
> something and this is enough to get a notch but no other signs that they
> used their arms for any support at all? And this makes more
> sense because they were already bipedal in the water? ROTHLMMFAO!
No, I suppose I'm arguing that they'd be weight bearing but only for a
very small fraction of the time - perhaps as they hauled themselves up
out of the water. You would concede, wouldn't you?, that a
fully-kuckle-walking quadruped like a chimp would put far greater
stresses on his forearms than a putative wading ancestor which did so
merely to get out of the water and perhaps for a few ground steps
before climbing a tree?
> >Well how do you think knuckle-walking began? I think it makes most
> >sense in a move from upright posture (perhaps brachiating, perhaps
> >wading) to quadrupedal. Knuckle-walking must have evolved somehow.
> >With these traits coming in somehow, perhaps some before others. How
> >do you see that scenario panning out, and why, specifically, do you
> >discount wading as a possible precursor?
>
> All solid indications are that we and the knucklewalkers share an arboreal
> brachiating past. We've got all sorts of vestigial holdovers from this,
> though it happened many millions of years ago. We've got wide torsos,
> elongated clavicals, dorsally placed scapulae, a wide range of movement in
> the shoulder and elbow and wrist, all of which we share with extant apes.
> These are all notable signs of a brachiator. Brachiators have a rather
> upright posture. IF one becomes large and starts using its forelimbs for
> support, knucklewalking is a means of compromise since a baboon like
> quadrupedalism has been more or less ruled out by the preadaptations from
> brachiation.
>
> I don't know how knucklewalking began, but I'm pretty damn sure that your
> scenario doesn't flow. You're so hell-bent on making the environmental
> stressors easy that you all but take them away.
Now come on. That's not fair. I asked you how you thought k-w-ing
began. What i meant to do was to highlight that the full-set of k-w
traits must have evolved in a gradual way - perhaps some traits coming
in before others. You've simply avoided that issue here.
> We do know that *ever* animal that regularly supports itself shows
> particular signs. We do know that A.afarensis and A.anamensis do not show
> these signs.
Except they have notches on their distal radii.
> Yet you ingore all this, favoring a mode of movement totally unknown, with
> just a little bit of weight bearing (speculation- you have no evidence of
> this) for only a little bit of time, and from this you speculate
> (entirely-again you have no evidence) that this would result in the
> notched distal radii but not any of the features found in anything that
> uses its forlimbs for weight bearing activity.
Movement totally unknown? Come off it. Apes wade bipedally, Jason. And
guess how they get out of the water? That's right, their first step
out is to knuckle-walk.
I have no evidence that the earliest a'piths actually knuckle-walked
in this way, no. But then lack of evidence of an earlier
knuckle-walker than Lucy hasn't stopped you adopting the idea that it
was vestigial, has it?
Notches on the distal radii need an explanation. "They're a vestigial
hangover from an imaginary ancestral knuckle-walker" is no explanation
- it's a wild guess. At least I have an explanation.
> Do you really not understand why this all sounds so absurd? Why several
> speculative unknowns (probably unknowable) that may or may not even if
> true result in the pattern you detail, seem significantly less probably
> than the notches being vestigial.
What sounds absurd to me is that you seem so sure that the k-w traits
are vestigial even when the notches in the distal radii are the
earliest evidence for it in the fossil record.
> Vestigial traits exist, your incredulity that these could be vestigial
> notwithstanding. Your incredulity is that this piece of the body is so
> "exposed" that it couldn't have lasted for a million plus years. That's
> not science. That's merely your opinion, based on nothing more than your
> opinion, and running counter to the evidence that many so significantly
> "exposed" traits (like the form of our shoulder--a vestigial holdover from
> a brachiator), like a clavical, no longer necessarily so long in humans
> that, as a function of being so long, becomes the most oft broken bone in
> the body.)
But your shoulder explanation is just opinion too. How do you know it
wasn't selected for to help swimming?
> >Wading has lots of support. Extant apes are pretty much 100% bipedal
> >in water and so it is likely that a'piths would be too - and their
> >paleohabitats seem to have been predominantly gallery
> >forest/riverside/lakeside niches - which is also supportive of the
> >model.
>
> Now waitaminute! You're saing these creatures are 100% bipedal when
> wading. Ergo, no reason for support from the wrist. It must be then that
> they don't need the support from the wrist. It must then be whilst they
> are getting out of the water or have reached land that (and I apoligize
> for yelling, but you really don't seem to pick up on this poing) BY YOUR
> OWN SCENARIO THEY WOULD USE THEIR WRISTS. At this point, the support of
> the water is gone.
Huh? Apes wade bipedally Jason. When they get out of the water they
knuckle-walk. Where's your problem? I propose that a'pith did so too
but rather than get around on the ground as much as chimps they spent
more of that time in trees and more time wading.
> Or are you having them begin to knuckle walk in water deep enough to get
> some support (e.g. water up to their torso--less deep and they don't get
> the support) in contradiction to your "apes wade, even in water that's not
> so deep as to require it" pronouncement? If you're not here contradicting
> yourself, you've got to explain how using the arm for support isn't
> similarly using it to bear weight.
Knuckle-walking as they get OUT of the water, Jason. I've always
argued for that, what's your problem?
> >The only 'context' you refer to is your terrestrial bipedal assumption
> >which might just be wrong. The lack of features for weight bearing on
> >the upper arm are easily explained as evidence of an early
> >evolutionary form of knuckle-walking from a wading/brachiating
> >precursor.
>
> No, Algis. The context is weight bearing. That's a context that's
> totally independent of how much water these guys were in. If they need to
> stabilize their bodies with their forelimbs, they're loading the
> forelimbs. Animals that do this show signs of it. A.anamensis and
> A.afarensis do not show these signs. It's an unfortunate fact for your
> scenario. You want to be objective? Please admit this and stop parading
> around a fantasy.
But how much weight bearing? If a chimp is terrestrial say 50% of it's
waking day (bipedal terrestrially 3% and arboreal 47%) then it's
forearms are going to be bearing much of it's weight for that amount
of time. A putative aquarboreal ape would not be knuckle-walking for
50% of the time. I'd guess it would be arboreal 60%, bipedal wading
30% perhaps bepedal terrestrially 10% and knuckle-walking 10% - or
some formula of figures to that effect.
> >> It may not be dishonest, but it's not science either. To make the case
> >> you do, you've got to explain why their explanation (a vestigial holdover)
> >> is less likely than another explanation (and your own incredulity isn't
> >> sufficient--I'm aware that you have a hard time believing it) and why you
> >> can ignore the context of their pronouncement.
>
> >I tried. Plasticity in bone is such that even in one lifetime bone
> >grows to fit the stresses and strains being placed upon it during the
> >animal's development. The idea that a bony notch on such a vitally
> >important part of the body as the wrist would merely have remained
> >there as a ghost from a knuckle-walking past for one million years is
> >inconsistent with that fact.
>
> Your last statement is not at all substantiated. Please do take note of
> that. That the notch is inconsistent with being vestigial is *ENTIRELY*
> your assertion and nothing more. What again, save incredulity, is your
> argument that the trait cannot be vestigial? Why again, other than your
> pronouncement as such, is this region of the wrist so vital? What exactly
> does the notch prevent that would suggest that it would disappear so
> quickly if not under selection?
It is a bony growth which, according to you, had no function. It's not
so much that it would prevent it doing something - although it might
perhaps reduce the flexibility of movement in trees. It's that it is
using energy for no purpose. Not only in the development of that notch
but in the maintenance of it throughout it's entire lifetime. Other
than your shoulder fantasy (a vestigial trait - from 20mya - of a
brachiating ancestor) can you name one bit of bone that has no
function at all in a human?
> >> In the context of what makes a knucklewalker a knucklewalker, it being a
> >> vestigial holdover makes more sense.
> >
> >In the context that the alternative explanation was an early
> >knuckle-walker I think the chance of it being a vestigial holdover is
> >farcically unlikely.
>
> And again, this is substantiated only by what you think and not any actual
> data, comparative, experimental, similative, or otherwise. It's a product
> again only of your incredulity which runs counter to other examples of
> vestigial holdovers which persist for much longer. Additionally, you
> *aren't* really proposing an alternative. You're providing a story, ripe
> with internal inconsistencies, whereby wading magically produces a
> situation that produces the notch, preadapting for knucklewalking, but
> produces no other features.
>
> To further complicate your scenario, you are either putting
> A.afarensis in a clade ancestral to the extant knucklewalkers,
> or instituting an additional instance of the evolution of knucklewalking
> independent of that seen in the extant apes. Both scenarios are
> exceptionally abusive to parsimony. If the former is the case, you've got
> ridiculous levels of homoplasy in dental characteristics coupled with
> radical (and seemingly untraceable) reversals in pelvis and hindlimb
> morphology in Gorilla and Pan.
>
> Do you really not see the problems?
Not necessarily ancestral. Perhaps it was just an early 'experiment'
with kn-ing - one that failed.
> >What evidence is there, in any case, that any hominoid knuckle-walked
> >before Lucy did? If you can show me some fossil evidence for an early
> >knuckle-walker I'd be more convinced but I don't think there is any.
> >Put in that context, your assumption that it was vestigial is contrary
> >to any fossil evidence and just a convenience to fit your model.
>
> There's no direct evidence that anything knucklewalked prior to the extant
> apes, but there's some evidence that we fall out in morphological analysis
> in a clade with the extant knucklewalkers. The true independence of
> character inheritance is difficult to untangle so this might be a product
> of measuring features which are not independent and not entirely tied to
> knucklewalking, but it's suggestive that we had a knucklewalking ancestor.
>
> Please again note: you use the line "[w]hat evidence is there, in any
> case, that any hominoid knuckle-walked before Lucy did?" This could
> easily be construed as suggesting that Lucy knuckle-walked. Again, just
> in case this is what you're suggesting, that's HIGHLY unlikely as there's
> considerable evidence that A.afarensis did not have forelimbs in any way
> consistent with knucklewalking.
I was not trying to slip that in actually.
I meant simply that as there is no evidence whatsoever that any
hominoid ever knuckle-walked before *the time* of Lucy then the
assumption that those traits she had which are analogoues to extant
knuckle-walkers were vestigial simply seems very far-fetched and, if I
dare say so, far more based on wishing to meet a nice agreed
story-line than my own explanation does.
> You further seem to be abusing the word "contrary" as in "[p]ut in that
> context, your assumption that it was vestigial is contrary to any fossil
> evidence and just a convenience to fit your model." That, Algis, is
> simply false. There's nothing contrary to the fossil evidence that says
> Lucy had an knucklewalking ancestor. The absense of evidence is not
> contrary. Again, I'm not saying this out of "convenience" to
> "my" model.
Ok, not 'contrary.' But I shall remember this next time you claim that
there is no fossil evidence to support the hypothesis that humans were
more aquatic in the past. Lack of such evidence clearly does not
inhibit you in comming to your own conclusions about the evolution of
knuckle-walking.
> >> I think you don't know much about functional anatomy, have zero idea how
> >> the trait functions, zero idea how it forms (if it is plastic, if it is
> >> under tighter genetic control) and are making things up to suit your
> >> purpose, all the while ignoring what is known about knucklewalkers.
> >
> >Oh wonderful. The ex cathedra (I know best) argument.
>
> I'd stop using it if you'd stop showing me that you know less. But
> actually, the argument wasn't that I know best, it's that you've
> demonstrated that you know so little (yet seem prepared to make claims
> based on what little you know and what you speculate beyond what you know,
> even when the speculation so often runs contrary to observations).
I'm learning. At least I think I am.
> >I read the Richmond and Strait article which made the function of the
> >notches in Pan/Gorilla fairly clear. I've been reading up about bone
> >plasticity and development and have been impressed with how plastic
> >they are. Charles Oxnard told me that in an experiment with rats, bone
> >morphology was drastically changed simply by the denervation of
> >muscle, even quite late in life.
> >
> >Considering that there's no fossil evidence for a knuckle-walking
> >ancestor of Lucy I think it is you who is making things up to suit
> >your story line.
>
> Think what you want. You're still wrong.
So sure, aren't you?
> >> >Why don't you focus on the issues and data instead of pouring slur on
> >> >those who happen to hold a different view to yourself?
> >>
> >> Why don't you make a better argument rather than raising personal
> >> incredulity as your foremost line of defense against evidence otherwise?
> >
> >I agree that personal incredulity is no good. The evidence for bone
> >plasticity and lack of a putative knuckle-walking ancestor of
> >australopithecus, however, is.
>
> Is what? Is evidence that we've got big breaks in the fossil record?
> What again are you saying about bone plasticity? You're tossing out these
> concepts, but you're not putting them together. In short, you're not
> making sense.
Is good.
The plasticity of bone, the way they develop, the way that bony tissue
is recycled and is under constant review by body stresses in a single
lifetime is inconsistent with the view that a notch on a bone would
remain unchanged, without any function, for one million years.
The fact that there is no evidence that any ape ever knuckle-walked
before Lucy lived stretches the credultiy that these traits were
vestigial even more.
How come you are so sceptical about evidence that favours the view
that Homo was more aquatic in the past but, apparently, have no need
for it at all when it comes to supporting the view that A'piths were
knuckle-walkers in their past?
Algis Kuliukas
Jason Eshleman
Algis Kuliukas <al...@RiverApes.com> wrote:
>j...@vidi.ucdavis.edu (Jason Eshleman) wrote in message news:<b9rae3$ml$1...@woodrow.ucdavis.edu>...
[gratuitous snipping--tired terrritory that seems to boil down to Algis's
own incredulity that a trait can be vestigial]
>Now come on. That's not fair. I asked you how you thought k-w-ing
>began. What i meant to do was to highlight that the full-set of k-w
>traits must have evolved in a gradual way - perhaps some traits coming
>in before others. You've simply avoided that issue here.
Creatures that use their forelimbs for support show clear signs of it.
That this happens in so many different lineages indicates to me that it's
not something that has to happen gradually. As you've mentioned, there's
some considerable plasticity in bone development. Why a creature that put
weight on the forelimbs didn't show any of the obvious signs of bearing
weight it still beyond me.
>
>> We do know that *ever* animal that regularly supports itself shows
>> particular signs. We do know that A.afarensis and A.anamensis do not show
>> these signs.
>
>Except they have notches on their distal radii.
That isn't a clear indicator of bearing weight. That's not one of those
keys that you see in a creature who uses its forelimbs to support itself.
>> Yet you ingore all this, favoring a mode of movement totally unknown, with
>> just a little bit of weight bearing (speculation- you have no evidence of
>> this) for only a little bit of time, and from this you speculate
>> (entirely-again you have no evidence) that this would result in the
>> notched distal radii but not any of the features found in anything that
>> uses its forlimbs for weight bearing activity.
>Movement totally unknown? Come off it. Apes wade bipedally, Jason. And
>guess how they get out of the water? That's right, their first step
>out is to knuckle-walk.
I was refering to your sideways waddle, unknown outside of crustaceans.
>I have no evidence that the earliest a'piths actually knuckle-walked
>in this way, no. But then lack of evidence of an earlier
>knuckle-walker than Lucy hasn't stopped you adopting the idea that it
>was vestigial, has it?
No, it hasn't. Not finding an earlier knucklewalker means we haven't
found an earlier knucklewalker. We've got big gaps in the fossil record.
You are aware of this, no? The conclusion that it's vestigial comes from
the fact that it makes phylogenetic sense in this context, it's a
parsimonious explanation of character evolution, and it doesn't contradict
the rest of the forelimb. An earlier critter, seemingly phylogenetically
ancestral to Lucy, with a less pronounced distal notch would be a problem
for this view. The lack of an early knucklewalker simply underlies the
problems with the fossil record.
>Notches on the distal radii need an explanation. "They're a vestigial
>hangover from an imaginary ancestral knuckle-walker" is no explanation
>- it's a wild guess. At least I have an explanation.
They're vestigial *is* an explanation. It's one you don't like, clearly,
but it's an explanation and one that actually fits with the data we have.
It's one that makes phylogenetic sense. You may have an explanation, but
not one that makes phylogenetic sense, not one that fits with the rest of
the evidence, and not one that even necessarily explains the trait.
>> Do you really not understand why this all sounds so absurd? Why several
>> speculative unknowns (probably unknowable) that may or may not even if
>> true result in the pattern you detail, seem significantly less probably
>> than the notches being vestigial.
>
>What sounds absurd to me is that you seem so sure that the k-w traits
>are vestigial even when the notches in the distal radii are the
>earliest evidence for it in the fossil record.
I'm sure based on the evidence we have. See above.
I'm sure that there are many creatures and many traits that have
precursors that we haven't found yet. This doesn't mean that the earliest
form we see of each is the earliest form out there.
Are you at all bothered by the fact that we don't have any signs of
*later* knucklewalkers who are more adapted to knucklewalking than simply
having the notched distal radii? Nothing from 3 million years until
extant apes. I'm curious why it seems you're bothered by the lack of
really old stuff but seemingly less bothered by the lack of stuff between
3 million years and now.
>> Vestigial traits exist, your incredulity that these could be vestigial
>> notwithstanding. Your incredulity is that this piece of the body is so
>> "exposed" that it couldn't have lasted for a million plus years. That's
>> not science. That's merely your opinion, based on nothing more than your
>> opinion, and running counter to the evidence that many so significantly
>> "exposed" traits (like the form of our shoulder--a vestigial holdover from
>> a brachiator), like a clavical, no longer necessarily so long in humans
>> that, as a function of being so long, becomes the most oft broken bone in
>> the body.)
>
>But your shoulder explanation is just opinion too. How do you know it
>wasn't selected for to help swimming?
A strange adaptation then, as shoulders create huge amounts of drag and is
totally like the shoulder of any other swimming animal. That's not
opinion. I don't know that it wasn't selected for in swimming, but I do
know that the the human shoulder (actually an ape brachiating shoulder)
doesn't seem at all associated with swimming. That's not opinion either.
>> >Wading has lots of support. Extant apes are pretty much 100% bipedal
>> >in water and so it is likely that a'piths would be too - and their
>> >paleohabitats seem to have been predominantly gallery
>> >forest/riverside/lakeside niches - which is also supportive of the
>> >model.
>>
>> Now waitaminute! You're saing these creatures are 100% bipedal when
>> wading. Ergo, no reason for support from the wrist. It must be then that
>> they don't need the support from the wrist. It must then be whilst they
>> are getting out of the water or have reached land that (and I apoligize
>> for yelling, but you really don't seem to pick up on this poing) BY YOUR
>> OWN SCENARIO THEY WOULD USE THEIR WRISTS. At this point, the support of
>> the water is gone.
>Huh? Apes wade bipedally Jason. When they get out of the water they
>knuckle-walk. Where's your problem? I propose that a'pith did so too
>but rather than get around on the ground as much as chimps they spent
>more of that time in trees and more time wading.
The heart of your scenario is that they knucklewalked in a magic ratio
that produced only one trait (the notched distal radii--which isn't
universal in animals who use their forelimbs for support) but no others.
It's the lack of other signs that they used their forelimbs for locomotion
at all that I have problems with.
>> Or are you having them begin to knuckle walk in water deep enough to get
>> some support (e.g. water up to their torso--less deep and they don't get
>> the support) in contradiction to your "apes wade, even in water that's not
>> so deep as to require it" pronouncement? If you're not here contradicting
>> yourself, you've got to explain how using the arm for support isn't
>> similarly using it to bear weight.
>
>Knuckle-walking as they get OUT of the water, Jason. I've always
>argued for that, what's your problem?
No evidence for it and evidence against it as their limbs weren't adapted
for knucklewalking (certainly not their knuckles or elbows). That's the
problem.
>> >The only 'context' you refer to is your terrestrial bipedal assumption
>> >which might just be wrong. The lack of features for weight bearing on
>> >the upper arm are easily explained as evidence of an early
>> >evolutionary form of knuckle-walking from a wading/brachiating
>> >precursor.
>>
>> No, Algis. The context is weight bearing. That's a context that's
>> totally independent of how much water these guys were in. If they need to
>> stabilize their bodies with their forelimbs, they're loading the
>> forelimbs. Animals that do this show signs of it. A.anamensis and
>> A.afarensis do not show these signs. It's an unfortunate fact for your
>> scenario. You want to be objective? Please admit this and stop parading
>> around a fantasy.
>But how much weight bearing? If a chimp is terrestrial say 50% of it's
>waking day (bipedal terrestrially 3% and arboreal 47%) then it's
>forearms are going to be bearing much of it's weight for that amount
>of time. A putative aquarboreal ape would not be knuckle-walking for
>50% of the time. I'd guess it would be arboreal 60%, bipedal wading
>30% perhaps bepedal terrestrially 10% and knuckle-walking 10% - or
>some formula of figures to that effect.
So your totally depending on a rare trait (the notch) being something
necessary for tiny amounts of time, selected for quickly, but the more
universal traits seen in quadrupeds don't develop so quickly such that
limited time quadrupedally results in nothing? Do you not see the problem
with this?
It's a bony growth which (to the best of our knowledge) didn't do anything
in A.afarensis or A.anamensis but does serve as a PART of a complete
knucklewalking complex.
It might reduce flexibility of the wrist in the trees, but please admit
you have no data to confirm this.
I'm curious why you say it was using energy. It's more difficult for the
bone to develop the notch than not to? So much energy as to be
selectively disadvantageous? Please admit that here too you have no data
to support this proposition.
>> >> In the context of what makes a knucklewalker a knucklewalker, it being a
>> >> vestigial holdover makes more sense.
>> >
>> >In the context that the alternative explanation was an early
>> >knuckle-walker I think the chance of it being a vestigial holdover is
>> >farcically unlikely.
>>
>> And again, this is substantiated only by what you think and not any actual
>> data, comparative, experimental, similative, or otherwise. It's a product
>> again only of your incredulity which runs counter to other examples of
>> vestigial holdovers which persist for much longer. Additionally, you
>> *aren't* really proposing an alternative. You're providing a story, ripe
>> with internal inconsistencies, whereby wading magically produces a
>> situation that produces the notch, preadapting for knucklewalking, but
>> produces no other features.
>>
>> To further complicate your scenario, you are either putting
>> A.afarensis in a clade ancestral to the extant knucklewalkers,
>> or instituting an additional instance of the evolution of knucklewalking
>> independent of that seen in the extant apes. Both scenarios are
>> exceptionally abusive to parsimony. If the former is the case, you've got
>> ridiculous levels of homoplasy in dental characteristics coupled with
>> radical (and seemingly untraceable) reversals in pelvis and hindlimb
>> morphology in Gorilla and Pan.
>>
>> Do you really not see the problems?
>
>Not necessarily ancestral. Perhaps it was just an early 'experiment'
>with kn-ing - one that failed.
I can see why it failed since the creatures had no signs of being able to
knucklewalk.
>> >What evidence is there, in any case, that any hominoid knuckle-walked
>> >before Lucy did? If you can show me some fossil evidence for an early
>> >knuckle-walker I'd be more convinced but I don't think there is any.
>> >Put in that context, your assumption that it was vestigial is contrary
>> >to any fossil evidence and just a convenience to fit your model.
>>
>> There's no direct evidence that anything knucklewalked prior to the extant
>> apes, but there's some evidence that we fall out in morphological analysis
>> in a clade with the extant knucklewalkers. The true independence of
>> character inheritance is difficult to untangle so this might be a product
>> of measuring features which are not independent and not entirely tied to
>> knucklewalking, but it's suggestive that we had a knucklewalking ancestor.
>>
>> Please again note: you use the line "[w]hat evidence is there, in any
>> case, that any hominoid knuckle-walked before Lucy did?" This could
>> easily be construed as suggesting that Lucy knuckle-walked. Again, just
>> in case this is what you're suggesting, that's HIGHLY unlikely as there's
>> considerable evidence that A.afarensis did not have forelimbs in any way
>> consistent with knucklewalking.
>
>I was not trying to slip that in actually.
>
>I meant simply that as there is no evidence whatsoever that any
>hominoid ever knuckle-walked before *the time* of Lucy then the
>assumption that those traits she had which are analogoues to extant
>knuckle-walkers were vestigial simply seems very far-fetched and, if I
>dare say so, far more based on wishing to meet a nice agreed
>story-line than my own explanation does.
There's no evidence that anything other than the extant apes
knucklewalked. Not before Lucy or AFTER Lucy. But unless you're trying
to say that it evolved independently in gorillas and chimps in the last
few hundred years since the anatomy of Pan and Gorilla has been studied,
it had to originate some time and clearly the fossil record hasn't done
much to preserve this.
I'm sure that you're abusing the data, not putting forward a believable
scenario. I've reviewed papers and if I got a paper why hypotheses as
convoluted as I'm seeing here, I'd reject them out of hand because they
don't make sense and yes, I'm sure what you've presented doesn't make
sense.
I'm sure that I'm not making things up to suit my story line because I'm
not making up a story line. You are wrong about that and yes, I'm sure of
it.
>> >> >Why don't you focus on the issues and data instead of pouring slur on
>> >> >those who happen to hold a different view to yourself?
>> >>
>> >> Why don't you make a better argument rather than raising personal
>> >> incredulity as your foremost line of defense against evidence otherwise?
>> >
>> >I agree that personal incredulity is no good. The evidence for bone
>> >plasticity and lack of a putative knuckle-walking ancestor of
>> >australopithecus, however, is.
>>
>> Is what? Is evidence that we've got big breaks in the fossil record?
>> What again are you saying about bone plasticity? You're tossing out these
>> concepts, but you're not putting them together. In short, you're not
>> making sense.
>
>Is good.
>
>The plasticity of bone, the way they develop, the way that bony tissue
>is recycled and is under constant review by body stresses in a single
>lifetime is inconsistent with the view that a notch on a bone would
>remain unchanged, without any function, for one million years.
Again, your pronouncement. I have my doubts that you know enough about
the subject to say this with any certainty.
>The fact that there is no evidence that any ape ever knuckle-walked
>before Lucy lived stretches the credultiy that these traits were
>vestigial even more.
Why? Because we have an incomplete fossil record? Remember that prior to
the mid 1990s we didn't have much evidence that there was any hominid
older than A.afarensis. Yet one must have existed. Would you be
similarly incredulous that Lucy had parents because we didn't find them in
the fossil record?
>How come you are so sceptical about evidence that favours the view
>that Homo was more aquatic in the past but, apparently, have no need
>for it at all when it comes to supporting the view that A'piths were
>knuckle-walkers in their past?
Because we have clear evidence that knucklewalkers are adapted for
knucklewalking, a form of quadrupedal locomotion. We do not similarly
seem signs of quadrupedal locomotion in Lucy.
We have no clear evidence that humans are adapted (this word have a real
meaning) for being aquatic. We have a hodgepodge with internal
inconsistencies.
Algis Kuliukas
> In article <77a70442.03051...@posting.google.com>,
> Algis Kuliukas <al...@RiverApes.com> wrote:
> >j...@vidi.ucdavis.edu (Jason Eshleman) wrote in message news:<b9rae3$ml$1...@woodrow.ucdavis.edu>...
>
> [gratuitous snipping--tired terrritory that seems to boil down to Algis's
> own incredulity that a trait can be vestigial]
I agree this discussion doesn't seem to be going anywhere. So I'm
snipping everything but your specific questions or challenges.
> >Now come on. That's not fair. I asked you how you thought k-w-ing
> >began. What i meant to do was to highlight that the full-set of k-w
> >traits must have evolved in a gradual way - perhaps some traits coming
> >in before others. You've simply avoided that issue here.
>
> Creatures that use their forelimbs for support show clear signs of it.
> That this happens in so many different lineages indicates to me that it's
> not something that has to happen gradually. As you've mentioned, there's
> some considerable plasticity in bone development. Why a creature that put
> weight on the forelimbs didn't show any of the obvious signs of bearing
> weight it still beyond me.
Features evolve slowly. There must have been a transitional stage when
a brachiating (or wading) ape first started getting down on all fours.
It is logical that during that transitional stage some knuckle-walking
traits would have been present whilst others were absent and/or some
traits would have indicated some intermediate function. That's why I
asked the question, but you don't seem to be able to accept that such
traits could have evolved gradually at all. It's all or nothing with
you: Fully weight bearing or not weight bearing at all. Is that how
you imagine bipedalism evolved too? One day we were knuckle-walkers
and then suddenly in a magical saltatory leap we became bipedal
because it was ... well so much more efficient? You know - I think
that is exactly how you see it happenning. There's never any room for
comprimise or intermediates in your models.
> No, it hasn't. Not finding an earlier knucklewalker means we haven't
> found an earlier knucklewalker. We've got big gaps in the fossil record.
> You are aware of this, no? The conclusion that it's vestigial comes from
> the fact that it makes phylogenetic sense in this context, it's a
> parsimonious explanation of character evolution, and it doesn't contradict
> the rest of the forelimb. An earlier critter, seemingly phylogenetically
> ancestral to Lucy, with a less pronounced distal notch would be a problem
> for this view. The lack of an early knucklewalker simply underlies the
> problems with the fossil record.
Of course I'm aware of the gaps. But I dispute the 'sense' you seem to
think it makes.
It seems to me we have the following evidence for knuckle-walking
3.5my A. afarensis (mild)
Extant Pan/Gorilla (strong)
Extant Homo (no k-w)
and that's it. Not much, I know.
From that you infer...
Prev (brach.) -----LCA (k-w) ----- Pan/Gorilla (k-w)
\
\
A.pith (vestigial k-w)
\
--------Homo (gone)
It seems to me to be more parsimoniuos to assume this...
--------------------------- Pan/Gorilla (k-w)
/
/
LCA -------A.pith (mild k-w)------ + (extinct)
\
\
--------------------------- Homo (no k-w)
> Are you at all bothered by the fact that we don't have any signs of
> *later* knucklewalkers who are more adapted to knucklewalking than simply
> having the notched distal radii? Nothing from 3 million years until
> extant apes. I'm curious why it seems you're bothered by the lack of
> really old stuff but seemingly less bothered by the lack of stuff between
> 3 million years and now.
We only have three bits of evidence: Extant k-w-ers, Extant
non-k-w-ers and 3.5my with some k-w traits. It seems to me to be less
parsimonious to assume that the k-w-ing was going on before (7-8mya?),
have no evidence for that, or earlier evolution of it and then to
assume that some kept it and some lost it rather than to assume that
only the extant apes ever really had (have) it and the 3.5mya evidence
indicates it evolving.
> >But your shoulder explanation is just opinion too. How do you know it
> >wasn't selected for to help swimming?
>
> A strange adaptation then, as shoulders create huge amounts of drag and is
> totally like the shoulder of any other swimming animal. That's not
> opinion. I don't know that it wasn't selected for in swimming, but I do
> know that the the human shoulder (actually an ape brachiating shoulder)
> doesn't seem at all associated with swimming. That's not opinion either.
Humans, you may have noticed, use their shoulders to swim. We are
better swimmers than other primates (esp. chimps) so the point you
make here is just wishful thinking. The idea that the morphology of a
human shoulder is a vestigial remnant of some brachiating past what
some 15mya is just crazy. Yes, I know. Personal incredulity squared.
> The heart of your scenario is that they knucklewalked in a magic ratio
> that produced only one trait (the notched distal radii--which isn't
> universal in animals who use their forelimbs for support) but no others.
> It's the lack of other signs that they used their forelimbs for locomotion
> at all that I have problems with.
k-w traits must have evolved somehow - whether or not wading was
involved. How do you think it happenned? In one magical saltatory
leap? All the traits, all at once? "On the third day he said let there
be knuckle-walkers with notches in their distal radii and full
weight-bearing forelimbs... and he saw that it was good."
> So your totally depending on a rare trait (the notch) being something
> necessary for tiny amounts of time, selected for quickly, but the more
> universal traits seen in quadrupeds don't develop so quickly such that
> limited time quadrupedally results in nothing? Do you not see the problem
> with this?
Not really.
> It's a bony growth which (to the best of our knowledge) didn't do anything
> in A.afarensis or A.anamensis but does serve as a PART of a complete
> knucklewalking complex.
>
> It might reduce flexibility of the wrist in the trees, but please admit
> you have no data to confirm this.
I admit I have no data but it's still likely to be true. A bony notch
'designed' to restrict the movement of the wrist whilst k-w-ing is
likely to restrict the movement in trees too isn't it?
> I'm curious why you say it was using energy. It's more difficult for the
> bone to develop the notch than not to? So much energy as to be
> selectively disadvantageous? Please admit that here too you have no data
> to support this proposition.
I admit I have no data but it's still likely to be true. Just basic
skeletal biology really, Jason. Every notch that has function has to
be actively maintained. If it had no function it would have atrophied.
You do know about how bone gets recycled, don't you?
> >The plasticity of bone, the way they develop, the way that bony tissue
> >is recycled and is under constant review by body stresses in a single
> >lifetime is inconsistent with the view that a notch on a bone would
> >remain unchanged, without any function, for one million years.
>
> Again, your pronouncement. I have my doubts that you know enough about
> the subject to say this with any certainty.
And I'm beginning to have my doubts that you know as much about this
as you'd like me to believe.
> >The fact that there is no evidence that any ape ever knuckle-walked
> >before Lucy lived stretches the credultiy that these traits were
> >vestigial even more.
>
> Why? Because we have an incomplete fossil record? Remember that prior to
> the mid 1990s we didn't have much evidence that there was any hominid
> older than A.afarensis. Yet one must have existed. Would you be
> similarly incredulous that Lucy had parents because we didn't find them in
> the fossil record?
Of course not. Why does the lack of fossil evidence stretch the
credibility of the vestigial argument? Because you have no data
whatsoever on which to base the assumption that any such type of
locomotion happenend before.
It's odd - we have evidence that the LCA might have been bipedal
(Orrorin & Sahelanthropus both may have preceded the LCA according to
some interpretations of the molecular data) but we have no evidence at
all that the LCA was a knuckle-walker. And yet you *choose to believe*
the later even to the extent that you have to cast further serious
doubts on the very essence of the molecular data to accomodate that
view.
You keep playing that tape recording about how your model makes more
phylogenetic sense but the more I think about it the less
evidence-based it is. I think you are just trying to pull the wool
over my eyes and failing badly.
> >How come you are so sceptical about evidence that favours the view
> >that Homo was more aquatic in the past but, apparently, have no need
> >for it at all when it comes to supporting the view that A'piths were
> >knuckle-walkers in their past?
>
> Because we have clear evidence that knucklewalkers are adapted for
> knucklewalking, a form of quadrupedal locomotion. We do not similarly
> seem signs of quadrupedal locomotion in Lucy.
So - either it's a fully quadrupedal fully-weight-baring
knuckle-walker or it's not. Black or White. On or Off. How on earth do
you teach anything to do with evolution? Are you a creationist in
disguise?
> We have no clear evidence that humans are adapted (this word have a real
> meaning) for being aquatic. We have a hodgepodge with internal
> inconsistencies.
We swim better than chimps and we are clearly, blatently obviously
more adapted to moving through water than they are. What more evidence
do you need?
Algis Kuliukas
Jason Eshleman
>j...@vidi.ucdavis.edu (Jason Eshleman) wrote in message news:<b9u25r$jal$1...@woodrow.ucdavis.edu>...
>> In article <77a70442.03051...@posting.google.com>,
>> Algis Kuliukas <al...@RiverApes.com> wrote:
>> >j...@vidi.ucdavis.edu (Jason Eshleman) wrote in message news:<b9rae3$ml$1...@woodrow.ucdavis.edu>...
>>
>> [gratuitous snipping--tired terrritory that seems to boil down to Algis's
>> own incredulity that a trait can be vestigial]
>
>I agree this discussion doesn't seem to be going anywhere. So I'm
>snipping everything but your specific questions or challenges.
>
>> >Now come on. That's not fair. I asked you how you thought k-w-ing
>> >began. What i meant to do was to highlight that the full-set of k-w
>> >traits must have evolved in a gradual way - perhaps some traits coming
>> >in before others. You've simply avoided that issue here.
>>
>> Creatures that use their forelimbs for support show clear signs of it.
>> That this happens in so many different lineages indicates to me that it's
>> not something that has to happen gradually. As you've mentioned, there's
>> some considerable plasticity in bone development. Why a creature that put
>> weight on the forelimbs didn't show any of the obvious signs of bearing
>> weight it still beyond me.
>
>Features evolve slowly.
That is a major point of contention in evolutionary biology. Some
features appear not to evolve slowly but sprout up all at once. Whether or
not this is indicative of the way the traits evolve or simply a product of
the fossil record keeping is unclear, but it's not clear that a feature
must evolve slowly. Highly selectively advantageous traits do seem to
burst on the scene in short order.
>There must have been a transitional stage when
>a brachiating (or wading) ape first started getting down on all fours.
Yes, but for how long this transition would have persisted is unclear.
Currently, the notched radii shows up for a million years (in A.anamensis
through late A.afarensis) with no signs of morphological modification. It
does not look like a knucklewalking complex is developing over this
period.
>It is logical that during that transitional stage some knuckle-walking
>traits would have been present whilst others were absent and/or some
>traits would have indicated some intermediate function. That's why I
>asked the question, but you don't seem to be able to accept that such
>traits could have evolved gradually at all. It's all or nothing with
>you: Fully weight bearing or not weight bearing at all. Is that how
>you imagine bipedalism evolved too? One day we were knuckle-walkers
>and then suddenly in a magical saltatory leap we became bipedal
>because it was ... well so much more efficient? You know - I think
>that is exactly how you see it happenning. There's never any room for
>comprimise or intermediates in your models.
Their can be intermediates, but we don't see an intermediate. We see a
creature with *no* adaptation for weight bearing at 4 million years ago,
and a creature that similarly has no adaptations for weight bearing at 3
million years ago. These two creatures share derived characteristics
indicating that at the very least they're sister taxa if not actually
ancestor-descendant.
The notched distal radii are *not* a clear sign of bearing weight.
They're not universal to weight bearing. It's unclear how the trait
develops, but I'm exceptionally suspicious that you can have selection or
developmental limitations for *stability* without selection or
developmental limitations for bearing weight. If there's no load, there's
nothing to stabilize. These creatures, over a million years, show no
signs of needing to load the forelimbs.
>> No, it hasn't. Not finding an earlier knucklewalker means we haven't
>> found an earlier knucklewalker. We've got big gaps in the fossil record.
>> You are aware of this, no? The conclusion that it's vestigial comes from
>> the fact that it makes phylogenetic sense in this context, it's a
>> parsimonious explanation of character evolution, and it doesn't contradict
>> the rest of the forelimb. An earlier critter, seemingly phylogenetically
>> ancestral to Lucy, with a less pronounced distal notch would be a problem
>> for this view. The lack of an early knucklewalker simply underlies the
>> problems with the fossil record.
>
>Of course I'm aware of the gaps. But I dispute the 'sense' you seem to
>think it makes.
The sense is that A.afarensis has many derived traits shared with Homo
that are not shared with Pan or Gorilla, making it exceedingly unlikely
that it is ancestral to the latter pair.
>It seems to me we have the following evidence for knuckle-walking
>
>3.5my A. afarensis (mild)
Sorry, I've got to correct you. We've got A.anamesis (4.2) with the same
trait as A.afarensis. Further your characterization of the evidence for
knucklewalking isn't "mild." It's almost completely non-existant.
There's considerable evidence that they didn't use their forelimbs for
support, not at all.
>Extant Pan/Gorilla (strong)
>Extant Homo (no k-w)
>
>and that's it. Not much, I know.
>
>From that you infer...
>
>Prev (brach.) -----LCA (k-w) ----- Pan/Gorilla (k-w)
> \
> \
> A.pith (vestigial k-w)
> \
> --------Homo (gone)
>
>
>It seems to me to be more parsimoniuos to assume this...
>
> --------------------------- Pan/Gorilla (k-w)
> /
> /
>LCA -------A.pith (mild k-w)------ + (extinct)
> \
> \
> --------------------------- Homo (no k-w)
I'm not sure what you mean by parsimonious here. You're ignoring the
suite of derived traits that unite Homo and apiths. And again, you're
ignoring that there is substantial evidence that Apiths didn't
knucklewalk.
You'll have to explain again what you mean by parsimony. I don't think
you are using it in the same sense as an evolutionary biologist.
Most realistic is
/------------------------------------------extant African Apes
LCA(knucklewalker)
\___(vestig of KW)_________________________apiths
|
\_(lost vestig)_______________________Homo
With apiths as a sister taxa (if not actually ancestral) to Homo.
This explains the *derived* characteristics of apiths and Homo and
minimizes convergence and duplicate character evolution. Your scenario
doesn't account for anything other than knucklewalking.
>> Are you at all bothered by the fact that we don't have any signs of
>> *later* knucklewalkers who are more adapted to knucklewalking than simply
>> having the notched distal radii? Nothing from 3 million years until
>> extant apes. I'm curious why it seems you're bothered by the lack of
>> really old stuff but seemingly less bothered by the lack of stuff between
>> 3 million years and now.
>
>We only have three bits of evidence: Extant k-w-ers, Extant
>non-k-w-ers and 3.5my with some k-w traits. It seems to me to be less
>parsimonious to assume that the k-w-ing was going on before (7-8mya?),
>have no evidence for that, or earlier evolution of it and then to
>assume that some kept it and some lost it rather than to assume that
>only the extant apes ever really had (have) it and the 3.5mya evidence
>indicates it evolving.
You're taking absense of evidence to mean an evidence of absense.
That's sketchy, real sketchy. Futher, accepting your scenario means
accepting that something that doesn't show any real signs of
quadrupedalism was somehow a very limited quadruped for about a million
years. Your position is really rather untenable with the current data.
And of course why you need apiths to be part time quadrupeds from 4 to 3
million years is TOTALLY beyond me. They were very capable of terrestrial
bipedalism. This seems abundantly clear from both their morphology and
the fact that we have tracks made by a biped during this period.
And again, I take extreme issue with your use of the word "parsimony." You
are not using it in the sense that evolutionary biologists take it to
mean.
You seem to take issue with some lineages keeping a trait while other
branches lose it. Yet this is EXACTLY what happens in evolution. I'm
curious again why you have problems with it. You have some rather
pronounced bones to pick (pun intended) with some rather basic concepts in
evolutionary biology it would seem.
>> >But your shoulder explanation is just opinion too. How do you know it
>> >wasn't selected for to help swimming?
>>
>> A strange adaptation then, as shoulders create huge amounts of drag and is
>> totally like the shoulder of any other swimming animal. That's not
>> opinion. I don't know that it wasn't selected for in swimming, but I do
>> know that the the human shoulder (actually an ape brachiating shoulder)
>> doesn't seem at all associated with swimming. That's not opinion either.
>
>Humans, you may have noticed, use their shoulders to swim. We are
>better swimmers than other primates (esp. chimps) so the point you
>make here is just wishful thinking. The idea that the morphology of a
>human shoulder is a vestigial remnant of some brachiating past what
>some 15mya is just crazy. Yes, I know. Personal incredulity squared.
On the contrary Algis, you're simply wrong.
Our shoulder morphology is virtually identical to the morphology of a
gibbon, an chimp, a gorilla, an orang. The parsimonious explanation (and
I'm using this term in the sense of an evolutionary biologist), knowing
that all five genera are closely related, is that this virtually identical
morphology is inherited from a common ancestor. Whether or not it's still
of use in the various lineages is a different matter, but it's quite
clearly a brachiationist's shoulder. The convergence with Platyrrhini
brachiators indicates this further.
Could it be that some swimming stroke served to maintain selection on our
shoulder? Possibly, but why then do Gorillas (who are very largely
terrestrial) similarly maintain the shoulder? It's a handicap in
quadrupedal locomotion, necessitating an otherwise cumbersome form of
locomotion. Do they too maintain vestige because it's actually being used
for something? For what?
You're more than incredulous here, Algis. You're just making stuff up.
>> The heart of your scenario is that they knucklewalked in a magic ratio
>> that produced only one trait (the notched distal radii--which isn't
>> universal in animals who use their forelimbs for support) but no others.
>> It's the lack of other signs that they used their forelimbs for locomotion
>> at all that I have problems with.
>k-w traits must have evolved somehow - whether or not wading was
>involved. How do you think it happenned? In one magical saltatory
>leap? All the traits, all at once? "On the third day he said let there
>be knuckle-walkers with notches in their distal radii and full
>weight-bearing forelimbs... and he saw that it was good."
Spare me the creationist talk. It's not very cute, it's not very clever
and it's merely exposing yourself as incredulous. BFD.
My suspicion is that some of the apes got big and as a consequence, spent
more time on the ground out of necessity. I am not sure why, but getting
big seems to be one of those things that can happen in a lineage. It's
happened over and over in other lineages. Being on the ground, you'd
expect some need to get around on the ground. Having the handicap of a
brachiationist's shoulder, a more generalized quadrupedal gait wasn't
possible. Knucklewalking seems to be a compromise, an ability to use the
forelimbs for locomotion once the structure has been significantly altered
away from the structure common to many other primates. But there were
still many things in common with the forelimbs of the knucklewalkers
(specifically some robusticity in the elbows) and *all* other quadrupeds.
My suspicion is also that we are evolved from a knucklewalker and once
selection for these traits disappeared, the traits likewise disappeared,
the most conspicuous disappearing first.
What bothers me about your "gradual" scenario is two fold: a) we don't see
the gradual appearance of knucklewalking traits and we don't see any
signs of any quadrupedalism. We see a particular
trait that's there for a million years totally unpaired with any signs of
quadrupedalism. None. Zero. A notched distal radius is *not* a
conspicuous sign of using your forelimbs for locomotion at all. There are
other signs. Why, for a million years, are they totally absent?
We do, however, in these creatures, see clear signs of *bipedalism.*
>> So your totally depending on a rare trait (the notch) being something
>> necessary for tiny amounts of time, selected for quickly, but the more
>> universal traits seen in quadrupeds don't develop so quickly such that
>> limited time quadrupedally results in nothing? Do you not see the problem
>> with this?
>
>Not really.
Obviously you don't. I wish you luck trying to publish. The specialists
are going to eat you alive.
>> It's a bony growth which (to the best of our knowledge) didn't do anything
>> in A.afarensis or A.anamensis but does serve as a PART of a complete
>> knucklewalking complex.
>>
>> It might reduce flexibility of the wrist in the trees, but please admit
>> you have no data to confirm this.
>
>I admit I have no data but it's still likely to be true. A bony notch
>'designed' to restrict the movement of the wrist whilst k-w-ing is
>likely to restrict the movement in trees too isn't it?
I'm...sorry...difficult...to...type...over...laughter...
Must...not...stop...breathing!
I'm saving this one: "I admit I have no data but it's still more likely
to be true." -Algis
If that doesn't sum up your argument, I don't know what does. This is why
I accuse you of doing pseudoscience. You are not doing data analysis.
You don't even have any data. You're working on your hunch and concluding
it must be so.
>> I'm curious why you say it was using energy. It's more difficult for the
>> bone to develop the notch than not to? So much energy as to be
>> selectively disadvantageous? Please admit that here too you have no data
>> to support this proposition.
>
>I admit I have no data but it's still likely to be true. Just basic
>skeletal biology really, Jason. Every notch that has function has to
>be actively maintained. If it had no function it would have atrophied.
>You do know about how bone gets recycled, don't you?
See above:
"I admit I have no data but it's still more likely
to be true." -Algis
All notches have to have a function? Really? I'm curious where you get
this. My forensic osteo friends would take issue with this, as would my
functional anatomy friends. It's exactly those bizarre notches and
grooves that are their bread and butter.
>> >The plasticity of bone, the way they develop, the way that bony tissue
>> >is recycled and is under constant review by body stresses in a single
>> >lifetime is inconsistent with the view that a notch on a bone would
>> >remain unchanged, without any function, for one million years.
>>
>> Again, your pronouncement. I have my doubts that you know enough about
>> the subject to say this with any certainty.
>
>And I'm beginning to have my doubts that you know as much about this
>as you'd like me to believe.
Have your doubts. I don't care. I'm confident in what I know and what I
don't know.
"I admit I have no data but it's still more likely to be true." -Algis
>> >The fact that there is no evidence that any ape ever knuckle-walked
>> >before Lucy lived stretches the credultiy that these traits were
>> >vestigial even more.
>>
>> Why? Because we have an incomplete fossil record? Remember that prior to
>> the mid 1990s we didn't have much evidence that there was any hominid
>> older than A.afarensis. Yet one must have existed. Would you be
>> similarly incredulous that Lucy had parents because we didn't find them in
>> the fossil record?
>
>Of course not. Why does the lack of fossil evidence stretch the
>credibility of the vestigial argument? Because you have no data
>whatsoever on which to base the assumption that any such type of
>locomotion happenend before.
I have no *fossil* data. On the other hand, there's considerable
comparative data suggesting that the trait wasn't functional. There's
considerable phylogenetic data that suggests it wasn't developing. You
seem to want to ignore this.
>It's odd - we have evidence that the LCA might have been bipedal
>(Orrorin & Sahelanthropus both may have preceded the LCA according to
>some interpretations of the molecular data) but we have no evidence at
>all that the LCA was a knuckle-walker. And yet you *choose to believe*
>the later even to the extent that you have to cast further serious
>doubts on the very essence of the molecular data to accomodate that
>view.
Again, you're confusing no fossil data with no data. Seriously confusing
it. There's evidence that the LCA was a knucklewalker, evidence derived
from morphological studies of extant apes and humans and studies of the
fossil remains of extinct hominids. Please stop saying that there's no
data as if I was making this up.
>You keep playing that tape recording about how your model makes more
>phylogenetic sense but the more I think about it the less
>evidence-based it is. I think you are just trying to pull the wool
>over my eyes and failing badly.
Fine. Believe what you want.
But if you want anyone to accept your curious take on phylogeny, please do
be prepared to explain how you see convergence in the cranial morphology
within apiths and Homo to the exclusion of the extant apes and the
postcranial morphology of apiths and Homo to the exclusion of extant apes.
We see these things. Honest.
>> >How come you are so sceptical about evidence that favours the view
>> >that Homo was more aquatic in the past but, apparently, have no need
>> >for it at all when it comes to supporting the view that A'piths were
>> >knuckle-walkers in their past?
>>
>> Because we have clear evidence that knucklewalkers are adapted for
>> knucklewalking, a form of quadrupedal locomotion. We do not similarly
>> seem signs of quadrupedal locomotion in Lucy.
>
>So - either it's a fully quadrupedal fully-weight-baring
>knuckle-walker or it's not. Black or White. On or Off. How on earth do
>you teach anything to do with evolution? Are you a creationist in
>disguise?
Hey, Algis, the creationist slander will only make you look bad. If
you're just trying to be pissy, fuck off and die. Come back once you've
actually learned something. If you really think you're winning points,
I'm confident in my ability to teach evolutionary biology because I've got
a good track record doing it. You can say the same?
Again, for the umteenth time: there are ZERO characteristics of apiths
that are part of the common suite found in ALL quadrupeds related to
quadrupedalism. While it may be that there are shades between in an
idealized case, right here, with this real data there is not evidence that
we're not at a zero-level quadrupedalism.
>> We have no clear evidence that humans are adapted (this word have a real
>> meaning) for being aquatic. We have a hodgepodge with internal
>> inconsistencies.
>
>We swim better than chimps and we are clearly, blatently obviously
>more adapted to moving through water than they are. What more evidence
>do you need?
We're clearly better able to swim than chimps. You are inferring that the
difference is adaptive. Differences are not necessarily all adaptive.
Algis Kuliukas
> Algis Kuliukas <al...@RiverApes.com> wrote:
> >Features evolve slowly.
>
> That is a major point of contention in evolutionary biology. Some
> features appear not to evolve slowly but sprout up all at once. Whether or
> not this is indicative of the way the traits evolve or simply a product of
> the fossil record keeping is unclear, but it's not clear that a feature
> must evolve slowly. Highly selectively advantageous traits do seem to
> burst on the scene in short order.
>
> >There must have been a transitional stage when
> >a brachiating (or wading) ape first started getting down on all fours.
>
> Yes, but for how long this transition would have persisted is unclear.
> Currently, the notched radii shows up for a million years (in A.anamensis
> through late A.afarensis) with no signs of morphological modification. It
> does not look like a knucklewalking complex is developing over this
> period.
If you assume that they were terrestrial bipeds of course it could be
interpreted to look that way. If you assume that they were wading apes
then I think it's the best interpretation.
> >It is logical that during that transitional stage some knuckle-walking
> >traits would have been present whilst others were absent and/or some
> >traits would have indicated some intermediate function. That's why I
> >asked the question, but you don't seem to be able to accept that such
> >traits could have evolved gradually at all. It's all or nothing with
> >you: Fully weight bearing or not weight bearing at all. Is that how
> >you imagine bipedalism evolved too? One day we were knuckle-walkers
> >and then suddenly in a magical saltatory leap we became bipedal
> >because it was ... well so much more efficient? You know - I think
> >that is exactly how you see it happenning. There's never any room for
> >comprimise or intermediates in your models.
>
> Their can be intermediates, but we don't see an intermediate. We see a
> creature with *no* adaptation for weight bearing at 4 million years ago,
> and a creature that similarly has no adaptations for weight bearing at 3
> million years ago. These two creatures share derived characteristics
> indicating that at the very least they're sister taxa if not actually
> ancestor-descendant.
>
> The notched distal radii are *not* a clear sign of bearing weight.
> They're not universal to weight bearing. It's unclear how the trait
> develops, but I'm exceptionally suspicious that you can have selection or
> developmental limitations for *stability* without selection or
> developmental limitations for bearing weight. If there's no load, there's
> nothing to stabilize. These creatures, over a million years, show no
> signs of needing to load the forelimbs.
Ok but that's the point - you don't see intermediates. You seem to
have it fixed that there was a kind of switch from a brachiating
ancestor - no kw-ing traits - to a terrestrial quadrupedal one, the
LCA of Pan/Homo/A'pith - with full k-w-ing traits (without
intermediates) - and then another switch to full terrestrial
bipedalism (again with no intremediates) in A'piths.
I agree that often evolution *appears* to work rapidly. And yes this
could just be through gaps in the fossil record. But here we have
evidence that might be interpretted as showing a definite evolutionary
trend - with clear intermedites and no need for saltatory leaps.
Taking the same brachiating ancestral starting point we can have a
smooth transition from that to aquarboreality - a climbing/wading ape
which moves in an upright way. From there a slight move towards
terrestriality with some k-w-ing coming in (A'piths) and more coming
in with Pan/Gorilla.
> The sense is that A.afarensis has many derived traits shared with Homo
> that are not shared with Pan or Gorilla, making it exceedingly unlikely
> that it is ancestral to the latter pair.
>
> >It seems to me we have the following evidence for knuckle-walking
> >
> >3.5my A. afarensis (mild)
>
> Sorry, I've got to correct you. We've got A.anamesis (4.2) with the same
> trait as A.afarensis. Further your characterization of the evidence for
> knucklewalking isn't "mild." It's almost completely non-existant.
> There's considerable evidence that they didn't use their forelimbs for
> support, not at all.
Ok. thanks I forgot about the lake hominid. 'Mild' was shorthand for
'something that might, if you are completely crazy and don't just take
the opinions of others without questioning them as true, be a
reasonable alternative explanation.'
> >Extant Pan/Gorilla (strong)
> >Extant Homo (no k-w)
> >
> >and that's it. Not much, I know.
> >
> >From that you infer...
> >
> >Prev (brach.) -----LCA (k-w) ----- Pan/Gorilla (k-w)
> > \
> > \
> > A.pith (vestigial k-w)
> > \
> > --------Homo (gone)
> >
> >
> >It seems to me to be more parsimoniuos to assume this...
> >
> > --------------------------- Pan/Gorilla (k-w)
> > /
> > /
> >LCA -------A.pith (mild k-w)------ + (extinct)
> > \
> > \
> > --------------------------- Homo (no k-w)
>
> I'm not sure what you mean by parsimonious here. You're ignoring the
> suite of derived traits that unite Homo and apiths. And again, you're
> ignoring that there is substantial evidence that Apiths didn't
> knucklewalk.
> You'll have to explain again what you mean by parsimony. I don't think
> you are using it in the same sense as an evolutionary biologist.
I meant less changes necessary to make the model fit. I thought that
was what these phylogenetic studies of characters were all about.
My model... (looking only at k-w-ing traits)
> > -(1)------------------------- Pan/Gorilla (k-w)
> > /
> > /
> >LCA -----(1) A.pith (mild k-w)------ + (extinct)
> > \
> > \
> > --------------------------- Homo (no k-w)
- 2 changes...
>
> Most realistic is
>
> /------------------------------extant African Apes
> /
> (1) --LCA(knucklewalker)
> \_(1)__(vestig of KW)_________________________apiths
> (1)
> \_(lost vestig)_______________________Homo
3 changes
Perhaps I have completely misunderstood the concept but I think that
makes your model less parsimonious.
> With apiths as a sister taxa (if not actually ancestral) to Homo.
> This explains the *derived* characteristics of apiths and Homo and
> minimizes convergence and duplicate character evolution. Your scenario
> doesn't account for anything other than knucklewalking.
... but your model conveniently ignores the step for how k-w-ing came
in. You just assume that was the starting point. Assuming a somewhat
bipedal starting point (e.g. climber-wader) the whole model is more
parsimonios, as I understand it.
> >> Are you at all bothered by the fact that we don't have any signs of
> >> *later* knucklewalkers who are more adapted to knucklewalking than simply
> >> having the notched distal radii? Nothing from 3 million years until
> >> extant apes. I'm curious why it seems you're bothered by the lack of
> >> really old stuff but seemingly less bothered by the lack of stuff between
> >> 3 million years and now.
> >
> >We only have three bits of evidence: Extant k-w-ers, Extant
> >non-k-w-ers and 3.5my with some k-w traits. It seems to me to be less
> >parsimonious to assume that the k-w-ing was going on before (7-8mya?),
> >have no evidence for that, or earlier evolution of it and then to
> >assume that some kept it and some lost it rather than to assume that
> >only the extant apes ever really had (have) it and the 3.5mya evidence
> >indicates it evolving.
>
> You're taking absense of evidence to mean an evidence of absense.
> That's sketchy, real sketchy.
Well, it's an argument the aquasceptics use all the time against the
AAH.
On what basis do you assume the LCA was already a full knuckle-walker
if there is no fossil evidence whatsoever to back that view up? Other
than, of course, 'because I think it makes my model work better.'
> Futher, accepting your scenario means
> accepting that something that doesn't show any real signs of
> quadrupedalism was somehow a very limited quadruped for about a million
> years. Your position is really rather untenable with the current data.
If the earliest bipeds were waders and A'piths were too then it makes
perfect sense.
> And of course why you need apiths to be part time quadrupeds from 4 to 3
> million years is TOTALLY beyond me. They were very capable of terrestrial
> bipedalism. This seems abundantly clear from both their morphology and
> the fact that we have tracks made by a biped during this period.
Yes it looks like a contradiction. They have traits that appear to
make them bipeds, they have traits that appear to make them somewhat
arboreal and they have traits that appear (ok, to some) to make them
some kind of knuckle-walkers too. I can see why it's beyond you:
Because you *assume* they were terrestrial bipeds. I agree it doesn't
make sense that they'd be part-time quadrupeds if they were also
terrestrial bipeds. The contradictions are effortless removed, hoever,
if we just assume instead that the ir bipedalism was mainly for
wading. Three modes of locomotion for three different substrates.
> And again, I take extreme issue with your use of the word "parsimony." You
> are not using it in the sense that evolutionary biologists take it to
> mean.
I take it to mean - less evolutionary changes required to make the
model fit.
> You seem to take issue with some lineages keeping a trait while other
> branches lose it. Yet this is EXACTLY what happens in evolution. I'm
> curious again why you have problems with it. You have some rather
> pronounced bones to pick (pun intended) with some rather basic concepts in
> evolutionary biology it would seem.
No I don't. I have issues with you just assuming, as a convenient
starting point, that knuckle-walking traits had already, magically,
appeared so that your model works - even though there is no fossil
evidence for it.
> >> >But your shoulder explanation is just opinion too. How do you know it
> >> >wasn't selected for to help swimming?
> >>
> >> A strange adaptation then, as shoulders create huge amounts of drag and is
> >> totally like the shoulder of any other swimming animal. That's not
> >> opinion. I don't know that it wasn't selected for in swimming, but I do
> >> know that the the human shoulder (actually an ape brachiating shoulder)
> >> doesn't seem at all associated with swimming. That's not opinion either.
> >
> >Humans, you may have noticed, use their shoulders to swim. We are
> >better swimmers than other primates (esp. chimps) so the point you
> >make here is just wishful thinking. The idea that the morphology of a
> >human shoulder is a vestigial remnant of some brachiating past what
> >some 15mya is just crazy. Yes, I know. Personal incredulity squared.
>
> On the contrary Algis, you're simply wrong.
I might well be wrong. No, I probably am wrong. I've not studied the
shoulder much at all. I accept all I have is personal incredulity.
But..
So, no evolutionary pressure has come to bear on the morphology of not
only our shoulder but that of all the extant great apes too? They've
just remained vestigial from their brachiating ancestor? Come off it.
Any similarities in extant apes are clearly due to the pressence of
similar pressures - ie climbing.
> Our shoulder morphology is virtually identical to the morphology of a
> gibbon, an chimp, a gorilla, an orang. The parsimonious explanation (and
> I'm using this term in the sense of an evolutionary biologist), knowing
> that all five genera are closely related, is that this virtually identical
> morphology is inherited from a common ancestor. Whether or not it's still
> of use in the various lineages is a different matter, but it's quite
> clearly a brachiationist's shoulder. The convergence with Platyrrhini
> brachiators indicates this further.
... based on a brachiator's shoulder, granted. But - seeing we have
not been very arboreal for about 3mya - one that has been exposed to
and shaped by alternative forces since then. They're vestigial only in
the sense that if the body can make full use of an inherited feature
without modification it will.
> Could it be that some swimming stroke served to maintain selection on our
> shoulder? Possibly, but why then do Gorillas (who are very largely
> terrestrial) similarly maintain the shoulder? It's a handicap in
> quadrupedal locomotion, necessitating an otherwise cumbersome form of
> locomotion. Do they too maintain vestige because it's actually being used
> for something? For what?
>
> You're more than incredulous here, Algis. You're just making stuff up.
I wouldn't go that far!
> My suspicion is that some of the apes got big and as a consequence, spent
> more time on the ground out of necessity. I am not sure why, but getting
> big seems to be one of those things that can happen in a lineage. It's
> happened over and over in other lineages. Being on the ground, you'd
> expect some need to get around on the ground. Having the handicap of a
> brachiationist's shoulder, a more generalized quadrupedal gait wasn't
> possible. Knucklewalking seems to be a compromise, an ability to use the
> forelimbs for locomotion once the structure has been significantly altered
> away from the structure common to many other primates. But there were
> still many things in common with the forelimbs of the knucklewalkers
> (specifically some robusticity in the elbows) and *all* other quadrupeds.
>
> My suspicion is also that we are evolved from a knucklewalker and once
> selection for these traits disappeared, the traits likewise disappeared,
> the most conspicuous disappearing first.
A suspicion not backed up by any facts, though.
> What bothers me about your "gradual" scenario is two fold: a) we don't see
> the gradual appearance of knucklewalking traits and we don't see any
> signs of any quadrupedalism. We see a particular
> trait that's there for a million years totally unpaired with any signs of
> quadrupedalism. None. Zero. A notched distal radius is *not* a
> conspicuous sign of using your forelimbs for locomotion at all. There are
> other signs. Why, for a million years, are they totally absent?
If they climbed, waded and used knuckles for support when getting out
of water or making the odd postural step on the ground then we
wouldn't expect to see much sign of quadrupedalism would we? A notched
distal radii - in my most humble opinion - is more likelt to have had
some function than no function at all if it remained for one million
years. If you can think of a function other than - some kind of
short-term supporting role - perhaps whilst feeding from water-side
sedges - then I'm open to it. But I'm not open to the idea that it was
'nothing but a vestigial trait from a previous, hypothetical full
knuckle-walker.' If it was some kind of basic support role - perhaps
for feeding - then this is exactly the kind of way a gradual
appearance of knuckle-walking would evolve.
> We do, however, in these creatures, see clear signs of *bipedalism.*
Yes but was it terrestrial bipedalism or wading bipedalism? You
*assume* terrestrial, I don't.
> >> So your totally depending on a rare trait (the notch) being something
> >> necessary for tiny amounts of time, selected for quickly, but the more
> >> universal traits seen in quadrupeds don't develop so quickly such that
> >> limited time quadrupedally results in nothing? Do you not see the problem
> >> with this?
> >
> >Not really.
>
> Obviously you don't. I wish you luck trying to publish. The specialists
> are going to eat you alive.
Maybe the specialists would be able to tell me on what basis they
assumed the LCA was a knuckle-walker and how those traits evolved.
> >> It's a bony growth which (to the best of our knowledge) didn't do anything
> >> in A.afarensis or A.anamensis but does serve as a PART of a complete
> >> knucklewalking complex.
> >>
> >> It might reduce flexibility of the wrist in the trees, but please admit
> >> you have no data to confirm this.
> >
> >I admit I have no data but it's still likely to be true. A bony notch
> >'designed' to restrict the movement of the wrist whilst k-w-ing is
> >likely to restrict the movement in trees too isn't it?
>
>
> I'm...sorry...difficult...to...type...over...laughter...
> Must...not...stop...breathing!
>
> I'm saving this one: "I admit I have no data but it's still more likely
> to be true." -Algis
>
> If that doesn't sum up your argument, I don't know what does. This is why
> I accuse you of doing pseudoscience. You are not doing data analysis.
> You don't even have any data. You're working on your hunch and concluding
> it must be so.
I meant I don't have a reference, a citation to back it up. Can you
quote me one that backs up your view that the notches would have no
effect on their locomotion? There hasn't been an infinite amount of
research done on which to draw from. There is much - a vast majority -
which has not been studied and on which we can only postulate on
logically.
So, if you've stopped laughing, can you tell me why it is illogical to
assume that a notch on the end of the radius, whose function seems to
be pretty much only keeping the wrist locked during knuckle-walking,
would be expected to have no effect on the movement of the wrist
whilst the animal is climbing a tree? Because if you can't, and if
you might even then have begun to doubt that idea yourself, you should
then question why this thing remained 'vestigial' for one million
years.
> >> I'm curious why you say it was using energy. It's more difficult for the
> >> bone to develop the notch than not to? So much energy as to be
> >> selectively disadvantageous? Please admit that here too you have no data
> >> to support this proposition.
> >
> >I admit I have no data but it's still likely to be true. Just basic
> >skeletal biology really, Jason. Every notch that has function has to
> >be actively maintained. If it had no function it would have atrophied.
> >You do know about how bone gets recycled, don't you?
>
> See above:
> "I admit I have no data but it's still more likely
> to be true." -Algis
>
> All notches have to have a function? Really? I'm curious where you get
> this. My forensic osteo friends would take issue with this, as would my
> functional anatomy friends. It's exactly those bizarre notches and
> grooves that are their bread and butter.
Ok. Notches that remain pretty much morphologically distinct for a
million years must have a function. Ask your osteo collegues what they
think about the vestigial idea. Please tell me what they say.
> >> >The plasticity of bone, the way they develop, the way that bony tissue
> >> >is recycled and is under constant review by body stresses in a single
> >> >lifetime is inconsistent with the view that a notch on a bone would
> >> >remain unchanged, without any function, for one million years.
> >>
> >> Again, your pronouncement. I have my doubts that you know enough about
> >> the subject to say this with any certainty.
> >
> >And I'm beginning to have my doubts that you know as much about this
> >as you'd like me to believe.
>
> Have your doubts. I don't care. I'm confident in what I know and what I
> don't know.
>
> "I admit I have no data but it's still more likely to be true." -Algis
I'm confident in what I know and don't know too. Plus, I'm happy to
admit my ignorance when it exists. I have no reputation to protect and
no peers looking over my shoulder to worry about. If I'm wrong to be
sceptical about this vestigial idea then show me how.
> >Of course not. Why does the lack of fossil evidence stretch the
> >credibility of the vestigial argument? Because you have no data
> >whatsoever on which to base the assumption that any such type of
> >locomotion happenend before.
>
> I have no *fossil* data. On the other hand, there's considerable
> comparative data suggesting that the trait wasn't functional.
That's just based on your interpretation, your *assumption* that they
were terrestrial bipeds. They may not have been.
> There's
> considerable phylogenetic data that suggests it wasn't developing. You
> seem to want to ignore this.
What phyloegentic data that it wasn't developing.
Timeline
-7mya---6mya---5mya---4mya---3mya---2mya---1mya---Present
No evidence of k-w
Some evidence of k-w
Apes k-w
... and yet you want to posit...
Timeline
-7mya---6mya---5mya---4mya---3mya---2mya---1mya---Present
k-w-er Apes k-w
vestigial k-w
> >It's odd - we have evidence that the LCA might have been bipedal
> >(Orrorin & Sahelanthropus both may have preceded the LCA according to
> >some interpretations of the molecular data) but we have no evidence at
> >all that the LCA was a knuckle-walker. And yet you *choose to believe*
> >the later even to the extent that you have to cast further serious
> >doubts on the very essence of the molecular data to accomodate that
> >view.
>
> Again, you're confusing no fossil data with no data. Seriously confusing
> it. There's evidence that the LCA was a knucklewalker, evidence derived
> from morphological studies of extant apes and humans and studies of the
> fossil remains of extinct hominids. Please stop saying that there's no
> data as if I was making this up.
Ok - give me a clue about this evidence. Where might I find it?
> >You keep playing that tape recording about how your model makes more
> >phylogenetic sense but the more I think about it the less
> >evidence-based it is. I think you are just trying to pull the wool
> >over my eyes and failing badly.
>
> Fine. Believe what you want.
>
> But if you want anyone to accept your curious take on phylogeny, please do
> be prepared to explain how you see convergence in the cranial morphology
> within apiths and Homo to the exclusion of the extant apes and the
> postcranial morphology of apiths and Homo to the exclusion of extant apes.
> We see these things. Honest.
Placing a'piths is difficult. I don't think anyone is sure if they're
ancestral to Pan/Gorilla but that seems to me to be just as likely the
idea that they're ancestral to Homo. More likely neither.
> >So - either it's a fully quadrupedal fully-weight-baring
> >knuckle-walker or it's not. Black or White. On or Off. How on earth do
> >you teach anything to do with evolution? Are you a creationist in
> >disguise?
>
> Hey, Algis, the creationist slander will only make you look bad. If
> you're just trying to be pissy, fuck off and die. Come back once you've
> actually learned something. If you really think you're winning points,
> I'm confident in my ability to teach evolutionary biology because I've got
> a good track record doing it. You can say the same?
Gosh. Please don't be so sensitive. It was kind-of a joke. I'm sorry
if I offended you. I certainly didn't mean it as *slander*. Get a
life. Get a sense of humour, please.
> Again, for the umteenth time: there are ZERO characteristics of apiths
> that are part of the common suite found in ALL quadrupeds related to
> quadrupedalism. While it may be that there are shades between in an
> idealized case, right here, with this real data there is not evidence that
> we're not at a zero-level quadrupedalism.
But I'm not arguing they were quadrupeds - for the (umpteen + 1)th
time. I (think) you put in an extra 'not' in there. I think that is
exactly what the evidence shows - at leats it is a reasonable
interpretation of the data.
> >> We have no clear evidence that humans are adapted (this word have a real
> >> meaning) for being aquatic. We have a hodgepodge with internal
> >> inconsistencies.
> >
> >We swim better than chimps and we are clearly, blatently obviously
> >more adapted to moving through water than they are. What more evidence
> >do you need?
>
> We're clearly better able to swim than chimps. You are inferring that the
> difference is adaptive. Differences are not necessarily all adaptive.
Not necessarily but very likely. Chimps are better at moving through
trees than we are - no-one would doubt that that was adaptive - or,
more precisely that our loss of ability there is due to a loss of
those adaptations. So, why when it comes to just another way of moving
- through water - do you need to invoke mysterious forces which have
nothing to do with evolution?
It's just another example of the double standards you seem to have.
One for your mainstream stuff and another for that which you judge to
be pseudoscience.
Algis Kuliukas
Jim McGinn
> > Features evolve slowly.
>
> That is a major point of contention in evolutionary biology.
Point of contention? It really isn't contended. If
it can be said to be contended at all the contest is
between those that know the facts (features evolve
rapidly) and those that are ignorant (out of date) of
the facts and effectively ignore the issue with
dismissive comments like, "That is a major point of
contention in evolutionary biology."
> Some
> features appear not to evolve slowly but sprout up all at once. Whether or
> not this is indicative of the way the traits evolve or simply a product of
> the fossil record keeping is unclear, but it's not clear that a feature
> must evolve slowly. Highly selectively advantageous traits do seem to
> burst on the scene in short order.
Right.
Jim
Jason Eshleman
Algis Kuliukas <al...@RiverApes.com> wrote:
>j...@veni.ucdavis.edu (Jason Eshleman) wrote in message news:<ba11ps$1e4$1...@woodrow.ucdavis.edu>...
>> Algis Kuliukas <al...@RiverApes.com> wrote:
>
>> >Features evolve slowly.
>>
>> That is a major point of contention in evolutionary biology. Some
>> features appear not to evolve slowly but sprout up all at once. Whether or
>> not this is indicative of the way the traits evolve or simply a product of
>> the fossil record keeping is unclear, but it's not clear that a feature
>> must evolve slowly. Highly selectively advantageous traits do seem to
>> burst on the scene in short order.
>>
>> >There must have been a transitional stage when
>> >a brachiating (or wading) ape first started getting down on all fours.
>>
>> Yes, but for how long this transition would have persisted is unclear.
>> Currently, the notched radii shows up for a million years (in A.anamensis
>> through late A.afarensis) with no signs of morphological modification. It
>> does not look like a knucklewalking complex is developing over this
>> period.
>
>If you assume that they were terrestrial bipeds of course it could be
>interpreted to look that way. If you assume that they were wading apes
>then I think it's the best interpretation.
You keep harping on the assumption of a terrestrial biped. That's totally
irrelevent. Whether the creature was terrestrial, arboreal, or was
whisked away by ferries, it doesn't show any signs of using its forelimbs
for support. I realize it's comforting to try to ignore my argument by
saying that it's all based on the assumption of a terrestrial biped. It's
not. It's based on the morphological evidence that the forelimbs weren't
being used for support. Not at all.
If they were wading apes, they still weren't using their arms for support.
You're probably going to say something about how water gives more support
ergo less stress, but at the point you'd have them knucklewalking, they'd
be out of the water and thus have no aid from the water. None, zero,
zilch.
Your model of the "sort of" knucklewalker simply doesn't match the
evidence. Were you honest about this, you'd abandone it.
You don't see intermediates in many things. Though (and this is largely
suspicion based on the way he asks questions at meetings) perhaps Tim
White will shock us soon with a A.ramidus paper showing a nice transition,
we don't see much in the way of a transition to bipedality either.
The fossil record is incomplete. Change doesn't appear to occur so slowly
at all times as to leave a nice record. It's unfortunate, but it's hardly
cause to try to make the square peg fit into the round hole.
>I agree that often evolution *appears* to work rapidly. And yes this
>could just be through gaps in the fossil record. But here we have
>evidence that might be interpretted as showing a definite evolutionary
>trend - with clear intermedites and no need for saltatory leaps.
Except that the trait *isn't* transitional. There's ZERO evidence that
this trait functioned to make A.afarensis any more of a knucklewalker than
you or I. That it TOTALLY lacked those traits seen in EVERY quadruped
is reason to reject that they were quadrupedal, even in the gray area of
quadrupedalism.
>Taking the same brachiating ancestral starting point we can have a
>smooth transition from that to aquarboreality - a climbing/wading ape
>which moves in an upright way. From there a slight move towards
>terrestriality with some k-w-ing coming in (A'piths) and more coming
>in with Pan/Gorilla.
Except, again, there's stong evidence that the Apiths were not
knucklewalking, not at all. There's also signficant evidence that the
apith lineage wasn't ancestral to extant knucklewalkers. Very strong
evidence.
>> The sense is that A.afarensis has many derived traits shared with Homo
>> that are not shared with Pan or Gorilla, making it exceedingly unlikely
>> that it is ancestral to the latter pair.
>>
>> >It seems to me we have the following evidence for knuckle-walking
>> >
>> >3.5my A. afarensis (mild)
>>
>> Sorry, I've got to correct you. We've got A.anamesis (4.2) with the same
>> trait as A.afarensis. Further your characterization of the evidence for
>> knucklewalking isn't "mild." It's almost completely non-existant.
>> There's considerable evidence that they didn't use their forelimbs for
>> support, not at all.
>
>Ok. thanks I forgot about the lake hominid. 'Mild' was shorthand for
>'something that might, if you are completely crazy and don't just take
>the opinions of others without questioning them as true, be a
>reasonable alternative explanation.'
^^^^^^^^^^^
you misspelled "unreasonable."
>> >Extant Pan/Gorilla (strong)
>> >Extant Homo (no k-w)
>> >
>> >and that's it. Not much, I know.
>> >
>> >From that you infer...
>> >
>> >Prev (brach.) -----LCA (k-w) ----- Pan/Gorilla (k-w)
>> > \
>> > \
>> > A.pith (vestigial k-w)
>> > \
>> > --------Homo (gone)
>> >
>> >
>> >It seems to me to be more parsimoniuos to assume this...
>> >
>> > --------------------------- Pan/Gorilla (k-w)
>> > /
>> > /
>> >LCA -------A.pith (mild k-w)------ + (extinct)
>> > \
>> > \
>> > --------------------------- Homo (no k-w)
>>
>> I'm not sure what you mean by parsimonious here. You're ignoring the
>> suite of derived traits that unite Homo and apiths. And again, you're
>> ignoring that there is substantial evidence that Apiths didn't
>> knucklewalk.
>
>> You'll have to explain again what you mean by parsimony. I don't think
>> you are using it in the same sense as an evolutionary biologist.
>
>I meant less changes necessary to make the model fit. I thought that
>was what these phylogenetic studies of characters were all about.
It doesn't take less changes. It takes just as many changes in the
knucklewalking trait, and far far more in other morphological traits.
>My model... (looking only at k-w-ing traits)
>> > -(1)------------------------- Pan/Gorilla (k-w)
>> > /
>> > /
>> >LCA -----(1) A.pith (mild k-w)------ + (extinct)
>> > \
>> > \
>> > --------------------------- Homo (no k-w)
>
>- 2 changes...
>
>>
>> Most realistic is
>>
>> /------------------------------extant African Apes
>> /
>> (1) --LCA(knucklewalker)
>> \_(1)__(vestig of KW)_________________________apiths
>> (1)
>> \_(lost vestig)_______________________Homo
>
>3 changes
>
>Perhaps I have completely misunderstood the concept but I think that
>makes your model less parsimonious.
I suspect you have misunderstood the concept. Your model has the
development of full knucklewalking in the ape lineage, of a trait in
another lineage. My model has the development of full knucklewalking at
the LCA, the gradual loss of it in the hominin line. Same number of
evolutionary changes.
What your model ignores is that the phylogeny isn't created solely by
looking at a particular trait. Your model doesn't explain the abundant
sharing of traits in apiths and Homo not seen in the apes, traits for
which apes share a primitive hominoid or even a primitive catarrhine
characteristic and are thus highly likely to be derived for the hominins.
>> With apiths as a sister taxa (if not actually ancestral) to Homo.
>
>> This explains the *derived* characteristics of apiths and Homo and
>> minimizes convergence and duplicate character evolution. Your scenario
>> doesn't account for anything other than knucklewalking.
>
>... but your model conveniently ignores the step for how k-w-ing came
>in. You just assume that was the starting point. Assuming a somewhat
>bipedal starting point (e.g. climber-wader) the whole model is more
>parsimonios, as I understand it.
My model only says that it happened prior to the LCA, that it's primitive
for the African clade of hominoids. That's not ignoring it any more than
you're ignoring how bipedality came in by assuming *It* as the starting
point. The problem with your starting point is that extant apes don't
show *any* signs that they were ever even slightly more bipedal. On the
contrary, there's some evidence that we may have been knuckle walkers in
the past. The evidence isn't overwhelming, but unlike the case with the
bipedal apes, it actually exists.
>> >> Are you at all bothered by the fact that we don't have any signs of
>> >> *later* knucklewalkers who are more adapted to knucklewalking than simply
>> >> having the notched distal radii? Nothing from 3 million years until
>> >> extant apes. I'm curious why it seems you're bothered by the lack of
>> >> really old stuff but seemingly less bothered by the lack of stuff between
>> >> 3 million years and now.
>> >
>> >We only have three bits of evidence: Extant k-w-ers, Extant
>> >non-k-w-ers and 3.5my with some k-w traits. It seems to me to be less
>> >parsimonious to assume that the k-w-ing was going on before (7-8mya?),
>> >have no evidence for that, or earlier evolution of it and then to
>> >assume that some kept it and some lost it rather than to assume that
>> >only the extant apes ever really had (have) it and the 3.5mya evidence
>> >indicates it evolving.
>>
>> You're taking absense of evidence to mean an evidence of absense.
>> That's sketchy, real sketchy.
>
>Well, it's an argument the aquasceptics use all the time against the
>AAH.
>On what basis do you assume the LCA was already a full knuckle-walker
>if there is no fossil evidence whatsoever to back that view up? Other
>than, of course, 'because I think it makes my model work better.'
ON the basis of parsimony. On the basis that there are some
characteristics apparently related to knucklewalking that unite humans,
chimps, and gorillas. On the basis that extinct hominins, with DERIVED
traits relating to both bipedality and DERIVED traits of the teeth and
skull who show a trait that could be a vestigial remnant of knucklewalking
without *any* signs that they actually knucklewalked. On this basis, a
knucklewalker as the LCA of P-G-H is parsimonious, fits with the
phylogeny, and doesn't require abundant homoplasy in locomotive and dental
characteristics. Your model requires far far far more homoplasy
throughout the body. I'm sorry your not bothered by this.
>> Futher, accepting your scenario means
>> accepting that something that doesn't show any real signs of
>> quadrupedalism was somehow a very limited quadruped for about a million
>> years. Your position is really rather untenable with the current data.
>
>If the earliest bipeds were waders and A'piths were too then it makes
>perfect sense.
No, it DOESN'T make perfect sense, Algis. I realize you'll retort
something about how I'm saying that everyone should just take my authority
on this, but trust me when I say it doesn't make sense, not to me, not to
anyone with advanced training in biological anthropology. Whether or not
apiths waded doesn't change that their forelimbs don't show even hints
that they were used to bear the weight of the animal. That's something
you seem to be ignoring time and time again.
>> And of course why you need apiths to be part time quadrupeds from 4 to 3
>> million years is TOTALLY beyond me. They were very capable of terrestrial
>> bipedalism. This seems abundantly clear from both their morphology and
>> the fact that we have tracks made by a biped during this period.
>
>Yes it looks like a contradiction. They have traits that appear to
>make them bipeds, they have traits that appear to make them somewhat
>arboreal and they have traits that appear (ok, to some) to make them
>some kind of knuckle-walkers too. I can see why it's beyond you:
>Because you *assume* they were terrestrial bipeds. I agree it doesn't
>make sense that they'd be part-time quadrupeds if they were also
>terrestrial bipeds. The contradictions are effortless removed, hoever,
>if we just assume instead that the ir bipedalism was mainly for
>wading. Three modes of locomotion for three different substrates.
STOP TELLING ME WHAT I ASSUME! You can't read minds, Algis. There's
nothing in my reasoning that relies on the assumption of a terrestrial
biped. I'm relying on the only the fact that there's no signs that they
were even part time quadrupeds. That's not an assumption, that's what the
evidence shows. You seem not to want to accept this. You seem to want to
insulate yourself from this reality by hiding behind the wall and making
up a scenario whereby it's my preconceived notions that are the problem,
but you're wrong here too.
We see evidence of bipedality on land in apiths. We see evidence of some
arboreality. We see no evidence of any quadrupedality. Whether or not
there was any wading doesn't bear on this at all. If they waded, it still
doesn't change the fact that there's currently solid evidence that they
were even SLIGHTLY quadrupedal.
>> And again, I take extreme issue with your use of the word "parsimony." You
>> are not using it in the sense that evolutionary biologists take it to
>> mean.
>
>I take it to mean - less evolutionary changes required to make the
>model fit.
That's what it means. But your model isn't parsimonious.
>> You seem to take issue with some lineages keeping a trait while other
>> branches lose it. Yet this is EXACTLY what happens in evolution. I'm
>> curious again why you have problems with it. You have some rather
>> pronounced bones to pick (pun intended) with some rather basic concepts in
>> evolutionary biology it would seem.
>
>No I don't. I have issues with you just assuming, as a convenient
>starting point, that knuckle-walking traits had already, magically,
>appeared so that your model works - even though there is no fossil
>evidence for it.
Not magically, but prior to the LCA. I'm sure that it was a result of
standard, non-magical evolutionary forces.
There's no fossil evidence for many things. This doesn't provide you with
free license to take data that pretty clearly shows that something wasn't
a quadruped and saying that it was.
>> >> >But your shoulder explanation is just opinion too. How do you know it
>> >> >wasn't selected for to help swimming?
>> >>
>> >> A strange adaptation then, as shoulders create huge amounts of drag and is
>> >> totally like the shoulder of any other swimming animal. That's not
>> >> opinion. I don't know that it wasn't selected for in swimming, but I do
>> >> know that the the human shoulder (actually an ape brachiating shoulder)
>> >> doesn't seem at all associated with swimming. That's not opinion either.
>> >
>> >Humans, you may have noticed, use their shoulders to swim. We are
>> >better swimmers than other primates (esp. chimps) so the point you
>> >make here is just wishful thinking. The idea that the morphology of a
>> >human shoulder is a vestigial remnant of some brachiating past what
>> >some 15mya is just crazy. Yes, I know. Personal incredulity squared.
>>
>> On the contrary Algis, you're simply wrong.
>
>I might well be wrong. No, I probably am wrong. I've not studied the
>shoulder much at all. I accept all I have is personal incredulity.
>But..
>So, no evolutionary pressure has come to bear on the morphology of not
>only our shoulder but that of all the extant great apes too? They've
>just remained vestigial from their brachiating ancestor? Come off it.
>Any similarities in extant apes are clearly due to the pressence of
>similar pressures - ie climbing.
And so the similarities between extant apes and humans are because humans
climb too?
How much climbing do gorillas do?
>> Our shoulder morphology is virtually identical to the morphology of a
>> gibbon, an chimp, a gorilla, an orang. The parsimonious explanation (and
>> I'm using this term in the sense of an evolutionary biologist), knowing
>> that all five genera are closely related, is that this virtually identical
>> morphology is inherited from a common ancestor. Whether or not it's still
>> of use in the various lineages is a different matter, but it's quite
>> clearly a brachiationist's shoulder. The convergence with Platyrrhini
>> brachiators indicates this further.
>
>... based on a brachiator's shoulder, granted. But - seeing we have
>not been very arboreal for about 3mya - one that has been exposed to
>and shaped by alternative forces since then. They're vestigial only in
>the sense that if the body can make full use of an inherited feature
>without modification it will.
So what exactly are you saying would have happened to the shoulder if we
weren't climbing and weren't swimming. Algis, you're really difficult to
follow here. You seem to be saying that without a near constant
evolutionary pressure, that things would, well, actually, I have no idea
what you're saying. It doesn't make much sense.
>> Could it be that some swimming stroke served to maintain selection on our
>> shoulder? Possibly, but why then do Gorillas (who are very largely
>> terrestrial) similarly maintain the shoulder? It's a handicap in
>> quadrupedal locomotion, necessitating an otherwise cumbersome form of
>> locomotion. Do they too maintain vestige because it's actually being used
>> for something? For what?
>>
>> You're more than incredulous here, Algis. You're just making stuff up.
>
>I wouldn't go that far!
I would.
>> My suspicion is that some of the apes got big and as a consequence, spent
>> more time on the ground out of necessity. I am not sure why, but getting
>> big seems to be one of those things that can happen in a lineage. It's
>> happened over and over in other lineages. Being on the ground, you'd
>> expect some need to get around on the ground. Having the handicap of a
>> brachiationist's shoulder, a more generalized quadrupedal gait wasn't
>> possible. Knucklewalking seems to be a compromise, an ability to use the
>> forelimbs for locomotion once the structure has been significantly altered
>> away from the structure common to many other primates. But there were
>> still many things in common with the forelimbs of the knucklewalkers
>> (specifically some robusticity in the elbows) and *all* other quadrupeds.
>>
>> My suspicion is also that we are evolved from a knucklewalker and once
>> selection for these traits disappeared, the traits likewise disappeared,
>> the most conspicuous disappearing first.
>
>A suspicion not backed up by any facts, though.
Here again you're incorrect. My suspicion is backed by facts. Several
facts actually that I've outlined above. You're hung up on one fact: that
there isn't a fossil record. That's true, but that's not the same as
saying that there's no facts. It is dishonest to say otherwise. Please
do not make me call you a liar by continuing to say that my suspicions
aren't based on any evidence.
>> What bothers me about your "gradual" scenario is two fold: a) we don't see
>> the gradual appearance of knucklewalking traits and we don't see any
>> signs of any quadrupedalism. We see a particular
>> trait that's there for a million years totally unpaired with any signs of
>> quadrupedalism. None. Zero. A notched distal radius is *not* a
>> conspicuous sign of using your forelimbs for locomotion at all. There are
>> other signs. Why, for a million years, are they totally absent?
>If they climbed, waded and used knuckles for support when getting out
>of water or making the odd postural step on the ground then we
>wouldn't expect to see much sign of quadrupedalism would we? A notched
>distal radii - in my most humble opinion - is more likelt to have had
>some function than no function at all if it remained for one million
>years. If you can think of a function other than - some kind of
>short-term supporting role - perhaps whilst feeding from water-side
>sedges - then I'm open to it. But I'm not open to the idea that it was
>'nothing but a vestigial trait from a previous, hypothetical full
>knuckle-walker.' If it was some kind of basic support role - perhaps
>for feeding - then this is exactly the kind of way a gradual
>appearance of knuckle-walking would evolve.
Again, what it seems to come down to is that for some reason, you're
simply incredulous that a particular trait can be vestigial despite the
clear fact that vestigial traits do exist. Please, next time you've got
some time and are at a natural history museum, take a look at the bones
in the flippers of a whale. Please note the similarities between these
and the bones of your own hand. Note how much bone has been "recycled" in
the whale.
I'm sorry you're incredulous. It's going to be a huge handicap for you if
you ever hope to be taken seriously. Again, like it or not, you're going
to find that I'm a pretty good barometer of how others in physical
anthropology will respond, save that I'm taking more time than most
reviewers will, and as this isn't blind, I'm going to be more polite.
You'll do better to stop telling people what they assume, telling people
(erroneously as it were) that they are not basing their conclusions on
fact, creating (rather comically at times) new scenarios to "explain"
things that in fact fail to explain things.
>> We do, however, in these creatures, see clear signs of *bipedalism.*
>
>Yes but was it terrestrial bipedalism or wading bipedalism? You
>*assume* terrestrial, I don't.
LOOK, stop being a shit and telling me what I assume. The morphology fits
with a terrestrial biped. It has the characteristics that would allow for
terrestrial bipedalism as we know it. We have evidence (from tracks) that
creatures engaged in terrestrial bipedalism away from water sources.
Whether or not it was a wading biped is unknown.
>> >> So your totally depending on a rare trait (the notch) being something
>> >> necessary for tiny amounts of time, selected for quickly, but the more
>> >> universal traits seen in quadrupeds don't develop so quickly such that
>> >> limited time quadrupedally results in nothing? Do you not see the problem
>> >> with this?
>> >
>> >Not really.
>>
>> Obviously you don't. I wish you luck trying to publish. The specialists
>> are going to eat you alive.
>
>Maybe the specialists would be able to tell me on what basis they
>assumed the LCA was a knuckle-walker and how those traits evolved.
Maybe you should read some of their papers.
Logic, one way or another, isn't at issue. You are *assuming* that the
notch would have a limiting effect. There's no evidence of this. None.
Do I have evidence that it wouldn't be a problem? Not directly. Though
if you look at an ape wrist you'll see a number of compromises in it
already. Are you familiar with the distal styloid processes in the radius
and ulna? They quite clearly add support in a quadruped. We've got them.
You should be able to find images on line. In our line, they're reduced
relative to a monkey. They don't project so much into the carpal bones
like they do in a monkey. This frees up our wrist for greater mobility,
necessary in a brachiator. The styloid processes no longer serve the
support feature they did in a monkey. Yet they remain. They are not
"recycled" and they don't cause us to have reduced reproductive success.
Clearly they can remain while not serving the original function.
Why did the notches remain vestigial for a million years? Because they
didn't seem to get in the way sufficiently for that time and because when
something's not under selection, it only disappears due to drift or until
another selective pressure knocks it out. You seem to be assuming that
the notch was a big deal, that, if not maintained by selection, it would
have been a significant detriment. That's not supported by anything more
than your conjecture, your nebulous notions of "bone recycling" aside.
>> >> I'm curious why you say it was using energy. It's more difficult for the
>> >> bone to develop the notch than not to? So much energy as to be
>> >> selectively disadvantageous? Please admit that here too you have no data
>> >> to support this proposition.
>> >
>> >I admit I have no data but it's still likely to be true. Just basic
>> >skeletal biology really, Jason. Every notch that has function has to
>> >be actively maintained. If it had no function it would have atrophied.
>> >You do know about how bone gets recycled, don't you?
>>
>> See above:
>> "I admit I have no data but it's still more likely
>> to be true." -Algis
>>
>> All notches have to have a function? Really? I'm curious where you get
>> this. My forensic osteo friends would take issue with this, as would my
>> functional anatomy friends. It's exactly those bizarre notches and
>> grooves that are their bread and butter.
>
>Ok. Notches that remain pretty much morphologically distinct for a
>million years must have a function. Ask your osteo collegues what they
>think about the vestigial idea. Please tell me what they say.
NO. Notches that remain pretty much morphologically distinct for a
million years DO NOT need to have a function. We're stuck here again.
You're hung up on something that's not true.
I have asked my osteo colleagues about it. They've got no problems with it
being a vestigial trait. In fact one has published commentary saying
exactly as much. You poo-pooed that paper for reasons that seem not
entirely clear other than that you said you didn't buy it.
>> >> >The plasticity of bone, the way they develop, the way that bony tissue
>> >> >is recycled and is under constant review by body stresses in a single
>> >> >lifetime is inconsistent with the view that a notch on a bone would
>> >> >remain unchanged, without any function, for one million years.
>> >>
>> >> Again, your pronouncement. I have my doubts that you know enough about
>> >> the subject to say this with any certainty.
>> >
>> >And I'm beginning to have my doubts that you know as much about this
>> >as you'd like me to believe.
>>
>> Have your doubts. I don't care. I'm confident in what I know and what I
>> don't know.
>>
>> "I admit I have no data but it's still more likely to be true." -Algis
>
>I'm confident in what I know and don't know too. Plus, I'm happy to
>admit my ignorance when it exists. I have no reputation to protect and
>no peers looking over my shoulder to worry about. If I'm wrong to be
>sceptical about this vestigial idea then show me how.
You're going to have to take that leap yourself.
>> >Of course not. Why does the lack of fossil evidence stretch the
>> >credibility of the vestigial argument? Because you have no data
>> >whatsoever on which to base the assumption that any such type of
>> >locomotion happenend before.
>>
>> I have no *fossil* data. On the other hand, there's considerable
>> comparative data suggesting that the trait wasn't functional.
>
>That's just based on your interpretation, your *assumption* that they
>were terrestrial bipeds. They may not have been.
OK, I'm tired of being polite you ignorant shit. Stop telling me what my
assumptions are as if I'm making things up. Stop acting just like the
rest of the pseudoscience fruitcakes.
>> There's
>> considerable phylogenetic data that suggests it wasn't developing. You
>> seem to want to ignore this.
>
>What phyloegentic data that it wasn't developing.
>
>Timeline
>-7mya---6mya---5mya---4mya---3mya---2mya---1mya---Present
>
>No evidence of k-w
> Some evidence of k-w
You misspelled "evidence of a trait, but no evidence of knucklewalking"
> Apes k-w
>
>... and yet you want to posit...
>
>Timeline
>-7mya---6mya---5mya---4mya---3mya---2mya---1mya---Present
>
>k-w-er Apes k-w
> vestigial k-w
>
Yes, that's what I want to say. It's the interpretation that fits with
the phylogenetic and comparative evidence and doesn't have contradictions
in the fossil evidence. You're proposing a scenario that contradicts
phylogenetic evidence and comparative evidence.
>
>> >It's odd - we have evidence that the LCA might have been bipedal
>> >(Orrorin & Sahelanthropus both may have preceded the LCA according to
>> >some interpretations of the molecular data) but we have no evidence at
>> >all that the LCA was a knuckle-walker. And yet you *choose to believe*
>> >the later even to the extent that you have to cast further serious
>> >doubts on the very essence of the molecular data to accomodate that
>> >view.
>>
>> Again, you're confusing no fossil data with no data. Seriously confusing
>> it. There's evidence that the LCA was a knucklewalker, evidence derived
>> from morphological studies of extant apes and humans and studies of the
>> fossil remains of extinct hominids. Please stop saying that there's no
>> data as if I was making this up.
>
>Ok - give me a clue about this evidence. Where might I find it?
Sigh. Several months ago I provided you with references of studies on
knucklewalkers. Did you ever bother to read any of those? Please, and I
realize I'm sounding somewhat like Marc here, but why should I bother
looking things up again when I've seen ZERO evidence from you that you're
willing to consider things? Why, when what inevitably happens is you
accuse me of making assumptions as if I'm making things up, should I try
to force your fingers out of your ears? Algis, you don't act like someone
who is at all interested in trying to falsify your ideas. From my
vantage, you seem like you're intent on insulating your ego from
substantive attacks on your pet hypotheses. I'm tired of wasting my time
if you're going to continue to act like a shit in return.
You apparently have a master's degree. You should know how to use a
biological reference search engine. Finding papers discussing the
evolution of knucklewalking isn't hard. I'm tired of holding your hand.
>> >You keep playing that tape recording about how your model makes more
>> >phylogenetic sense but the more I think about it the less
>> >evidence-based it is. I think you are just trying to pull the wool
>> >over my eyes and failing badly.
>>
>> Fine. Believe what you want.
>>
>> But if you want anyone to accept your curious take on phylogeny, please do
>> be prepared to explain how you see convergence in the cranial morphology
>> within apiths and Homo to the exclusion of the extant apes and the
>> postcranial morphology of apiths and Homo to the exclusion of extant apes.
>> We see these things. Honest.
>
>Placing a'piths is difficult. I don't think anyone is sure if they're
>ancestral to Pan/Gorilla but that seems to me to be just as likely the
>idea that they're ancestral to Homo. More likely neither.
No, less likely, for a number of reasons. Apiths shared *derived* cranial
and dental characteristics with Homo where apes retain the ancestral
catarrhine form. You have to have a reversal of several characteristics
(including, but not limited to: the reduction and elimination of a honing
complex, the addition of a second p3 cusp, absolute canine reduction, more
forward placement of the foramen magnum, shortened cranial base, increased
cranial flexion) if you accept apiths as ancestral to Gorilla or Pan.
Note that these are characteristics that are *independent* of the
postcrania, which likewise shows derived traits relative to bipedalism
where apes retain a primitive form.
That apiths weren't directly ancestral to humans is quite likely. That
they're in a clade with humans with the African apes as an outgroup, that
we share a more recent common ancestor with apiths than with apes is in
fact far more parsimonious than apiths being ancestral to apes or a
trichotomy with the three.
You have a master's in physical anthropology, no? Quite frankly, I'm
shocked that you could have received this degree without being aware of
this.
>> >So - either it's a fully quadrupedal fully-weight-baring
>> >knuckle-walker or it's not. Black or White. On or Off. How on earth do
>> >you teach anything to do with evolution? Are you a creationist in
>> >disguise?
>>
>> Hey, Algis, the creationist slander will only make you look bad. If
>> you're just trying to be pissy, fuck off and die. Come back once you've
>> actually learned something. If you really think you're winning points,
>> I'm confident in my ability to teach evolutionary biology because I've got
>> a good track record doing it. You can say the same?
>
>Gosh. Please don't be so sensitive. It was kind-of a joke. I'm sorry
>if I offended you. I certainly didn't mean it as *slander*. Get a
>life. Get a sense of humour, please.
It doesn't seem like humor. It seems like you'd run out of anything
substantive to say and decided to pull the creationist line. The attack
on my teaching was just plain rude. I don't know what you do for a
living, but I don't think I've ever questioned what you do. [note if
you're still trying to figure it out: teaching physical anthropology is
what pays my bills.]
>> Again, for the umteenth time: there are ZERO characteristics of apiths
>> that are part of the common suite found in ALL quadrupeds related to
>> quadrupedalism. While it may be that there are shades between in an
>> idealized case, right here, with this real data there is not evidence that
>> we're not at a zero-level quadrupedalism.
>
>But I'm not arguing they were quadrupeds - for the (umpteen + 1)th
>time. I (think) you put in an extra 'not' in there. I think that is
>exactly what the evidence shows - at leats it is a reasonable
>interpretation of the data.
The evidence indicates apiths to be zero level quadrupeds. I stand by
this.
>> >> We have no clear evidence that humans are adapted (this word have a real
>> >> meaning) for being aquatic. We have a hodgepodge with internal
>> >> inconsistencies.
>> >
>> >We swim better than chimps and we are clearly, blatently obviously
>> >more adapted to moving through water than they are. What more evidence
>> >do you need?
>>
>> We're clearly better able to swim than chimps. You are inferring that the
>> difference is adaptive. Differences are not necessarily all adaptive.
>Not necessarily but very likely. Chimps are better at moving through
>trees than we are - no-one would doubt that that was adaptive - or,
>more precisely that our loss of ability there is due to a loss of
>those adaptations. So, why when it comes to just another way of moving
>- through water - do you need to invoke mysterious forces which have
>nothing to do with evolution?
I invoke that you're reading much into it. I invoke that you want to use
water to explain many things that it explains poorly or explains only by
contradicting things that are better explained in other ways. There's no
evidence that a common ancestor of humans was ever committed to needing to
swim such that it resulted in any of the characteristics you say would
have resulted from needing to swim and further those characteristics that
you say are clearly the result of swimming pressure don't appear to me to
be consistent with such a pressure.
>It's just another example of the double standards you seem to have.
>One for your mainstream stuff and another for that which you judge to
>be pseudoscience.
Believe what you want.
Algis Kuliukas
> >If you assume that they were terrestrial bipeds of course it could be
> >interpreted to look that way. If you assume that they were wading apes
> >then I think it's the best interpretation.
>
> You keep harping on the assumption of a terrestrial biped. That's totally
> irrelevent. Whether the creature was terrestrial, arboreal, or was
> whisked away by ferries, it doesn't show any signs of using its forelimbs
> for support. I realize it's comforting to try to ignore my argument by
> saying that it's all based on the assumption of a terrestrial biped. It's
> not. It's based on the morphological evidence that the forelimbs weren't
> being used for support. Not at all.
What I meant was that if you assume a'piths were wading bipeds then a
degree of forearm support (whilst feeding on plants on water margins
and for helping get out of the water - both still in a predominently
upright posture) is logical and could explain the presence (and even
the evolution of) of some of the knuckle-walking traits we see in
Pan/Gorilla. Note this is not arguing that they were quadrupedal or
that they were knuckle-walkers. I know you find this incredible but I
still don't see why.
I'm sorry if I irritate you by describing your position as one based
"on the assumption of a terrestrial biped" but, to be fair, that has
been your stated position many times. I'm not making that up. What? So
are you saying that now you don't think that a'piths were terrestrial
bipeds?
Your objection to the 'notches as evidence for some kind of support'
idea seems to be that they had no other structures for weight bearing.
I know that. But I am not arguing that they were knuckle-walkers, just
that this trait might be explained as some early manifestation of
forearm support whilst still upright.
> If they were wading apes, they still weren't using their arms for support.
Sometimes they might have. Whilst feeding, whilst climbing out of the
water.
> You're probably going to say something about how water gives more support
> ergo less stress, but at the point you'd have them knucklewalking, they'd
> be out of the water and thus have no aid from the water. None, zero,
> zilch.
You always have to put it in black and white terms, don't you? Either
they were in the water or they were on land or they were in trees.
What if they moved arounf the edge of the water. This is exactly what
I would expect. When I observed bonobos some spent much of the time in
contact with water hovering from the water's edge to the margin and
back again. This was predominently upright with feet in the water but
with some forearm support too.
On the land-water margin they would get some support from the water
but they'd also need some support on land too. Your black & white view
of the world just isn't sophisticated enough to handle this, I know,
but you really need to try harder to accomodate grey areas.
> Your model of the "sort of" knucklewalker simply doesn't match the
> evidence. Were you honest about this, you'd abandone it.
I think it does match the evidence. The way that you have to keep
falling back on the safe, solid ground taht the evidence doesn't show
that they were terrestrial knuckle-walkers - something I fully accept
- indicates to me that you haven't really understood the concept of a
wading ape.
> You don't see intermediates in many things. Though (and this is largely
> suspicion based on the way he asks questions at meetings) perhaps Tim
> White will shock us soon with a A.ramidus paper showing a nice transition,
> we don't see much in the way of a transition to bipedality either.
Do you think this is imminent? Wow? How many years has he been sitting
on this now?
> The fossil record is incomplete. Change doesn't appear to occur so slowly
> at all times as to leave a nice record. It's unfortunate, but it's hardly
> cause to try to make the square peg fit into the round hole.
Fair enough but my point is that if we found fossils of a hominoid arm
that dated at, say, 9my and there were notches on the distal radius
but it lacked other features of extant ape knuckle-walking how would
you interret that? Would you accept it as an early knuckle-walker or
would you dismiss the notches as vestigial from some, still earlier,
knuckle-walker? To be precise: what fossil attributes do you predict
to be evidence of an early knuckle-walker? Weight-bearing ones without
notches, notches without weight-bearing or *must* they both be present
at the same time?
> >I agree that often evolution *appears* to work rapidly. And yes this
> >could just be through gaps in the fossil record. But here we have
> >evidence that might be interpretted as showing a definite evolutionary
> >trend - with clear intermedites and no need for saltatory leaps.
>
> Except that the trait *isn't* transitional. There's ZERO evidence that
> this trait functioned to make A.afarensis any more of a knucklewalker than
> you or I. That it TOTALLY lacked those traits seen in EVERY quadruped
> is reason to reject that they were quadrupedal, even in the gray area of
> quadrupedalism.
But I'M NOT SAYING THEY WERE QUADRUPEDAL!!!! I it was me that had made
that point, you would have started calling me an idiot or twit or made
some other arogant comment about wasting precious time or something.
Please note that I am not doing that. I am incredibly frustrated with
your obstinacy in maintaining an argument that I have refuted a
million times but still, please note, I do not slip into ad hominems.
> >Taking the same brachiating ancestral starting point we can have a
> >smooth transition from that to aquarboreality - a climbing/wading ape
> >which moves in an upright way. From there a slight move towards
> >terrestriality with some k-w-ing coming in (A'piths) and more coming
> >in with Pan/Gorilla.
>
> Except, again, there's stong evidence that the Apiths were not
> knucklewalking, not at all.
I know.
> There's also signficant evidence that the
> apith lineage wasn't ancestral to extant knucklewalkers. Very strong
> evidence.
I'm not saying they were. The model I adopt ceratinly doesn't need
that.
> >Ok. thanks I forgot about the lake hominid. 'Mild' was shorthand for
> >'something that might, if you are completely crazy and don't just take
> >the opinions of others without questioning them as true, be a
> >reasonable alternative explanation.'
>
> ^^^^^^^^^^^
>
> you misspelled "unreasonable."
What is reasonable or unreasonable is a mater of opinion.
> >> You'll have to explain again what you mean by parsimony. I don't think
> >> you are using it in the same sense as an evolutionary biologist.
> >
> >I meant less changes necessary to make the model fit. I thought that
> >was what these phylogenetic studies of characters were all about.
>
> It doesn't take less changes. It takes just as many changes in the
> knucklewalking trait, and far far more in other morphological traits.
Assuming A'piths were *not* ancestral to Pan/Gorilla how can you argue
that there'd be more 'other' morphological changes?
The model below made that assumption.
> >My model... (looking only at k-w-ing traits)
> >> > -(1)------------------------- Pan/Gorilla (k-w)
> >> > /
> >> > /
> >> >LCA -----(1) A.pith (mild k-w)------ + (extinct)
> >> > \
> >> > \
> >> > --------------------------- Homo (no k-w)
> >
> >- 2 changes...
> >> Most realistic is
> >>
> >> /------------------------------extant African Apes
> >> /
> >> (1) --LCA(knucklewalker)
> >> \_(1)__(vestig of KW)_________________________apiths
> >> (1)
> >> \_(lost vestig)_______________________Homo
> >
> >3 changes
> >
> >Perhaps I have completely misunderstood the concept but I think that
> >makes your model less parsimonious.
>
> I suspect you have misunderstood the concept.
Why, thank you Jason.
> Your model has the development of full knucklewalking in the ape lineage, of
> a trait in
> another lineage. My model has the development of full knucklewalking at
> the LCA, the gradual loss of it in the hominin line. Same number of
> evolutionary changes.
Except that my model also accounts for it's evolution, your's does
not: It just assumes it was there from the start, conveniently.
My model: 2 changes; Your model: 3 changes. Therefore mine is more
parsimonious.
> What your model ignores is that the phylogeny isn't created solely by
> looking at a particular trait. Your model doesn't explain the abundant
> sharing of traits in apiths and Homo not seen in the apes, traits for
> which apes share a primitive hominoid or even a primitive catarrhine
> characteristic and are thus highly likely to be derived for the hominins.
Ok, but you know that there are other traits which the a'piths share
with apes too. You gloss over those as if they don't exist. The safest
bet seems to be not to place a'piths abcestral to either Pan, Gorilla
or Homo. If we do that then any similarities between a'pith and homo
and a'piths and apes have to be seen as shared primitive or convergent
characters.
> >... but your model conveniently ignores the step for how k-w-ing came
> >in. You just assume that was the starting point. Assuming a somewhat
> >bipedal starting point (e.g. climber-wader) the whole model is more
> >parsimonios, as I understand it.
>
> My model only says that it happened prior to the LCA, that it's primitive
> for the African clade of hominoids. That's not ignoring it any more than
> you're ignoring how bipedality came in by assuming *It* as the starting
> point.
Granted, but (see below) there is at least some fossil evidence for
that view.
> The problem with your starting point is that extant apes don't
> show *any* signs that they were ever even slightly more bipedal. On the
> contrary, there's some evidence that we may have been knuckle walkers in
> the past. The evidence isn't overwhelming, but unlike the case with the
> bipedal apes, it actually exists.
No actually, there is evidence (Sahelanthropus and Orrorin) of
bipedality very early in the honinoid line which could pre-date the
LCA but there is no evidence of any knuckle-walking hominoids that
could.
A wading-climbing biped could be ancestral to Pan & Gorilla and to
Homo. That is the central point which you are dismissing as
impossible. I disupte your dismissal.
> >> You're taking absense of evidence to mean an evidence of absense.
> >> That's sketchy, real sketchy.
> >
> >Well, it's an argument the aquasceptics use all the time against the
> >AAH.
> >On what basis do you assume the LCA was already a full knuckle-walker
> >if there is no fossil evidence whatsoever to back that view up? Other
> >than, of course, 'because I think it makes my model work better.'
>
> ON the basis of parsimony.
But I demonstrated that the phylogeny assuming a non-k-w-ing LCA was
more parsimonious. (2 changes rather than 3, remember)
> On the basis that there are some
> characteristics apparently related to knucklewalking that unite humans,
> chimps, and gorillas. On the basis that extinct hominins, with DERIVED
> traits relating to both bipedality and DERIVED traits of the teeth and
> skull who show a trait that could be a vestigial remnant of knucklewalking
> without *any* signs that they actually knucklewalked. On this basis, a
> knucklewalker as the LCA of P-G-H is parsimonious, fits with the
> phylogeny, and doesn't require abundant homoplasy in locomotive and dental
> characteristics. Your model requires far far far more homoplasy
> throughout the body. I'm sorry your not bothered by this.
Ok, I accept those points. It's true, I'm not bothered by it. I do
think that many (if not most) such characters are convergent. You seem
to have a belief that bony structures can remain without function for
millions of years. I do not. If you have such a view it tends to place
you in a bit of straight-jacket when analysing phylogenies. The
fundamental question here is whether a wading-climbing biped could be
ancestral to Pan & Gorilla and to Homo. You say: NO, I say YES.
> >> Futher, accepting your scenario means
> >> accepting that something that doesn't show any real signs of
> >> quadrupedalism was somehow a very limited quadruped for about a million
> >> years. Your position is really rather untenable with the current data.
> >
> >If the earliest bipeds were waders and A'piths were too then it makes
> >perfect sense.
>
> No, it DOESN'T make perfect sense, Algis. I realize you'll retort
> something about how I'm saying that everyone should just take my authority
> on this, but trust me when I say it doesn't make sense, not to me, not to
> anyone with advanced training in biological anthropology. Whether or not
> apiths waded doesn't change that their forelimbs don't show even hints
> that they were used to bear the weight of the animal. That's something
> you seem to be ignoring time and time again.
No, you are ignoring the fact the model suggests that they wouldn't be
weight-bearing in the sense that a quadrupedal African ape is.
> >Yes it looks like a contradiction. They have traits that appear to
> >make them bipeds, they have traits that appear to make them somewhat
> >arboreal and they have traits that appear (ok, to some) to make them
> >some kind of knuckle-walkers too. I can see why it's beyond you:
> >Because you *assume* they were terrestrial bipeds. I agree it doesn't
> >make sense that they'd be part-time quadrupeds if they were also
> >terrestrial bipeds. The contradictions are effortless removed, hoever,
> >if we just assume instead that the ir bipedalism was mainly for
> >wading. Three modes of locomotion for three different substrates.
>
> STOP TELLING ME WHAT I ASSUME! You can't read minds, Algis. There's
> nothing in my reasoning that relies on the assumption of a terrestrial
> biped. I'm relying on the only the fact that there's no signs that they
> were even part time quadrupeds. That's not an assumption, that's what the
> evidence shows. You seem not to want to accept this. You seem to want to
> insulate yourself from this reality by hiding behind the wall and making
> up a scenario whereby it's my preconceived notions that are the problem,
> but you're wrong here too.
Tell me: Do you not assume that A'piths were terrestrial bipeds now? I
honestly thought you did. I thought that was your explanation of their
traits, the explanation of our bipedality. I thought you'd made this
clear many times over the years. Do you now say that you ndon't hold
that view?
On the line between full-time biped and full-time quadruped there are
points in between. There must be a point on that line where some
support features, without the full weight-bearing ones, make sense.
K-w-ing must have evolved somehow.
> We see evidence of bipedality on land in apiths.
Sorry to do this but... you *assume* it was land. It might have been
in water.
> We see evidence of some
> arboreality. We see no evidence of any quadrupedality. Whether or not
> there was any wading doesn't bear on this at all. If they waded, it still
> doesn't change the fact that there's currently solid evidence that they
> were even SLIGHTLY quadrupedal.
I think the notches on the distal radii must have had some function -
you think they were useless, just a vestige from the past. I think the
likelihood is that they has some intermediate function that made sense
on the evolution towards knuckle-walking. Support for a wading ape
whilst feeding on marginal sedges or whilst getting out od the water
would seem to be reasonable models for that function.
> >> And again, I take extreme issue with your use of the word "parsimony." You
> >> are not using it in the sense that evolutionary biologists take it to
> >> mean.
> >
> >I take it to mean - less evolutionary changes required to make the
> >model fit.
>
> That's what it means. But your model isn't parsimonious.
2 changes, rather than 3 - that's more parsimonious. Does being a
professional physical anthropologist give you the right to change the
rules to make sure that you are right?
> >No I don't. I have issues with you just assuming, as a convenient
> >starting point, that knuckle-walking traits had already, magically,
> >appeared so that your model works - even though there is no fossil
> >evidence for it.
>
> Not magically, but prior to the LCA. I'm sure that it was a result of
> standard, non-magical evolutionary forces.
>
> There's no fossil evidence for many things. This doesn't provide you with
> free license to take data that pretty clearly shows that something wasn't
> a quadruped and saying that it was.
I'M NOT SAYING THAT A'PITHS WERE QUADRUPEDS.
> >So, no evolutionary pressure has come to bear on the morphology of not
> >only our shoulder but that of all the extant great apes too? They've
> >just remained vestigial from their brachiating ancestor? Come off it.
> >Any similarities in extant apes are clearly due to the pressence of
> >similar pressures - ie climbing.
>
> And so the similarities between extant apes and humans are because humans
> climb too?
No. That's because... Well I suppose it's because the post-arboreal
functions applied to shoulders (ie carrying, throwing, swimming,
diving) were compatible with the inherited structure without major
modification.
> How much climbing do gorillas do?
Quite a bit.
> >... based on a brachiator's shoulder, granted. But - seeing we have
> >not been very arboreal for about 3mya - one that has been exposed to
> >and shaped by alternative forces since then. They're vestigial only in
> >the sense that if the body can make full use of an inherited feature
> >without modification it will.
>
> So what exactly are you saying would have happened to the shoulder if we
> weren't climbing and weren't swimming. Algis, you're really difficult to
> follow here. You seem to be saying that without a near constant
> evolutionary pressure, that things would, well, actually, I have no idea
> what you're saying. It doesn't make much sense.
Mmm.. getting into wierd territory here. If a hominid stopped
climbing, didn't do any swimming and didn't carry things or throw
things? I gues the arms would just atrophy. Put it this way: If having
arms no longer helped the fitness of the animal then they'd be
expected to disappear. Clearly, though, arms are vital to the fitness
of all hominoids and always were. The question then is what function
do those arms perform and is that function possible using the
inherited structure or is some modification necessary? If it's the
former then you'd expect them to remain largely unaltered, if it's the
later then you'd expect them to evolve.
> >> My suspicion is also that we are evolved from a knucklewalker and once
> >> selection for these traits disappeared, the traits likewise disappeared,
> >> the most conspicuous disappearing first.
> >
> >A suspicion not backed up by any facts, though.
>
> Here again you're incorrect. My suspicion is backed by facts. Several
> facts actually that I've outlined above. You're hung up on one fact: that
> there isn't a fossil record. That's true, but that's not the same as
> saying that there's no facts. It is dishonest to say otherwise. Please
> do not make me call you a liar by continuing to say that my suspicions
> aren't based on any evidence.
Ok, so your facts are ...
a) that a'piths lack a set of traits that indicate they were
quadrupedal terrestrial knuckle-walkers
- I agree. You have not really taken on the possibility that there
might exist some intermediate function of radial notches that is not
for knuckle-walking in the accepted sense.
and ...
b) Bony characters of hominoidae indicate a phylogeny of a'piths which
places them in the Homo line and not the pan/gorilla line.
- That is, I think, arguable. I know Charles Oxnard and others would
dispute it. If A'piths are not on the homo line at all then that part
of your evidence has to be discarded.
Which leaves us with the fact that there is fossil evidence that the
LCA might have been bipedal (depending on interpretaions on the
molecular clock) but zero fossil evidence that the LCA might have been
a knuckle-walker.
> >If they climbed, waded and used knuckles for support when getting out
> >of water or making the odd postural step on the ground then we
> >wouldn't expect to see much sign of quadrupedalism would we? A notched
> >distal radii - in my most humble opinion - is more likelt to have had
> >some function than no function at all if it remained for one million
> >years. If you can think of a function other than - some kind of
> >short-term supporting role - perhaps whilst feeding from water-side
> >sedges - then I'm open to it. But I'm not open to the idea that it was
> >'nothing but a vestigial trait from a previous, hypothetical full
> >knuckle-walker.' If it was some kind of basic support role - perhaps
> >for feeding - then this is exactly the kind of way a gradual
> >appearance of knuckle-walking would evolve.
>
> Again, what it seems to come down to is that for some reason, you're
> simply incredulous that a particular trait can be vestigial despite the
> clear fact that vestigial traits do exist. Please, next time you've got
> some time and are at a natural history museum, take a look at the bones
> in the flippers of a whale. Please note the similarities between these
> and the bones of your own hand. Note how much bone has been "recycled" in
> the whale.
Oh come on! The flipper of a whale has function - a bloody important
function. Of course evolution will favour the conservative use of
inherited bony and other structures rather than re-inventing the
wheel. This isn't analogous at all. You're arguing, remember, that the
notches in the distal radii in a'piths had NO FUNCTION - that they
were merely vestigial. A flipper of a whale is not a vestigial hand,
just flapping in the water with no function. It is very functional and
indicates the modified use of an inherited character.
> I'm sorry you're incredulous. It's going to be a huge handicap for you if
> you ever hope to be taken seriously. Again, like it or not, you're going
> to find that I'm a pretty good barometer of how others in physical
> anthropology will respond, save that I'm taking more time than most
> reviewers will, and as this isn't blind, I'm going to be more polite.
> You'll do better to stop telling people what they assume, telling people
> (erroneously as it were) that they are not basing their conclusions on
> fact, creating (rather comically at times) new scenarios to "explain"
> things that in fact fail to explain things.
I'm not convinced by the vestigial argument, sorry. I'm not just going
to believe it because teacher says so. Sorry about that too. I
appreciate your time and value your feedback greatly. I'm only
paraphrasing what you have told me before - I thought your idea of
a'piths was that they *were* terrestrial bipeds. Sorry if I
misunderstood that. Perhaps you will correct me. Or, then again,
perhaps this will be another episode of cat and mouse. It took you
about six months before you told me you were a physical
anthropologist, perhaps I'll have to wait another six months before
you let me know what you current idea is on a'piths so that I can make
some kind of assumption about your thinking again.
> >> We do, however, in these creatures, see clear signs of *bipedalism.*
> >
> >Yes but was it terrestrial bipedalism or wading bipedalism? You
> >*assume* terrestrial, I don't.
>
> LOOK, stop being a shit and telling me what I assume.
There's no need to be rude, Jason. And you think you're being more
polite than other phys anthropologists? Blimey. Do you treat your
students like that?
> The morphology fits
> with a terrestrial biped. It has the characteristics that would allow for
> terrestrial bipedalism as we know it. We have evidence (from tracks) that
> creatures engaged in terrestrial bipedalism away from water sources.
> Whether or not it was a wading biped is unknown.
Fine.
> >> >> So your totally depending on a rare trait (the notch) being something
> >> >> necessary for tiny amounts of time, selected for quickly, but the more
> >> >> universal traits seen in quadrupeds don't develop so quickly such that
> >> >> limited time quadrupedally results in nothing? Do you not see the problem
> >> >> with this?
> >> >
> >> >Not really.
> >>
> >> Obviously you don't. I wish you luck trying to publish. The specialists
> >> are going to eat you alive.
> >
> >Maybe the specialists would be able to tell me on what basis they
> >assumed the LCA was a knuckle-walker and how those traits evolved.
>
> Maybe you should read some of their papers.
I've read lots of their papers and will keep doing so.
I wouldn't say I was familar with the styloid process, no, but I'm
holding the ulna of my human skeleton and I can see what you mean. The
key word there was 'original'. I agree they can remain while not
serving their *original* function - but *function* they must have
otherwise they would have disappeared or have been transformed into
something unrecognisable from the monkey's.
I'm not suggesting that the distal notches on the radii of a'piths
were for knuckle-walking. I have you to thank for that. You convinced
me that they didn't have the full weight-bearing traits that you'd
expect if that were the case and so I abandonned the full k-w-er
model. BUT I cannot accept that they were functionLESS and just
vestigial from a k-w-ing ancestor, they must have had some function,
the question is: What function?
> Why did the notches remain vestigial for a million years? Because they
> didn't seem to get in the way sufficiently for that time and because when
> something's not under selection, it only disappears due to drift or until
> another selective pressure knocks it out. You seem to be assuming that
> the notch was a big deal, that, if not maintained by selection, it would
> have been a significant detriment. That's not supported by anything more
> than your conjecture, your nebulous notions of "bone recycling" aside.
Sorry, I'm just not convinced.
> >Ok. Notches that remain pretty much morphologically distinct for a
> >million years must have a function. Ask your osteo collegues what they
> >think about the vestigial idea. Please tell me what they say.
>
> NO. Notches that remain pretty much morphologically distinct for a
> million years DO NOT need to have a function. We're stuck here again.
> You're hung up on something that's not true.
> I have asked my osteo colleagues about it. They've got no problems with it
> being a vestigial trait. In fact one has published commentary saying
> exactly as much. You poo-pooed that paper for reasons that seem not
> entirely clear other than that you said you didn't buy it.
Blimey, I must be going senile. I have no memory of that. I don't
suppose, pretty-please, you could tell me the paper again could you?
> >I'm confident in what I know and don't know too. Plus, I'm happy to
> >admit my ignorance when it exists. I have no reputation to protect and
> >no peers looking over my shoulder to worry about. If I'm wrong to be
> >sceptical about this vestigial idea then show me how.
>
> You're going to have to take that leap yourself.
If you tell me the paper or some info so I can find it, then I promise
to read (re-read?) it.
> >> >Of course not. Why does the lack of fossil evidence stretch the
> >> >credibility of the vestigial argument? Because you have no data
> >> >whatsoever on which to base the assumption that any such type of
> >> >locomotion happenend before.
> >>
> >> I have no *fossil* data. On the other hand, there's considerable
> >> comparative data suggesting that the trait wasn't functional.
> >
> >That's just based on your interpretation, your *assumption* that they
> >were terrestrial bipeds. They may not have been.
>
> OK, I'm tired of being polite you ignorant shit. Stop telling me what my
> assumptions are as if I'm making things up. Stop acting just like the
> rest of the pseudoscience fruitcakes.
So, that is your idea of being polite? *Not* calling me an ignorant
shit? Mmm, your idea of manners is a bit different from mine.
Ok, ok, I'll stop using the words 'you assume' - from now on I'll try
to remember that you assume nothing, that you are the perfect
scientist who has no biases, no pre-conceptions and is totally open to
anything as long as data backs it up.
... must ... not ... be... a fruitcake.
> >Timeline
> >-7mya---6mya---5mya---4mya---3mya---2mya---1mya---Present
> >
> >No evidence of k-w
> > Some evidence of k-w
>
>
> You misspelled "evidence of a trait, but no evidence of knucklewalking"
Corrected. I should have put somthing like 'evidence of a trait which
may be associated with analogous traits in extant apes associated with
knuckle-walking' but you know, time 'n all that.
> > Apes k-w
> >
> >... and yet you want to posit...
> >
> >Timeline
> >-7mya---6mya---5mya---4mya---3mya---2mya---1mya---Present
> >
> >k-w-er Apes k-w
> > vestigial k-w
> >
>
> Yes, that's what I want to say. It's the interpretation that fits with
> the phylogenetic and comparative evidence and doesn't have contradictions
> in the fossil evidence. You're proposing a scenario that contradicts
> phylogenetic evidence and comparative evidence.
But how, when did the k-w-ing come in?
> >Ok - give me a clue about this evidence. Where might I find it?
>
> Sigh. Several months ago I provided you with references of studies on
> knucklewalkers. Did you ever bother to read any of those?
Sorry. We moved to Australia 5 months ago and the months around that
were exceptionally busy and stresful. I must forgot to read up on
those refs, sorry. I'll search back on the ng's archives to see if I
can find them again.
> Please, and I
> realize I'm sounding somewhat like Marc here, but why should I bother
> looking things up again when I've seen ZERO evidence from you that you're
> willing to consider things?
I don't expect you to look them all up again but if you could... :-)
I'm willing to consider things. You've already changed my mind on
a'pith k-w-ing to some degree - that's not ZERO.
> Why, when what inevitably happens is you
> accuse me of making assumptions as if I'm making things up, should I try
> to force your fingers out of your ears? Algis, you don't act like someone
> who is at all interested in trying to falsify your ideas.
With respect, neither do you.
> From my
> vantage, you seem like you're intent on insulating your ego from
> substantive attacks on your pet hypotheses. I'm tired of wasting my time
> if you're going to continue to act like a shit in return.
I'm sorry about the refs. I'll read them. I appreciate greatly your
time and feedback. I'm not bothered or motivated by ego I assure you.
My motivation in this matter is, as it always has been, to question
why aquatic explanations are so poorly received and so little academic
attention has been given toward them. There is no excuse for being
rude, though. It only makes me more determined to prove you wrong.
> You apparently have a master's degree. You should know how to use a
> biological reference search engine. Finding papers discussing the
> evolution of knucklewalking isn't hard. I'm tired of holding your hand.
Ok. Fair point. It's just a time saver if you know the papers you mean
and you want me to read that you supply a ref. If you have something
to hand it'd help me that's all.
> >Placing a'piths is difficult. I don't think anyone is sure if they're
> >ancestral to Pan/Gorilla but that seems to me to be just as likely the
> >idea that they're ancestral to Homo. More likely neither.
>
> No, less likely, for a number of reasons. Apiths shared *derived* cranial
> and dental characteristics with Homo where apes retain the ancestral
> catarrhine form. You have to have a reversal of several characteristics
> (including, but not limited to: the reduction and elimination of a honing
> complex, the addition of a second p3 cusp, absolute canine reduction, more
> forward placement of the foramen magnum, shortened cranial base, increased
> cranial flexion) if you accept apiths as ancestral to Gorilla or Pan.
> Note that these are characteristics that are *independent* of the
> postcrania, which likewise shows derived traits relative to bipedalism
> where apes retain a primitive form.
> That apiths weren't directly ancestral to humans is quite likely. That
> they're in a clade with humans with the African apes as an outgroup, that
> we share a more recent common ancestor with apiths than with apes is in
> fact far more parsimonious than apiths being ancestral to apes or a
> trichotomy with the three.
> You have a master's in physical anthropology, no? Quite frankly, I'm
> shocked that you could have received this degree without being aware of
> this.
Yes, I was aware of this being one interpretation. My masters was in
Human Evolution and Behaviour. It was a one year, taught course in
which Paleoanthropology was one of five units. I certainly claim no
expertise in the subject. I remember finding the paleo labs rather
whishy-washy. We'd have to examine fossils and identify if they had
such-and-such a character. More often than not it was totally
ambiguous whether they had it or not. I remember the lectures about
'muddles-in-the-middle', about lumpers versus splitters about the
debates and disagreements on the incredibly sparse fossil record,
whether this tiny tooth or bone could be placed in this hypodigm or
that hypodigm or whether it should be given a new phylum of its own.
The take-home message for me was that it wasn't a very hard science
and that it was best to be very sceptical about any conclusions anyone
had come to based upon fossil evidence, especially when it came to
conclusions on phylogeny. I remember one lecture that Mark Collard
gave where he candidly admitted that bony characters may well be
poorer than soft characters in assessing phylogeny.
His (joint) paper in PNAS v97(20) 11130-11132 bore that out.
So, sorry if I'm a bit hypersceptical of your phylogenetic models,
Jason. I guess I'm just not that impressed with what I learned. I
certainly didn't learn anything that made me doubt that the earliest
bipeds could have been waders.
> >> >So - either it's a fully quadrupedal fully-weight-baring
> >> >knuckle-walker or it's not. Black or White. On or Off. How on earth do
> >> >you teach anything to do with evolution? Are you a creationist in
> >> >disguise?
> >>
> >> Hey, Algis, the creationist slander will only make you look bad. If
> >> you're just trying to be pissy, fuck off and die. Come back once you've
> >> actually learned something. If you really think you're winning points,
> >> I'm confident in my ability to teach evolutionary biology because I've got
> >> a good track record doing it. You can say the same?
> >
> >Gosh. Please don't be so sensitive. It was kind-of a joke. I'm sorry
> >if I offended you. I certainly didn't mean it as *slander*. Get a
> >life. Get a sense of humour, please.
>
> It doesn't seem like humor. It seems like you'd run out of anything
> substantive to say and decided to pull the creationist line. The attack
> on my teaching was just plain rude. I don't know what you do for a
> living, but I don't think I've ever questioned what you do. [note if
> you're still trying to figure it out: teaching physical anthropology is
> what pays my bills.]
I didn't mean to be rude. And, compared to calling me a 'twit',
suggesting I should 'fuck off and die' and other insults, I'd say it
was a far, far milder form of criticism.
> >> Again, for the umteenth time: there are ZERO characteristics of apiths
> >> that are part of the common suite found in ALL quadrupeds related to
> >> quadrupedalism. While it may be that there are shades between in an
> >> idealized case, right here, with this real data there is not evidence that
> >> we're not at a zero-level quadrupedalism.
> >
> >But I'm not arguing they were quadrupeds - for the (umpteen + 1)th
> >time. I (think) you put in an extra 'not' in there. I think that is
> >exactly what the evidence shows - at leats it is a reasonable
> >interpretation of the data.
>
> The evidence indicates apiths to be zero level quadrupeds. I stand by
> this.
> >Not necessarily but very likely. Chimps are better at moving through
> >trees than we are - no-one would doubt that that was adaptive - or,
> >more precisely that our loss of ability there is due to a loss of
> >those adaptations. So, why when it comes to just another way of moving
> >- through water - do you need to invoke mysterious forces which have
> >nothing to do with evolution?
>
> I invoke that you're reading much into it. I invoke that you want to use
> water to explain many things that it explains poorly or explains only by
> contradicting things that are better explained in other ways. There's no
> evidence that a common ancestor of humans was ever committed to needing to
> swim such that it resulted in any of the characteristics you say would
> have resulted from needing to swim and further those characteristics that
> you say are clearly the result of swimming pressure don't appear to me to
> be consistent with such a pressure.
I've never claimed the LCA of Pan/Homo needed to swim - just that it
was a wading ape.
I need to get on with some work. I'm spending far to long discussing
this with you. We're getting nowhere fast.
I'll try to find the papers about evolution of knuckle-walking and see
what affect that has.
Algis Kuliukas
Marc Verhaegen
> > > In the case of Marc and Algis their insistence that Richmond and
Strait argue for a'piths being knuckle-walkers is a case in point. They
consistently do this *without* noting that R & S *do not* make that
argument. Using somebody's data for your own purposes is perfectly
acceptable but you *do not* cite them as supporting your argument. This is
dishonest and is exactly the sort of shenanigan that will deny the AAT any
hearing.
....
Wagler, for once, use your brain.
- R&S said apiths (some at least) had KWing features. I have no reason to
doubt this.
- R&S assume that this is a relic. That is nonsense for everyone who uses
the data & his brains.
Too diffucult for you?
No time to read your further nonsense.
I fully agree with Algis of course.
Richard Wagler
Marc Verhaegen wrote:
> "Richard Wagler" <taxi...@shaw.ca> wrote in message
> news:3EC10C1D...@shaw.ca...
>
> > > > In the case of Marc and Algis their insistence that Richmond and
> Strait argue for a'piths being knuckle-walkers is a case in point. They
> consistently do this *without* noting that R & S *do not* make that
> argument. Using somebody's data for your own purposes is perfectly
> acceptable but you *do not* cite them as supporting your argument. This is
> dishonest and is exactly the sort of shenanigan that will deny the AAT any
> hearing.
> ....
>
> Wagler, for once, use your brain.
> - R&S said apiths (some at least) had KWing features. I have no reason to
> doubt this.
Except those features that would actually allow a'piths to
knucklewalk.
>
> - R&S assume that this is a relic. That is nonsense for everyone who uses
> the data & his brains.
Why? What makes their argument nonsense
>
> Too diffucult for you?
Yes. I just can't figure out a kw'er does it
*without* putting a load on its forearms.
Perhaps you would care to elucidate the
advantages of knuckle-dragging as a form
of locomotion. Too difficult for you?
>
>
> No time to read your further nonsense.
Cut and run, eh? Well that's your modus
operandi after all...
>
> I fully agree with Algis of course.
Poor devil.....
Rick Wagler
Marc Verhaegen
> > > > > In the case of Marc and Algis their insistence that Richmond and
Strait argue for a'piths being knuckle-walkers is a case in point. They
consistently do this *without* noting that R & S *do not* make that
argument. Using somebody's data for your own purposes is perfectly
acceptable but you *do not* cite them as supporting your argument. This is
dishonest and is exactly the sort of shenanigan that will deny the AAT any
hearing.
> > Wagler, for once, use your brain. R&S said apiths (some at least) had
KWing features. I have no reason to doubt this.
> Except those features that would actually allow a'piths to knucklewalk.
??
> > R&S assume that this is a relic. That is nonsense for everyone who uses
the data & his brains.
> Why? What makes their argument nonsense
1994. Australopithecines: ancestors of the African apes? Human Evolution 9,
121-139
http://allserv.rug.ac.be/~mvaneech/Fil/Verhaegen_Human_Evolution.html
2002. M. Verhaegen, P.-F. Puech & S. Munro. Aquarboreal ancestors? Trends in
Ecology & Evolution 17, 212-217
http://reviews.bmn.com/journals/atoz/latest?pii=S0169534702024904&node=TOC%4
0%40TREE%40017%4005%40017_05
Marc Verhaegen
"Algis Kuliukas" <al...@RiverApes.com> wrote in message
news:77a70442.03051...@posting.google.com...
> "I know Richmond & Strait's paper was careful not to propose anything so
controversial as the idea that A'piths were knuckle-walkers. I never, for
one moment, pretended that they did. In fact I also noted the Aiello &
Collard article in the same edition of Nature which made the same point that
you do. So, who is being dishonest here?"
Still no answer.
> > Marc consistently cites reams of scientific references in support of his
scenario, and never once mentions that they are referenced based on his
interpretation of the author's paper. This lays him open to a charge of
intellectual dishonesty, especially when he is using the refs with a lay
audience, such as SAP.
> Better to cite scientific references that offer data (or at least
quotations) that support his scenario than not to do so. If he did that,
you'd just criticse him for something else. Of course his citations are
selective but what do you expect there? Considering the body of opinion is
stacked against the AAH, I think Marc's efforts to quote from recognised
papers is rather admirable. It seems to me that Marc just can't with with
you guys.
Still no answer.
> > Literature searches are of course a mainstay of Marc's scenario, as he
apparently undertakes no original research of his own. Nothing wrong with
that per se, but very few of his sources, as you would know, would agree
with his interpretations of their data as it relates to hominid evolution...
> So what? Algis Kuliukas
Still no answer.
Marc
Ross Macfarlane
>
> Still no answer.
>
> Still no answer.
>
> Still no answer.
>
Two can play at that game...
Can you present any scientific evidence that presence or absence of
fur has any bearing on aquatic vs. on-aquatic origin?
Can you present any credible scientific evidence that suids (members
of the pig family) were ever "aquatic"?
Rank the following mammals of similar body weight in terms of surface
area:
a. Harbour seals
b. Warhogs
c. Humans.
What, if anything, can be concluded from the relative surface areas
of the 3 mammals of similar body weight in question 3. above?
Specifically, if the finding is that humans have the largest surface
area of the 3 mammals listed, does this make it more or less likely
that they had an aquatic or "aquarboreal" past, and why?
How do you reconcile your claim that "aquarboreal"
hominid ancestors must have had a lower relative surface area to body
size (and more subcutaneous fat), with the observation from the fossil
record that all known skeletons of hominids have body shapes
transitional between humans and apes, and therefore similar relative
surface areas to extant hominids & apes? In other words, since your
claim is directly contradicted by the fossil evidence, can you present
evidence in support of your position, or will you withdraw this claim?
Can you present any scientific evidence to back up your explicit claim
that "Humans probably have rel.lower body surface area than chimps,
eg, more rounded forms"?
It's more than just knuckle-walking - the changes required to produce
a biped are enormous. Both gorilla & pan re-evolved opposable big toes
from australopithecines who had lost them? Both evolved
rearward-facing foramen magnums?
And you call this scenario more parsimonious?
> Whatever. How do pandas or chalictheres contracdict our scenario??
The evidence about chalicotheres & ground sloths contradicts 2 strands
in your scenario: comparative evidence, & evidence that knuckle
walking pan & gorilla evolved from waders.
I gave you comparative evidence of terrestrial knuckle-walkers, who
evolved from probable terrestrial and arboreal ancestors, as models
for Gorilla & Pan. Now you give me 2 knuckle-walkers who evolved from
waders, as models for Gorilla & Pan. If you cannot, why should we
accept your arguments that they evolved from waders?
I take it that, using the ground-sloth / chalicothere models, you now
concede the point that knuckle-walking could have evolved in
terrestrial great apes, without resort to a semi-aquatic explanation?
> Balls. Inform a bit. Facts: early apiths (eg, Lucy) seem to have had
> rel.shorter arms than humans (estimations: humerus Lucy 24, bonobo 29, human
> pygmy 26 cm). Later apiths, eg, boisei, habilis (OH-62), evolved longer
> arms.
What is the arm length for the Turkana boy, & for a Masai?
You do realise that the valid comparison here is to measure the ratio
of length of the humerus (upper arm) and length of the femur (upper
leg), not absolute length of the humerus bone?
Are you aware that using this measure, Pan has a humerus/femur ration
of ~115%, australopithecines ~95%, Turkana boy and modern humans <90%?
Do you agree that although the Turkana boy died in water, this does
not mean he lived in water?
> Ever thought why Turkana Boy was so dissimilar
> from modern humans, eg, why he had vertebral height much lower than any
> modern population?? Clear?
>
Have thought about that, yes. Results from him having more "primitive"
condition - i.e. hasn't evolved the longer vertebral height seen in
modern humans. In fact his vertebral configuration is transitional
between australopiths & modern humans - as one would expect if his
species (let's call it early Homo erectus) had evolved from an
australopithecine - or from an a'pith ancestor - and H. sapiens had
evolved from early H. erectus. Comment?
Surely you don't wish to claim that OH-62 / Lucy are more human-like
than the Turkana boy?
Do you agree that early Homo (erectus / ergaster - e.g. the Turkana
boy) had a lower humerus to femur length ratio than australopithecus
(afarensis
*or* africanus)?
Your scenario requires unevolving bipedal hominid feet, hips, skulls
etc. in 3 distinct lineages (Pan & Gorilla), and possibly Pongo as
well. How do you make this parsimonious?
> Forgot that gorilla rel.arm length is more like human than like orang
> rel.arm length??
Factually erroneous claim, made without supporting data. Gorilla
humerus-femur ration is >110%; so is orang utan. Human is <90%.
Agreed?
Forget that gorilla hips, feet, skulls, vertebra, hands are more
orang-like than human-like??
A change in long bone length could be caused by a single point
mutation. How many does it take to move a foramen magnum from rearward
to downward-facing, & back again?
> > What boisei arm bone fossils are you referring to?
>
> You can find it here
> http://allserv.rug.ac.be/~mvaneech/Fil/Verhaegen_Human_Evolution.html Again:
> inform before writing nonsense. You're so terribly biased.
Where here? Please provide an exact scientific reference - author,
paper, page number.
> *Wrong*!! Lucy probably had much shorter arms than OH-62.
Cite a ref. Otherwise I'll continue to rely on the refs. I've read,
which tell me that given the poor state of preservation of OH-62, &
the fact that it's only a single fossil, there is no statistical
difference between Lucy & OH-62.
Note: if there's no statistical difference, then in a scientifically
pedantic sense, Lucy's arms were "probably" not shorter than OH-62's.
> > > Not following? Point: spider monkeys are not bipedal.
> > Not following? Point: spider monkeys are not apes.
>
> That's no point.
The point is clear to all but you Marc. Spider monkeys are not apes.
Therefore they exhibit different adaptations to brachiation and
bipedality / quadrupedality to gibbons & other apes. Your comparative
evidentiary methodology, taken to extremes, could imply that
brachiation could only evolve in a primate which had a long prehensile
tail.
My point is that the evolutionary history of an ape constrains it to
develop in different ways from spider monkey, & therefore the
comparison of bipedality in hylobatids to quadrupedality in spider
monkeys is invalid. OK?
*How*, *when*, and *why* would a obligate bipedal aquarboreal wader
knuckle-walk? ("When" meaning when on any given day, not when in
evolutionary
history.)
Can you tear down the cladistic straw man I presented, as follows? -
I started by overlooking the genetic evidence to the contrary, &
assumed that Pan is closer to Gorilla than Homo. That led to the
following cladogram for extant apes & modern humans:
/---------------------------------- Old World Monkeys
/
(1)- /--------------------------- Hylobatids (gibbons)
\ /
\-(2)- /-------------------- Pongo (orang utan)
\ /
\-(3)- /---- Gorilla (gorilla)
\ /
\ /-(5)- /- Pan troglodytes
\ / \ / (chimpanzee)
\-(4)- \-
\ \ Pan paniscus
\ \- (bonobo)
\
\--------- Homo (humans)
Algis & Marc hypothesise that the Gorilla / Pan / Homo last common
ancestor (4) was a wading biped. But (4) shares a LCA with Pongo at
(3). So either the wading biped evolved after this split, or (3) was
more similar to the wading biped. Either way, any similarities between
orang utans & African great apes would be due to convergent evolution.
So, to test if it is more parsimonious to assume that the LCA at (4)
was more like a bipedal australopith, or a knuckle-walking great ape,
I came up with the following straw man of features:
Pongo Gorilla Pan Homo A'pith Feature
===============================================
No Yes Yes No No Knuckle-walking
Yes Yes Yes No No Grasping foot
Yes Yes Yes No No Opposable toe
No No No Yes Yes Obligate biped
No No No Yes Yes "Bowl-shaped" pelvis
No No No Yes Unknown Hairless
No No No Yes Yes Reduced canines
Yes No No Yes Yes Parabolic maxilla
Yes Yes Yes No No Arms longer than legs
No Yes No No Robusts Sagittal crest
The list is selective, based as it is on obvious gross morphological
features that a layman like me can identify. But its message is clear:
the idea that a bipedal LCA separately evolved into orang-like & chimp
/ gorilla-like descendants is vastly less parsimonious than the
alternative hypothesis, that an australopithecine biped (whether
terrestrial or a wader) evolved from a chimp-like ancestor.
However, the genetic evidence is that Pan is more closely related to
Homo than either is to Gorilla. Revising the cladogram to coincide
with the genetic evidence, I get this:
/---------------------------------- Old World Monkeys
/
(1)- /--------------------------- Hylobatids (gibbons)
\ /
\-(2)- /-------------------- Pongo (orang utan)
\ /
\-(3)- /-(8)----- Gorilla (gorilla)
\ /
\ / /- Pan troglodytes
\ / / (chimpanzee)
\-(6)- /-
\ / \ Pan paniscus
\-(7)- \- (bonobo)
\
\---- Homo (humans)
This makes the hypothesis of the wading biped even less parsimonious
than the first cladogram, because it requires an australopithecine
biped, at (6), to evolve into gracile (7) & robust (8) forms, which
separately evolve into knuckle-walking apes. This means that the suite
of ape-like features the 3 great ape genera share evolve independently
3 times.
So: that's my straw man. If Algis or Marc are going to continue to
promote the hypothesis of a wading bipedal ancestor of knuckle-walking
great apes, they will have to tear down my straw man, & produce an
alternative to my list of comparative features, & show how & why their
view is more parsimonious. They will also need to show why the genetic
evidence, that chimps & bonobos are closer to humans than to gorillas,
is wrong...
Ross Macfarlane
Algis Kuliukas
> Algis Kuliukas wrote:
> > > In the case of Marc and Algis their insistence that
> > > Richmond and Strait argue for a'piths being knuckle-walkers
> > > is a case in point. They consistently do this *without*
> > > noting that R & S *do not* make that argument. Using
> > > somebody's data for your own purposes is perfectly
> > > acceptable but you *do not* cite them as supporting your
> > > argument. This is dishonest and is exactly the sort of
> > > shenanigan that will deny the AAT any hearing.
> >
> > What?
> >
> > So if somebody does research and produce a body of data and decides to
> > publish a paper interpretting that data one way, others cannot use the
> > same data but interpret it in another way, later? Nonesense.
>
> I suggested this???
You pretty much were suggesting that I couldn't use Richmond &
Strait's data which showed that a. afarensis had k-w traits in favour
of an argument that they actually performed some kind of
knuckle-walking simply because they themselves didn't come to that
conclusion themselves.
> > That is more or less exactly what Rodman & McHenry (1980) did with the
> > Taylor and Rowtree (1973) data. They originally interpreted to
> > conclude that energetic efficiency could not be used as an argument in
> > favour of bipedalism, R & McH re-interpreted it to mean that it
> > couldn't be used againat the energy efficiency argument. So, were they
> > dishonest? Somehow, I think that you'll come up with a formula of
> > words that lets them off the hook but attempts to keep me firmly on it
> > but then, perhaps - you never know - maybe you could show some
> > objectivity and concede that you overstretched your argument.
>
> Nonsense. Did R & M ever suggest that T & R supported
> their position. Please get clear in your head what proper
> citation is all about. You are going to have to understand this.
No - and neither did I. I know Richmond & Strait didn't interpret
their findings in this way. As I said, but you conveniently ignored, I
tied this suggestion to the fact that Aiello & Collard said the same
thing themselves in the same journal. This is hardly trying to pretend
that Richmond & Strait were arguing in favour of my position, is it?
You need to calm down, Richard, and stop getting so over-anxious about
this stuff.
> > There are countless examples of this kind of thing in the literature.
> >
> > I know Richmond & Strait's paper was careful not to propose anything
> > so controversial as the idea that A'piths were knuckle-walkers. I
> > never, for one moment, pretended that they did. In fact I also noted
> > the Aeillo & Collard article in the same edition of Nature which made
> > the same point that you do. So, who is being dishonest here?
>
> You are. You are claiming, on no evidence of any sort, that
> R & S are 'careful' not to propose a controversial interpretation
> directly implying that the explanation for these traits that they
> present are not their true opinions. This is ridiculous. You have
> utterly no reason to accuse R & S of duplicity.
You're trying to read too much into what I wrote. I'm not implying
that they secretly believed that a'piths really were knuckle-walkers.
Nothing of the sort. It's you who's being paranoid here, not me. I
don't know what they believe. I suspect it is along the lines of what
they actually wrote. We have to take what they published on face value
- of course.
But, let's face it - it *is* a controversial topic. I mean look at how
much angst it is causing in you in this thread. And, I am sure that
they were well aware of that controvery when they published and wanted
to make it perfectly clear to everyone that they weren't actually
suggesting anything of the sort. That is all I meant. I am not an
aqua-conspiricy theorist.
> > But ;let's get to the issue, seeing you raised it. Why didn't they
> > suggest that knuckle-walking traits indicated knuckle-walking?
>
> So you refuse to understand that a suite of features is
> indicative of kw. Ostriches have wings. Do ostriches
> fly? Why not and how, from an anatomical point of
> view, can you tell? Or do you think the anatomy of an
> ostrich is identical re flight compared to an eagle? Maybe
> you do....
I suggest that ostrich wings have *some* function. Clearly it is not
for flight and I don't know enough about ostriches to guess what it
might be but - not *nothing.* The vestigial argument for the notches
in a'piths argues that they had *no function* I think it is far more
likely that they had some function. I'm not suggesting that it was
full weight-bearing knuckle-walking as we see in Pan/Gorilla today - I
thank Jason for helping me to see that - but that it might have been
an early manifestation of its evolution, perhaps to help support the
body whilst feeding.
> > It
> > would be a parsimonious view after all. Perhaps they concluded that
> > the peer pressure would be too great to make such a suggestion perhaps
> > it was because the other traits in a. afarensis indicated a bipedal
> > posture and the two couldn't be reconcilled.
>
> Perhaps they believe what they wrote. Absent any evidence
> to the contrary simple courtesy and professional competence
> make this the null position. Your ascription of darker motives
> to R & S is outrageous
I'm sure you're right and they do believe exactly what they wrote.
'Darker motives'! Come off it. You're just trying to stir it up. They
published a very interesting paper and chose to intrepet their data in
one way. I read it and saw an alternative interpretation. I just find
it rather amusing that any hint of of any evidence that might be
construed as support of an alternative view is attacked with such
venom.
> > As Aiello & Collard
> > pointed out - how could this animal be a terrestrial biped *and* also
> > be a knuckle-walker? Of course, neither Richmond or Strai or Aiello &
> > Collard considered the possibility that A. afaransis might have waded,
> > thus solving the riddle.
>
> Yeah, right.....
Knee-jerk ridicule - the standard response, I suppose. But considering
that the only way of getting apes to move bipedally for indefinite
periods of time is to place them in waist deep water, then wading as a
precursor to hominid bipedalism deserves more serious consideration
that that.
And, considering that apes do use their knuckles for support whilst
leaning on the banks whilst getting food or as they prepare to get out
of the water, then some manifestation of k-w traits for support is
consistent with what we see in a'piths if they did indeed wade.
> > The fact is that the data they did publish does show analogous traits
> > in A'piths to those in Pan/Gorilla for knuckle-walking. The idea that
> > this was a vestigial trait for one-million years from an ancestral
> > knuckle-walker is the only notion that can possible explain it other
> > than, of course, the crazy idea that they actually knuckle-walked.
>
> So you don't understand what vestigial traits are either...
Sorry, Richard. What do you mean by that? Why have you got to slip
into abuse at every opportunity. I've always been courteous and
respectful to you - why do you find it so hard to return the
complement?
> > As there is a great deal of evidence to show that bones are very
> > plastic in one life time (witness tennis players cortical thickening
> > for one simple example) it seems farcically inconceivable to me that
> > such exposed bony structures as notches on the distal radii would
> > remain, without any function, for one million years. What do you
> > think?
>
> I think things atrophy rather quickly then hang around
> for a long time. You can't take bone platicity to absurd
> lengths. Why do you think an ostrich has wings?
But they didn't atropy - they stayed - apparently without function -
for a million years.
It's interesting. I was reading an old paper on this by Russel Tuttle
the other day on the origin of knuckle-walking. He was postulating
whether A'piths might have been knuckle-walkers and thought it
unlikely.
He wrote (Tuttle 1969:p959) "Unfortunately there are no distal radii
or metacarpal bones. From these bones the occurance or nonoccurance of
knuckle-walking might be discerned more readily." This was, of course,
before the Afar a'pith finds.
Now before you jump on me for implying that Russel Tuttle would have
concluded that a'piths knuckle-walked if such fossils had been found -
let me say I am not suggesting that - heaven forbid!! Just that the
presence or absence of notches on the distal radius seemed to carry
some weight in this discussion to the one of the leading experts on
knuckle-walking.
Tuttle, Russel H (1969). Knuckle-walking and the problem of human
origins. Science Vol:166 (3908) Pages:953-961
> > Why don't you focus on the issues and data instead of pouring slur on
> > those who happen to hold a different view to yourself?
>
> The only slur being tossed out is your's against R & S.
Rubbish. I have nothing but respect for them as I have for every
paleoanthropologist.
> Your reply amply demonstrates the truth of my original
> statement. There are some rather basic things regarding
> honour, respect, and common human decency with regard
> to others in the field that you are going to have to learn
> if you plan to pursue this academically. Your position
> in this post is completely unsupportable and dishonourable.
Get a grip, man. You're taking this thing to a ridiculous level. I
merely choose to interpret their findings differently than they do
that's all.
Algis Kuliukas
Algis Kuliukas
> Two can play at that game...
Not sure if this is for me to answer but I'll try to answer questions
which I think are at least partly aimed at my view. I'm going to leave
others for Marc.
> Can you present any scientific evidence that presence or absence of
> fur has any bearing on aquatic vs. on-aquatic origin?
Not that one again.
Looking at mammalia - at least eleven independent evolutions of
hairlessness.
4 - for aquatic reasons (cetaceans, sirenians, phoceians, hippos), 3
for 'large size/cooling' (eg elephants/rhino/pigs?), 2 for scaling up
(armadillos, pandolins), 1 for subterraenean burrowing (mole rat) -
and 1 unkown - Homo.
Aquatic reasons are the number one reason. Ok, perhaps not a majority
but a significant one. So, if you're open minded, worthy of
consideration.
> Can you present any credible scientific evidence that suids (members
> of the pig family) were ever "aquatic"?
No, not at the moment. Can you present any that they were not? It
seems quite a plausible position to me. One worthy of keeping an open
mind on, I think.
> Rank the following mammals of similar body weight in terms of surface
> area:
>
> a. Harbour seals
>
> b. Warhogs
>
> c. Humans.
>
> What, if anything, can be concluded from the relative surface areas
> of the 3 mammals of similar body weight in question 3. above?
a, b, c - so humans with the greatest surface area. What can be
concluded? Mmm... let me think... I know, that humans must be the
least aquatic? Am I right? Remember though, Ross, we're not arguing
that humans were ever aquatic in that sense. Just that they were
exposed to pressure to move through water (wade, swim, dive) more than
our ape cosuins.
> Specifically, if the finding is that humans have the largest surface
> area of the 3 mammals listed, does this make it more or less likely
> that they had an aquatic or "aquarboreal" past, and why?
Sorry, I've gotten ahead of myself. According to the usual
interpretation of what aquatic adaptations are then of course it makes
it *less likely* they had an aquatic past. It says absolutely nothing
about whether or not they had an aquarboreal past, however, because
swimming isn't really part of that model and living in water certainly
is not.
> How do you reconcile your claim that "aquarboreal"
> hominid ancestors must have had a lower relative surface area to body
> size (and more subcutaneous fat), with the observation from the fossil
> record that all known skeletons of hominids have body shapes
> transitional between humans and apes, and therefore similar relative
> surface areas to extant hominids & apes? In other words, since your
> claim is directly contradicted by the fossil evidence, can you present
> evidence in support of your position, or will you withdraw this claim?
I never did make that claim. (Must be talking to Marc here) As As
water-living is not part of any form of AAH I could associate myself
with I think it irrelevant to compare surface area altogether.
> Can you present any scientific evidence to back up your explicit claim
> that "Humans probably have rel.lower body surface area than chimps,
> eg, more rounded forms"?
Ditto above.
> It's more than just knuckle-walking - the changes required to produce
> a biped are enormous. Both gorilla & pan re-evolved opposable big toes
> from australopithecines who had lost them? Both evolved
> rearward-facing foramen magnums?
>
> And you call this scenario more parsimonious?
And yet it is still possible. There is no evidence whatsoever for a
knuckle-walker that predates 3.5 my and yet you (presumably) have no
problem in assuming that a'piths were ex-knuckle walkers on the way to
human-like bipedalism. There is quite a bit of evidence for a bipedal
LCA (Orrorin and Sahelanthropus dated at 6 and 7 mya, respectively and
a body of evidence which might indicate a LCA dated at about 5mya.)
The earliest 'aquarboreal' apes need not have been as specialised for
bipedalism as you seem to assume.
I am not arguing that a'piths were ancestral to Pan/Homo but I have an
open mind to the possibility. The opposable toe and other reversals
suggest that this is a less parsimonious model, I agree - but that
does not prove it.
> > Whatever. How do pandas or chalictheres contracdict our scenario??
>
> The evidence about chalicotheres & ground sloths contradicts 2 strands
> in your scenario: comparative evidence, & evidence that knuckle
> walking pan & gorilla evolved from waders.
> I gave you comparative evidence of terrestrial knuckle-walkers, who
> evolved from probable terrestrial and arboreal ancestors, as models
> for Gorilla & Pan. Now you give me 2 knuckle-walkers who evolved from
> waders, as models for Gorilla & Pan.
Absence of evidence is not...
> If you cannot, why should we
> accept your arguments that they evolved from waders?
You should have an open mind to it because:
a) There is no evidence of knuckle-walking preceding a'piths
b) There is evidence of bipeds preceding a'piths and k-w-ers
c) Exatnt apes do wade and do use their knuckles for support on the
water margins and when getting out of the water.
> I take it that, using the ground-sloth / chalicothere models, you now
> concede the point that knuckle-walking could have evolved in
> terrestrial great apes, without resort to a semi-aquatic explanation?
Of course.
[snipped conversation about rel limb lengths of H. erectus]
> Do you agree that although the Turkana boy died in water, this does
> not mean he lived in water?
Of course.
> Do you agree that early Homo (erectus / ergaster - e.g. the Turkana
> boy) had a lower humerus to femur length ratio than australopithecus
> (afarensis
> *or* africanus)?
>
> Your scenario requires unevolving bipedal hominid feet, hips, skulls
> etc. in 3 distinct lineages (Pan & Gorilla), and possibly Pongo as
> well. How do you make this parsimonious?
The earliest 'aquarboreal' apes need not have been as specialised for
bipedalism as you seem to assume.
> A change in long bone length could be caused by a single point
> mutation. How many does it take to move a foramen magnum from rearward
> to downward-facing, & back again?
Dunno but how would you explain Orrorin/Sehalanthopus *if* the
molecular data evidence suggesting a LCA of Pan/Homo at around 5mya
was actually correct?
[...]
> My point is that the evolutionary history of an ape constrains it to
> develop in different ways from spider monkey, & therefore the
> comparison of bipedality in hylobatids to quadrupedality in spider
> monkeys is invalid. OK?
Ok. I think that comparative evidence can be used to favour whatever
position you want. The comparisons that matter are between humans and
Pan/Gorilla. Other than that generalisations from comparative data can
be used only as a general guide.
> *How*, *when*, and *why* would a obligate bipedal aquarboreal wader
> knuckle-walk? ("When" meaning when on any given day, not when in
> evolutionary history.)
When feeding from sedges on river banks, when getting out of the
water, when supporting itself before reaching up to climb a tree. Lots
of places I'd think.
> Can you tear down the cladistic straw man I presented, as follows? -
>
> I started by overlooking the genetic evidence to the contrary, &
> assumed that Pan is closer to Gorilla than Homo. That led to the
> following cladogram for extant apes & modern humans:
>
> /---------------------------------- Old World Monkeys
> /
> (1)- /--------------------------- Hylobatids (gibbons)
> \ /
> \-(2)- /-------------------- Pongo (orang utan)
> \ /
> \-(3)- /---- Gorilla (gorilla)
> \ /
> \ /-(5)- /- Pan troglodytes
> \ / \ / (chimpanzee)
> \-(4)- \-
> \ \ Pan paniscus
> \ \- (bonobo)
> \
> \--------- Homo (humans)
>
> Algis & Marc hypothesise that the Gorilla / Pan / Homo last common
> ancestor (4) was a wading biped. But (4) shares a LCA with Pongo at
> (3). So either the wading biped evolved after this split, or (3) was
> more similar to the wading biped. Either way, any similarities between
> orang utans & African great apes would be due to convergent evolution.
A good sumary of the problem, I'd say.
> So, to test if it is more parsimonious to assume that the LCA at (4)
> was more like a bipedal australopith, or a knuckle-walking great ape,
> I came up with the following straw man of features:
>
> Pongo Gorilla Pan Homo A'pith Feature
> ===============================================
> No Yes Yes No No Knuckle-walking
> Yes Yes Yes No No Grasping foot
> Yes Yes Yes No No Opposable toe
> No No No Yes Yes Obligate biped
> No No No Yes Yes "Bowl-shaped" pelvis
> No No No Yes Unknown Hairless
> No No No Yes Yes Reduced canines
> Yes No No Yes Yes Parabolic maxilla
> Yes Yes Yes No No Arms longer than legs
> No Yes No No Robusts Sagittal crest
>
> The list is selective, based as it is on obvious gross morphological
> features that a layman like me can identify. But its message is clear:
> the idea that a bipedal LCA separately evolved into orang-like & chimp
> / gorilla-like descendants is vastly less parsimonious than the
> alternative hypothesis, that an australopithecine biped (whether
> terrestrial or a wader) evolved from a chimp-like ancestor.
Clearly you're right that the model is less parsimonious. But there is
no fossil data for a k-w that was ancestral to Pan/Homo (4) whereas
there is evidence that the LCA (4 again) was bipedal. Parsimony is
fine in the absence of other evidence but I'd argue that the evidence
favours the bipedal LCA more than it does a k-w-ing LCA at the moment.
> However, the genetic evidence is that Pan is more closely related to
> Homo than either is to Gorilla. Revising the cladogram to coincide
> with the genetic evidence, I get this:
>
> /---------------------------------- Old World Monkeys
> /
> (1)- /--------------------------- Hylobatids (gibbons)
> \ /
> \-(2)- /-------------------- Pongo (orang utan)
> \ /
> \-(3)- /-(8)----- Gorilla (gorilla)
> \ /
> \ / /- Pan troglodytes
> \ / / (chimpanzee)
> \-(6)- /-
> \ / \ Pan paniscus
> \-(7)- \- (bonobo)
> \
> \---- Homo (humans)
>
> This makes the hypothesis of the wading biped even less parsimonious
> than the first cladogram, because it requires an australopithecine
> biped, at (6), to evolve into gracile (7) & robust (8) forms, which
> separately evolve into knuckle-walking apes. This means that the suite
> of ape-like features the 3 great ape genera share evolve independently
> 3 times.
Again, I agree. It's less parsimonious. However, first of all there's
the evidence argument again as above and secondly there's the opoint
that a'piths might not have been ancestral to Pan or Homo - very
likely actually.
> So: that's my straw man. If Algis or Marc are going to continue to
> promote the hypothesis of a wading bipedal ancestor of knuckle-walking
> great apes, they will have to tear down my straw man, & produce an
> alternative to my list of comparative features, & show how & why their
> view is more parsimonious. They will also need to show why the genetic
> evidence, that chimps & bonobos are closer to humans than to gorillas,
> is wrong...
I can't 'tear down' your staw man - just point out, respectfully, that
the evidence from Orrorin and Sahelanthropus is that they were already
at least partly bipedal and that these may well have preceded the LCA
of Pan/Homo as indicated by many studies using molecular data.
I put it to you that for your counter-argument to be correct, then the
molecular data *must* be wrong. As Jason and other have pointed out,
perhaps too much confidence was placed in the molecular data - but the
distinct possibility remains that it could be correct. As far as I can
see the only thing that has changed since much of it was published is
those very fossil discoveries that seem to court so much controversy.
To quote just one reference with other citations within...
Gagneuz et al 1998 "The divergence patterns in our results are in
general agreement with current hominoid divergence time estimates (in
millions of years ago) that are based on numerous sequences, methods
and assumptions, with the caveat that the ages of the major chimpanzee
clades have been underappreciated: orangutans, 12.5 mya (range 8-15);
gorillas 7.7 (6.6-10.0); hominids 4.7 (4.2-5.5); bonobos 2.5
(2.0-3.0); eastern & western gorillas > 2.5; the two species of
orangutan 1.7 (0.6-3.4); and the two major clades of chimpanzees
(western, central & eastern) 1.6. (Refs Ruvolo N (1997) Mol Biol Evol
14 248-265,Horai S, et al 1995 PNAS 92 532-536,Ruvulo et al 1993 Mol
Biol Evol 10, 1115-1135,Morin et al 1994 Science 265 1193-1201)"
Gagneux, Pascal, Wills, Christopher, Gerloff, Ulrike, Tautz, Diethard,
Morin, Phillip A, Boesch, Christopher, Fruth, Barbara, Hohman,
Gottfried, Ryder, Oliver A, Woodruff, David S (1999). Mitochondrial
sequences show diverse evolutionary histories of African hominoids.
Proceedings of the National Academy of Sciences of USA Vol:96
Pages:5077-5082
Algis Kuliukas
Jason Eshleman
Algis Kuliukas <al...@RiverApes.com> wrote:
>rmac...@alphalink.com.au (Ross Macfarlane) wrote in message news:<18fa6145.03052...@posting.google.com>...
>> It's more than just knuckle-walking - the changes required to produce
>> a biped are enormous. Both gorilla & pan re-evolved opposable big toes
>> from australopithecines who had lost them? Both evolved
>> rearward-facing foramen magnums?
>>
>> And you call this scenario more parsimonious?
>
>And yet it is still possible. There is no evidence whatsoever for a
>knuckle-walker that predates 3.5 my and yet you (presumably) have no
>problem in assuming that a'piths were ex-knuckle walkers on the way to
>human-like bipedalism. There is quite a bit of evidence for a bipedal
>LCA (Orrorin and Sahelanthropus dated at 6 and 7 mya, respectively and
>a body of evidence which might indicate a LCA dated at about 5mya.)
You are confusing no fossil forms with "no evidence whatsoever." The two
are *not* the same thing. Please be aware of this as your statement, as
you've made it, is simply false.
There is evidence of a knucklewalker prior to 3.5 mybp. The probable
phylogenetic affinities of apes and apiths make it rather reasonable to
assume that the LCA of humans and chimps (and likely gorillas) was a
knucklewalker. The morphological characteristics of humans, when compared
to chimps, gorillas and orangs and gibbons, also appear to support this.
That some apiths, creatures that share synapomorphies with humans relative
to apes, share a particular trait, an apparently non-functional trait,
otherwise only found in knucklewalking apes, further makes it likely that
this trait predates the 4.2 million year old species it has been
identified in.
This is not "no evidence whatsoever." You are presenting a falsehood to
suggest otherwise.
>The earliest 'aquarboreal' apes need not have been as specialised for
>bipedalism as you seem to assume.
>
>I am not arguing that a'piths were ancestral to Pan/Homo but I have an
>open mind to the possibility. The opposable toe and other reversals
>suggest that this is a less parsimonious model, I agree - but that
>does not prove it.
It's not just the reversals. It's the lack of shared, derived
characteristics as well. Apiths do share derived characteristics with
humans. These characters are derived when you look at all extant
non human hominoids, hell, virtually all cercopithecoids as well, and
derived relative to mid-miocene hominoids. I'm not sure what you mean as
far as being "open to the possibility" but the evidence strongly indicates
that whether or not you're open to the possibility, apiths were not
ancestral to the extant apes. It's simply not parsimonious, it's highly
unlikely. It makes the phylogenetic charachter evolution a total mess.
This isn't about some touchy feely "be open to the possibility." This is
about having good evidence that as stands, allows us to firmly reject the
hypothesis that apiths evolved into extant apes, and to accept the
hypothesis that they were part of the same clade (relative to chimps and
gorillas) as Homo.
>> > Whatever. How do pandas or chalictheres contracdict our scenario??
>>
>> The evidence about chalicotheres & ground sloths contradicts 2 strands
>> in your scenario: comparative evidence, & evidence that knuckle
>> walking pan & gorilla evolved from waders.
>
>> I gave you comparative evidence of terrestrial knuckle-walkers, who
>> evolved from probable terrestrial and arboreal ancestors, as models
>> for Gorilla & Pan. Now you give me 2 knuckle-walkers who evolved from
>> waders, as models for Gorilla & Pan.
>
>Absence of evidence is not...
Bingo. Yet you seem to take the absense of evidence of a fossil
knucklewalker to mean something. You want to revise your position here
now?
>> If you cannot, why should we
>> accept your arguments that they evolved from waders?
>
>You should have an open mind to it because:
>a) There is no evidence of knuckle-walking preceding a'piths
See above. You are again confusing "fossil evidence" with "evidence."
>b) There is evidence of bipeds preceding a'piths and k-w-ers
Yes, but this evidence is far from unambiguous. The evidence from Orrorin
is still a bit sketchy. The most diagnostic bits that would seal the deal
for bipedalism haven't been found. The morphology of the femur
indicates bipedalism can't be ruled out, but neither is it a sure thing
that the creature was bipedal.
>c) Exatnt apes do wade and do use their knuckles for support on the
>water margins and when getting out of the water.
Extant apes are knucklewalkers. One would expect them to use their
knuckles for support *regardless* of whether or not this had anything to
do with the origins of such activity.
Algis, you keep telling people they need to have an open mind, but this
seems to include accepting things for which there is strong counter
evidence. To accept your wading to knucklewalking transition, you have to
totally ignore strong phylogenetic evidence in favor of far less probable
phylogenies that explain far far far less. You also have to ignore what
we know about the morphology of creatures that use their arms for support.
I realize you try to downplay this by saying it was just an itty bitty
amount of support but you do this in a strange manner as well, somehow
making water so shallow that isn't supporting the creature magically
support the creature. It's very strange.
Spiznet
>
> And yet it is still possible. There is no evidence whatsoever for a
> knuckle-walker that predates 3.5 my and yet you (presumably) have no
> problem in assuming that a'piths were ex-knuckle walkers on the way to
> human-like bipedalism. There is quite a bit of evidence for a bipedal
> LCA (Orrorin and Sahelanthropus dated at 6 and 7 mya, respectively and
> a body of evidence which might indicate a LCA dated at about 5mya.)
>
> The earliest 'aquarboreal' apes need not have been as specialised for
> bipedalism as you seem to assume.
>
> I am not arguing that a'piths were ancestral to Pan/Homo but I have an
> open mind to the possibility. The opposable toe and other reversals
> suggest that this is a less parsimonious model, I agree - but that
> does not prove it.
>
> >
> > /---------------------------------- Old World Monkeys
> > /
> > (1)- /--------------------------- Hylobatids (gibbons)
> > \ /
> > \-(2)- /-------------------- Pongo (orang utan)
> > \ /
> > \-(3)- /-(8)----- Gorilla (gorilla)
> > \ /
> > \ / /- Pan troglodytes
> > \ / / (chimpanzee)
> > \-(6)- /-
> > \ / \ Pan paniscus
> > \-(7)- \- (bonobo)
> > \
> > \---- Homo (humans)
> >
Algis-
I know I am new to this discussion, but I am having trouble with the
reason why you are intertwining 2 "heretical" hypotheses:
1) A'pith related to apes
2) Human aquatic past.
It seems like you could argue one or the other, but the 2 do not mesh
well and certainly do not support each other.
Point 1: If Homo did have an aquatic evolutionary phase, (and if
aquaticism had anything to do with bipedalism) why not hypothesize
that this occured AFTER the LCA Gorilla/Pan/Homo. This would avoid
needing a bipedal LCA, and the devolution of all bipedal AND aquatic
traits in apes.
Point 2: All the aquatic adaptations you point out could have occurred
as late as homo, and could be due to the exploitation of rivers and
lakeside environments, which noone has ever disputed.
Point 3: A'piths are much too late (4-2mya) to be LCA apes or evolving
non-hominid apes, aren't they. I think that if there was any
possibility at all that they could be classified this way, the
literature would have supported this over the disturbing view of them
being homo ancestors.
Point 4: What about those Miocene apes? Weren't they knuckle walking?
Is there evidence in them of bipedalism, or did they go around on all
fours?
Marc Verhaegen
"Ross Macfarlane" <rmac...@alphalink.com.au> wrote in message
news:18fa6145.03052...@posting.google.com...
> Can you present any credible scientific evidence that suids (members of
the pig family) were ever "aquatic"?
The question is not whether humans were aquatic. The question is whether
human ancestors evolved on the savanna or at the seaside.
(snipped some blabla on round bones & so-called "KWing" calichotheres)
> It's more than just knuckle-walking - the changes required to produce a
biped are enormous.
Nothing is required to produce whatever. There's no goal in evolution.
> Both gorilla & pan re-evolved opposable big toes from australopithecines
who had lost them?
We've discussed this: the difference between an orang foot & a gorilla foot
is much larger than that between a gorilla & a human foot. Apith feet are
generally more like Afr.ape than like human feet. Still waiting for your
answer on R.J.Clarke 2000 "What the StW 573 Australopithecus skeleton
reveals about early hominid bipedalism" AAPA abstracts:126 "...that the foot
had both bipedal & climbing capabilities, whilst the arm & hand indicate
adaptation to arbor.locomotion. This skeleton's foot morphology is
consistent with the bipedal Laetoli footprint trails, which are not those of
fully human feet, but which have very clear ape-like morphology."
> Both evolved rearward-facing foramen magnums?
Making up your own facts as usual? Young gorillas & chimps have foramina
magna more ventral than adults, eg, well within the range of A.africanus
Sts-5, eg, Schultz 1955. Even in adults, the foramen has the same position
indices in gracile Sts-5 & robust ER-406 apiths as in bonobos, eg, Kimbel
cs.1984 table 9. Not unlikely the hominid LCA had a foramen magnum located
about as in bonobos.
> > Ever thought why Turkana Boy was so dissimilar from modern humans, eg,
why he had vertebral height much lower than any modern population?? Clear?
> Have thought about that, yes. Results from him having more "primitive"
condition - i.e. hasn't evolved the longer vertebral height seen in modern
humans. In fact his vertebral configuration is transitional between
australopiths & modern humans
Ah? Is it? As usual making up your "facts"?
> - as one would expect if his species (let's call it early Homo erectus)
had evolved from an australopithecine - or from an a'pith ancestor - and H.
sapiens had evolved from early H. erectus. Comment?
Refs please for your "facts".
> Surely you don't wish to claim that OH-62 / Lucy are more human-like than
the Turkana boy?
Why should I? Do you?
> Do you agree that early Homo (erectus / ergaster - e.g. the Turkana boy)
had a lower humerus to femur length ratio than australopithecus (afarensis
*or* africanus)?
Likely, yes. As is to be expected in our scenario.
> Your scenario requires unevolving bipedal hominid feet, hips, skulls etc.
in 3 distinct lineages (Pan & Gorilla), and possibly Pongo as well. How do
you make this parsimonious?
1) My scenario does not require this.
2) Never heard of parallel evolution? Extremely frequent.
> > Forgot that gorilla rel.arm length is more like human than like orang
rel.arm length??
> Factually erroneous claim, made without supporting data. Gorilla
humerus-femur ration is >110%; so is orang utan. Human is <90%. Agreed?
I'm not talking about humerus/femur ratios. Again: Forgot that gorilla
rel.arm length is more like human than like orang rel.arm length??
> Forget that gorilla hips, feet, skulls, vertebra, hands are more
orang-like than human-like??
Sigh. Man, you're hopeless: making up your "facts".
- General skeletal form: hips yes, feet no, skull yes, hands no, see
Schultz.
- In detail: probably no (see Gibbs, collard & Wood 2002 "Soft-tissue
anatomy of the extant hominoids..." J.Anat.200:3-49.
> A change in long bone length could be caused by a single point mutation.
How many does it take to move a foramen magnum from rearward to
downward-facing, & back again?
Why don't you answer your ridiculous "question" yourself?
> > > What boisei arm bone fossils are you referring to?
> > You can find it here
http://allserv.rug.ac.be/~mvaneech/Fil/Verhaegen_Human_Evolution.html Again:
inform before writing nonsense. You're so terribly biased.
> Where here? Please provide an exact scientific reference - author, paper,
page number.
See above. Do you own homework.
> > *Wrong*!! Lucy probably had much shorter arms than OH-62.
> Cite a ref. Otherwise I'll continue to rely on the refs. I've read, which
tell me that given the poor state of preservation of OH-62, & the fact that
it's only a single fossil, there is no statistical difference between Lucy &
OH-62.
Of course.
> Note: if there's no statistical difference, then in a scientifically
pedantic sense, Lucy's arms were "probably" not shorter than OH-62's.
You're the pedant: "probably" here only means: we've only 1 specimen to
compare. From the above website: "Lucy's arms were much shorter than a
bonobo's (humerus 24 cm vs 29 cm; cf. 26 cm in human pygmies) and lacked
knuckle-walking adaptations (Jungers, 1982; Stern & Susman, 1982), but later
the small hominid O.H.62 had more chimp- and bonobo-like proportions (Korey,
1990; Aiello & Dean, 1990, p. 258; Wood, 1992, box 2),..."
> > > > Not following? Point: spider monkeys are not bipedal. Not following?
Point: spider monkeys are not apes.
> > That's no point.
> The point is clear to all but you Marc. Spider monkeys are not apes.
Yes, apparently you believe that apes are chalicotheres.
> Therefore they exhibit different adaptations to brachiation and bipedality
/ quadrupedality to gibbons & other apes. Your comparative evidentiary
methodology, taken to extremes, could imply that brachiation could only
evolve in a primate which had a long prehensile tail.
Don't be ridiculous.
> My point is that the evolutionary history of an ape constrains it to
develop in different ways from spider monkey, & therefore the comparison of
bipedality in hylobatids to quadrupedality in spider monkeys is invalid. OK?
Not OK. That's the usual just-so stories of traditional PAs.
> *How*, *when*, and *why* would a obligate bipedal aquarboreal wader
knuckle-walk?
What on earth is an obligate bipedal aquarboreal wader??
> ("When" meaning when on any given day, not when in evolutionary history.)
??
> Can you tear down the cladistic straw man I presented, as follows? - I
started by overlooking the genetic evidence to the contrary, & assumed that
Pan is closer to Gorilla than Homo. That led to the following cladogram for
extant apes & modern humans:
>
> /---------------------------------- Old World Monkeys
> /
> (1)- /--------------------------- Hylobatids (gibbons)
> \ /
> \-(2)- /-------------------- Pongo (orang utan)
> \ /
> \-(3)- /---- Gorilla (gorilla)
> \ /
> \ /-(5)- /- Pan troglodytes
> \ / \ / (chimpanzee)
> \-(4)- \-
> \ \ Pan paniscus
> \ \- (bonobo)
> \
> \--------- Homo (humans)
Man, I've given our scenario many times:
0) early anthropoids: arboreal (climb)
1) early hominoids: aquarboreal (??climb+swim ?flooded forests)
2) early hominids: aquarboreal (climb+wade)
3) early Homo: seaside (Algeria-Java c.1.8 Ma)
4) sapiens: terrestrial (but still "waterside", just see our bathrooms)
> Algis & Marc hypothesise that the Gorilla / Pan / Homo last common
ancestor (4) was a wading biped. But (4) shares a LCA with Pongo at (3). So
either the wading biped evolved after this split, or (3) was more similar to
the wading biped. Either way, any similarities between orang utans & African
great apes would be due to convergent evolution.
Not any. Several, yes, of course.
> So, to test if it is more parsimonious to assume that the LCA at (4) was
more like a bipedal australopith, or a knuckle-walking great ape, I came up
with the following straw man of features:
Pongo Gorilla Pan Homo A'pith Feature
===============================================
No Yes Yes No No Knuckle-walking
Wrong: apiths had some KWing features.
Yes Yes Yes No No Grasping foot
Wrong: see above Clark.
Yes Yes Yes No No Opposable toe
Idem.
No No No Yes Yes Obligate biped
Wrong: Afr.apes regularly walk bipedally. The term "obligate biped" alon
shows your bias.
No No No Yes Yes "Bowl-shaped" pelvis
Genrally ape pelvises are as derived as human pelvises.
No No No Yes Unknown Hairless
No No No Yes Yes Reduced canines
"Reduced" shows your bias. Inform, my boy: from the above website: "The
pronounced prognathism and large incisors and very large canines of the
adult males of G. gorilla and P. troglodytes are thought to exclude
australopith ancestors, since most robust australopiths had "flat" faces and
(at least in comparison with their enormous back teeth) small anterior
teeth. But this evidence is not conclusive: (1) A. afarensis and A.
africanus also possessed moderately projecting canines ... (2) even in
robust australopiths (SK 23, Natron, L.7-125), the indices of the basic
rectangle of the mandible are within the range of these of common chimps but
outside those of humans (Kinzey, 1970); ... (5) bonobos "have relatively
small and only slightly dimorphic canine teeth" (Zihlman et al., 1978); (6)
"infant great apes have flat or orthognathic faces like modern humans"
(Aiello & Dean, 1990, p, 197); (7) some specimens of H. erectus had
maxillary diastemata of 6 mm, as large as an orang's (Howells, 1959, p. 157;
Rensch, 1972, p. 36), and much larger than in the robust australopiths (who
lived earlier); (8) selection for larger or smaller teeth can theoretically
occur in very short evolutionary periods (cf. Silson, 1988, p. 19), and is
claimed to have been demonstrated in only a few thousand years in human
populations (Calcagno & Gibson, 1988); (9) the marked difference in
prognathism between Negroes and Whites (e.g. Howells, 1959, p.269; Kinzey,
1970, fig. IA-B) developed in a time span of only about 200,000 years (Cann
et al., 1987; Vigilant et al., 1991). Moreover, it is not very likely
that the primitive African hominoid condition included ape-like pronounced
prognathism and very long canine teeth. See, for instance, Kinzey's (1970)
comparisons of the basic rectangle of the mandible in different Haplorhini
(in Kenyapithecus africanus, e.g., it resembles Homo rather than Pan), or
the anatomy of the face in infant chimpanzees (orthognathism with relatively
short milk canines and vertical mandibular symphysis)."
Yes No No Yes Yes Parabolic maxilla
Idem.
Yes Yes Yes No No Arms longer than legs
Wrong: Lucy probably had rel.hort arms & legs. Humans evolved longer legs.
Apes (orangs>bonobos>chimps>gorillas) evolved longer arms.
No Yes No No Robusts Sagittal crest
OK.
(rest snipped: nonsense: based on "own facts" as I showed)
Marc Verhaegen
http://www.onelist.com/community/AAT
http://allserv.rug.ac.be/~mvaneech/Verhaegen.html
Marc Verhaegen
"Jason Eshleman" <j...@vici.ucdavis.edu> wrote in message
news:baivgp$q01$1...@woodrow.ucdavis.edu...
> There is evidence of a knucklewalker prior to 3.5 mybp.
?? The man is making up his own facts. This seems to be a common dry ape
tradition.
Fact: There's rather good evidence of A.anamensis having a few features
typically seen in KWers.
> The probable phylogenetic affinities of apes and apiths make it rather
reasonable to assume that the LCA of humans and chimps (and likely gorillas)
was a knucklewalker.
Rubbish. There's no evidence whatsoever that humans ever had KWing
ancestors. If the hominid LCA was a KWer this would require the mysterious
complete disappearance of every KWing trait in humans. OTOH parallel
evolution is extremely frequent in evolution. From one of my Hum.Evol.papers
http://allserv.rug.ac.be/~mvaneech/Fil/Verhaegen_Human_Evolution.html :
"Biomolecular results leave no doubt that Pan is genetically closer to Homo
than to Gorilla (e.g. Goodman, 1982; Hasegawa et al., 1985, 1987, 1988;
Caccone & Powell, 1989; Sibley et al., 1990; Gonzalez et al., 1990; Ruvolo
et al., 1991; Begun, 1992), and contrary to the prevailing opinion this is
not contradicted by the anatomical evidence (Groves & Paterson, 1991). This
implies that the African hominoids first split into Pan-Homo (smaller,
relatively gracile) and Gorilla (larger, super-robust), and that many of the
traits that common chimps share with gorillas but not with bonobos or humans
could have developed in parallel with gorillas (e.g. very long and sexually
dimorphic canines, "very" dorsal foramen magnum, ectocranial crests, arms
considerably longer than legs). Convergent and parallel, even reverse or
fluctuating evolution of anatomical traits are among the commonest features
of biological evolution (e.g. Trinkaus, 1990; Hartman, 1989; Sheldon, 1988;
Seger, 1987; Gibbs & Grant, 1987; Cartmill, 1982; White & Harris, 1977;
Darwin, 1903, p.171), and the final proof that Darwinism is not a tautology.
"Parallel evolution occurs when two species adopt a lifestyle that is more
or less similar. If the lifestyle is essentially identical, and the species
from a similar genetic background, the end result may be almost
indistinguishable to other than detailed examination" (R. G. Silson, pers.
comm.)."
(no time to read the rest of Eshleman's fairy tales)
Jason Eshleman
>
>> \-(3)- /---- Gorilla (gorilla)
You are doing a curious thing, Algis: you are taking Orrorin, a little
known creature from about 6my with questionable phylogenetic affinities
who may have--but may not have--been bipedal, and saying that this is
evidence for bipedality before the chimp human LCA based entirely on
molecular estimates of a split at approx 5 mybp. You are hinging an
argument on an interpretation of a femur that, while possibly an indicator
of bipedality, certainly isn't a done-deal and very dubious molecular
dates, ones that have assumed rather tautological circularity and have
error rates that make them useless for such fine level hypothesis testing.
You do this while ignoring more recent molecular estimates (ones not at
all inspired by Orrorin, but came from studies started long before this
find) that suggest, on the basis of better calibration, that the C-H split
was actually older than the 5my spit.
Meanwhile, you're ignoring the evidence that the LCA was a knucklewalker,
evidence derived from comparative anatomy of extant hominoids (see
Knuckle-walking hominid ancestors, Journal of Human Evolution, 40:507-511
Robert S. Corruccini and Henry M. McHenry (2001)). While you may consider
molecular data with high associated error rates based on questionable
calibration points to be worth more than the morphological comparisons, to
say that there's not any evidence of a knucklewalking at the LCA is false.
Yet you hinge your rejection of a parsimonious phylogeny on these
questionable assumptions. Why?
From some questionable data, you hypothesize a LCA that was bipedal and
say that there's evidence for it. Evidence, perhaps, but rather dubious
evidence when we do not know with certainty A) if Orrorin was bipedal, B)
if it was ancestral to later bipeds and/or knucklewalking apes, and C) if
it existed before or after the chimp human LCA. The evidence for A, B,
and C is sketchy. It may be so, but please stop treating it like it's so
damn good and the evidence for a knucklewalking LCA is so damn poor.
That's simply not the case.
Very likely, but the evidence supports that they were more closely related
to humans than to chimps. We likely see few ancestors, but this doesn't
mean that we aren't seeing individuals more closely related, in our clade
relative to chimps.
>> So: that's my straw man. If Algis or Marc are going to continue to
>> promote the hypothesis of a wading bipedal ancestor of knuckle-walking
>> great apes, they will have to tear down my straw man, & produce an
>> alternative to my list of comparative features, & show how & why their
>> view is more parsimonious. They will also need to show why the genetic
>> evidence, that chimps & bonobos are closer to humans than to gorillas,
>> is wrong...
>
>I can't 'tear down' your staw man - just point out, respectfully, that
>the evidence from Orrorin and Sahelanthropus is that they were already
>at least partly bipedal and that these may well have preceded the LCA
>of Pan/Homo as indicated by many studies using molecular data.
>I put it to you that for your counter-argument to be correct, then the
>molecular data *must* be wrong. As Jason and other have pointed out,
>perhaps too much confidence was placed in the molecular data - but the
>distinct possibility remains that it could be correct.
There's a distinct possibility (a highly likely one in my opinion) that
it's wrong though.
>As far as I can
>see the only thing that has changed since much of it was published is
>those very fossil discoveries that seem to court so much controversy.
Then you haven't done much research on the molecular data.
I strongly caution you against using the crutch that it is only with the
discovery of Orrorin that people started seriously questioning the
molecular dates. That is entirely false. Note that Arnason et al.
published divergence times in 2000 that suggest a Pan-Homo split in excess
of 10mybp. Note that they have a considerable discussion of the
controversies in the dating, a discussion written before Orrorin was
brought to light. To hide behind the "it's only because Orrorin that
people are questioning the molecular data" is again simply false.
Marc Verhaegen
"Algis Kuliukas" <al...@RiverApes.com> wrote in message
(I completely agree with Algis on the snipped)
> I suggest that ostrich wings have *some* function. Clearly it is not for
flight and I don't know enough about ostriches to guess what it might be
but - not *nothing.*
Yes. Might be, eg, help in equilibrium. Or display?
> The vestigial argument for the notches in a'piths argues that they had *no
function* I think it is far more likely that they had some function. I'm not
suggesting that it was full weight-bearing knuckle-walking as we see in
Pan/Gorilla today - I thank Jason for helping me to see that - but that it
might have been an early manifestation of its evolution, perhaps to help
support the body whilst feeding.
Yes, that's 1 of the possibilities, eg, when feeding on sedges at the
waterside, leaning upon more solid ground. Or when coming out of the swamp
(possibly still had rel.shorter arms). Or leaning in very shallow water, as
gorillas still do. Or the notches could have had other functions: functions
can change through evolution. eg, stabilising the hand for whatever reason.
Marc Verhaegen
"Bob Keeter" <rke...@earthlink.net> wrote in message
news:WTYva.69545$4P1.6...@newsread2.prod.itd.earthlink.net...
> > > Think that he could shoot for "No lo contendre"?
> > bk, not only PA is a bit difficult for you, but Spanish apparently also.
Wovon man nicht sprechen kann, darueber muss man schweigen.
> PA is difficult but not impossible, but I can tell the difference between
poor Latin (I had inserted an extra space) and worse Spanish.
Typical dry ape talk. For some reason they like to insert extra spaces. Not
only "no lo" for "nolo" is nonsense, but also "contendre" is no Latin.