hominid diet
Marc Verhaegen
>Paul Crowley
>It is probable that robusts and graciles occupied closely parallel niches.
They shared unique characteristics -- bipedalism, manipulative ability,
large brains, hard teeth, and no doubt much else; their divergence was
recent and probably no more than a matter of geography.
- australopith bipedalism: not the fully developed human bipedalism, but
short-legged wading bipedalism, somewhat more than in walking or wading apes
& proboscis monkeys
- manipulative ability: probably not (much) more than in apes or panda bears
manipulating bamboo or raccoons or (sea)otters, not the human independence
of index finger & fingers 3-5
- large brains: australopiths did not have (much) larger brains than apes &
were apelike in all respects as far as we know
The difference of gracile (earlier) vs robust australopiths (2-1mya) was
possibly due to the Pleistocene cooling: more open country, less trees, less
soft fruits & herbs. Possilby africanus evolved into robustus at about the
same time when afarensis evolved in boisei (synchronous parallel evolution
due to the same climatic changes?).
The biggest difference is not that between robust & gracile australopiths,
but that between australopiths & Homo.
>In the hominid family we have several species with a truly astonishing
adaptation -- bipedalism!
We must make a distinction between bipedalism that is seen in all primates
that go wading (proboscis monkeys wade in mangrove forests but also walk &
run bipedally on land, macaques on the beach, lowland gorillas in swamps,
bonobos & other apes occasionally) & our present-day & rather recent
long-legged & fully erect bipedalism.
>> Please give an alternative theory.
>>
>I've posted it here many times before, but once more for your benefit: I
believe that it was shellfish-eating, primarily on the marine littoral.
Yes, no doubt, see my papers & book.
But maybe only Homo & not australopiths.
Or maybe the australopith proneness to eat hard woody plants (nuts, reed &
babmboo stalks?) could have been preadapted by earlier small bivalve
crushing (last common ancestor of (only African?) great hominoids?).
Walruses don't have thick enamel, but suck mussels etc., but sea-otters seem
to have thick enamel.
Marc
Norman K. McPhail
crow...@hotmail.com wrote:
>
> "Marc Verhaegen" <Marc.Ve...@village.uunet.be> wrote:
>
> > - australopith bipedalism: not the fully developed human
> > bipedalism, but short-legged wading bipedalism, somewhat more
> > than in walking or wading apes & proboscis monkeys
>
> not. Let me suggest some tests: (a) Could males wield clubs and
> use stones as weapons?
I would like to suggest that the mere ability to use sticks and stones
as weapons is a long way from the regular use of these inventions as
substitutes for fangs and claws. Most great apes can and do fashion
branches as tools to fish for termites and they are known wield sticks
as weapons. They also are known to use rocks to crack open nuts. And
they can be regularly seen throwing all kinds of things for defense and
to express their hostility.
So I'm not sure how the mere use of sticks and stones might relate to
bipedalism. On the other hand, if they used these weapons regularly in
hunting and defense, they would need to carry them around with them.
But regular use of these weapons would mean that there was a great leap
of foresight. They would need to understand that their lives depended
on having these weapons close at hand.
But then we get into a chicken and egg problem. Did they get in the
habit of carrying these weapons around with them because they were
bipedal? If so, all they had to do was remember to take their weapons
with them. That would enable those who were smart enough to think ahead
a little to survive the arms race with the predator cats and dogs.
Or was it those apes who were willing to endure the pain of walking
upright that were able to pass their genes on to the next generation.
Perhaps it was some of both. And don't forget that even females who
were burdened with infants would need to protect themselves and their
offspring with these weapons.
> (b) Could infants grip their mothers'
> hair (or sides) with the feet and arms in the same way as normal
> primates?
If their mothers didn't have much body hair, it would mean that they
would need to carry their babies the same way we do. Males could and
probably did carry youngsters too. Have you ever gone hiking with your
kids?
Again, it's important to consider how our forebears dealt with these
problems, but I'm not sure any single answer leads to a conclusion about
bipedalism. It seems to me that we might get a better sense of how all
these things relate to each other if we keep asking more questions and
linking all the problems into a mass to see how things might have
evolved.
> (c) Could females with infants run, climb, fight and
> defend themselses as well as normal primates?
Another good question that deserves a lot of thought. The answers here
might relate to the wide range of love stories we humans are capable of
participating in. Our complex courtship patterns and social structure
seem to suggest that groups of hominids could vary the patterns to fit
the conditions they had to face.
> > - manipulative ability: probably not (much) more than in apes
> > or panda bears manipulating bamboo or raccoons or (sea)otters,
> > not the human independence of index finger & fingers 3-5
>
> Their hands seem to me to be almost human. They certainly had
> opposable thumbs. They had just lost their large canines so
> they must have acquired other weapons -- and these were
> obviously the regular use of clubs and stones. The density of
> their skulls and development of large eyebrow ridges is further
> evidence.
>
> Once a animal starts to use hand-held weapons it is effectively
> impossible that it cease their use, and then re-grow large
> canines.
>
It may be unlikely that our forebears could retrace their genetic steps
and revert back to genetic weapons such as claws and fangs. But there
are lots of cases of species reverting back to old traits to stay in the
game of life. So again I would say that it was not so much the use of
these weapons that was significant, it was that they could imagine the
use of a stick or rock for their own benefit. I think it was this
understanding that was the big breakthrough.
And once they caught on that they could solve problems like their lack
of claws and fangs in their heads instead of waiting for their genes to
to give them these weapons, they would be likely to depend more and more
on their brains. But this meant that they had to recognize that they
were no match for the big cats and other predators that threatened
them. And then they had to grasp the fact that a stick or stone could
serve as a substitute for fangs and claws.
So I think it was this mental leap that would be hard to reverse once
they started to depend on their wits. Then it seems likely that sexual
selection would likely reinforce selection for both physical and mental
fitness. This is the kind of massive multiple selection pressure for
smart choices that might begin to hint at why our forebears neo cortex
quadrupled in size in just 2.5 million years.
> > The difference of gracile (earlier) vs robust australopiths
> > (2-1mya) was possibly due to the Pleistocene cooling: more open
> > country, less trees, less soft fruits & herbs. Possilby
> > africanus evolved into robustus at about the same time when
> > afarensis evolved in boisei (synchronous parallel evolution due
> > to the same climatic changes?).
>
> An evolutionary explanation based on climatic change is the
> first resort of a bad paleontologist (agreed there are an awful
> lot of them). Reduced resources just kill populations off.
> Why should dryer, colder conditions and an expansion of
> grasslands create more opportunities for a slow vulnerable
> hominid?
>
I'm a little suspicious of anyone who would brand a paleontologist good
of bad based on their views. It seems to me that climate changes along
with the resultant habitat changes could help explain some of the
physiological changes that species evidence. Certainly these changes
cause mass extinctions and migrations as well as significant changes in
many ecosystems.
And there is ample evidence that climatic changes triggered dramatic
changes in individual species. None of these changes occurs alone.
Still, climates, habitats, ecosystems and the species that occupy this
earth can and do change each other in an amazing vaieity of ways.
> > The biggest difference is not that between robust & gracile
> > australopiths, but that between australopiths & Homo.
>
> The difference between the robusts and graciles should be easy
> to explain -- mainly those gigantic, hyper-dense teeth. The
> reasons for the longer legs and larger brains of the homo line
> should not be too hard to see. Somehow they escaped the
> restraints of the initial hominid niche.
>
I prefer to think of the hominid as a generalist. From my point of
view, our forebears liked to live in the seams between major habitat
ecosystems. I think they were conmumate opportunists who liked to
straddle the margins between land and sea, forest and plain. The
beaches and the transition zone at the edge of the rain forest provided
them protection from their enemies in all these habitats. The water
provided a safe haven from land predators. The beach was an escape from
sharks. The trees also gave them a place to hide from the big cats and
dogs of the plains.
What's more, jumping between these multiple habitats gave them lots of
choices in what to eat. Think about it. Isn't adaptablilty something
we're really good at. But to me, all these choices meant that they had
to make good decisions. And again we come down to using their heads to
help them make all these choices.
> > We must make a distinction between bipedalism that is seen in
> > all primates that go wading (proboscis monkeys wade in mangrove
> > forests but also walk & run bipedally on land, macaques on the
> > beach, lowland gorillas in swamps, bonobos & other apes
> > occasionally) & our present-day & rather recent long-legged &
> > fully erect bipedalism.
>
> You left out the bipedalism exhibited by trained dogs or circus
> animals. They have about the same relevance.
>
Again, I'm suspicious of smart alec remarks like this. They often are
an attempt to cover up feelings or an intuition that we find hard to
articulate. There is a big difference in degree between mammals that
can walk around on two legs on occasion and those that walk on two legs
all the time. So far as I know, we are the only mammal that almost
always moves about on two legs.
From my perspective, the significance of the other apes and monkeys that
exhibit some bipedalism is that is demonstrates what may be partial
adaptations. We see these all the time in the wild. There are iguanas
in the Gallapagos who are paritally adapted to the marine environment.
There are also cormorants there whose wings are useless for flying, but
work fairly well as flippers. They are part way between the sea gulls
and the penguins.
It is not unreasonable to speculate that our forebears also went through
stages when their legs were partially adapted to bipedalism. And it is
not unreasonable to assume that aquatic adaptations were a part of this
transition to bipedalism.
> > But maybe only Homo & not australopiths [ate shellfish]
>
> I think that it's very important to have highly specific reasons
> as to why the first hominids went bipedal (given the enormous
> costs involved -- although I know you don't appreciate them).
Again, why the snide remark?
> Having a group of quasi-chimps start relying on a diet with
> large proportion of shellfish and stop sleeping in trees would
> be a major part of niche change.
>
Or a major part of the transition to becoming even more of a generalist.
> How do you explain australopith bipedalism?
>
> > Or maybe the australopith proneness to eat hard woody plants
> > (nuts, reed & babmboo stalks?) could have been preadapted by
> > earlier small bivalve crushing
>
> You're into promiscuous niche-swapping again. The evidence for
> the "proneness to eat hard woody plants" is negligible. The
> switch to such a diet by a frugivore animal is extremely
> unlikely.
>
Yet such a switch could become a necessity under the proper
circumstances.
> > sea-otters seem to have thick enamel.
>
> They have very large, hard, crushing teeth -- not unlike the
> robusts.
>
Regardless of their dentures, I think there is something very special
about sea otters. I have an intuitive sense that we share a lot with
them.
crow...@hotmail.com
"Marc Verhaegen" <Marc.Ve...@village.uunet.be> wrote:
> - australopith bipedalism: not the fully developed human
> bipedalism, but short-legged wading bipedalism, somewhat more
> than in walking or wading apes & proboscis monkeys
You need to decide whether the australopiths were bipedal or
not. Let me suggest some tests: (a) Could males wield clubs and
use stones as weapons? (b) Could infants grip their mothers'
hair (or sides) with the feet and arms in the same way as normal
primates? (c) Could females with infants run, climb, fight and
defend themselses as well as normal primates?
> - manipulative ability: probably not (much) more than in apes
> or panda bears manipulating bamboo or raccoons or (sea)otters,
> not the human independence of index finger & fingers 3-5
Their hands seem to me to be almost human. They certainly had
opposable thumbs. They had just lost their large canines so
they must have acquired other weapons -- and these were
obviously the regular use of clubs and stones. The density of
their skulls and development of large eyebrow ridges is further
evidence.
Once a animal starts to use hand-held weapons it is effectively
impossible that it cease their use, and then re-grow large
canines.
> The difference of gracile (earlier) vs robust australopiths
> (2-1mya) was possibly due to the Pleistocene cooling: more open
> country, less trees, less soft fruits & herbs. Possilby
> africanus evolved into robustus at about the same time when
> afarensis evolved in boisei (synchronous parallel evolution due
> to the same climatic changes?).
An evolutionary explanation based on climatic change is the
first resort of a bad paleontologist (agreed there are an awful
lot of them). Reduced resources just kill populations off.
Why should dryer, colder conditions and an expansion of
grasslands create more opportunities for a slow vulnerable
hominid?
> The biggest difference is not that between robust & gracile
> australopiths, but that between australopiths & Homo.
The difference between the robusts and graciles should be easy
to explain -- mainly those gigantic, hyper-dense teeth. The
reasons for the longer legs and larger brains of the homo line
should not be too hard to see. Somehow they escaped the
restraints of the initial hominid niche.
> We must make a distinction between bipedalism that is seen in
> all primates that go wading (proboscis monkeys wade in mangrove
> forests but also walk & run bipedally on land, macaques on the
> beach, lowland gorillas in swamps, bonobos & other apes
> occasionally) & our present-day & rather recent long-legged &
> fully erect bipedalism.
You left out the bipedalism exhibited by trained dogs or circus
animals. They have about the same relevance.
> But maybe only Homo & not australopiths [ate shellfish]
I think that it's very important to have highly specific reasons
as to why the first hominids went bipedal (given the enormous
costs involved -- although I know you don't appreciate them).
Having a group of quasi-chimps start relying on a diet with
large proportion of shellfish and stop sleeping in trees would
be a major part of niche change.
How do you explain australopith bipedalism?
> Or maybe the australopith proneness to eat hard woody plants
> (nuts, reed & babmboo stalks?) could have been preadapted by
> earlier small bivalve crushing
You're into promiscuous niche-swapping again. The evidence for
the "proneness to eat hard woody plants" is negligible. The
switch to such a diet by a frugivore animal is extremely
unlikely.
> sea-otters seem to have thick enamel.
They have very large, hard, crushing teeth -- not unlike the
robusts.
Paul.
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Marc Verhaegen
crow...@hotmail.com heeft geschreven in bericht
<6k2fgg$kfn$1...@nnrp1.dejanews.com>...
>"Marc Verhaegen" <Marc.Ve...@village.uunet.be> wrote:
>
>> australopith bipedalism: not the fully developed human
>> bipedalism, but short-legged wading bipedalism, somewhat more
>> than in walking or wading apes & proboscis monkeys
>You need to decide whether the australopiths were bipedal or not.
It's not all or nothing. They were bipedal in swamps (wading or sitting
erect while eating herbs, as lowland gorillas do). Proboscis monkeys on dry
ground sometimes run on all four, but more often on the hindlimbs alone, &
in water they wade bipedally or swim. In swamps or in dense vegetation you
can walk on your hindlegs & grasp reed or twigs with your hands while
progressing.
>Let me suggest some tests:
>(a) Could males wield clubs and use stones as weapons?
Even chimps brandish sticks, throw stones, crack nuts with stones, use twigs
as probes...
IMO australopiths did the same but no more.
>(b) Could infants grip their mothers' hair (or sides) with the feet and
arms in the same way as normal primates?
Probably. Sit on their mother's back as in chimps etc.
>(c) Could females with infants run, climb, fight and
>defend themselses as well as normal primates?
Probably. Why not? There is not very much human in australopiths.
(You're still talking about australopiths, not about H.erectus, are you?)
The australopith manipulative ability was probably not (much) more than in
apes or panda bears manipulating bamboo, perhaps even less than in raccoons
or (sea)otters. Certainly not the human independence of finger 2 vs fingers
3-5.
>Their hands seem to me to be almost human. They certainly had
>opposable thumbs. They had just lost their large canines so
>they must have acquired other weapons --
Why "must"? Herbivores like horses or capibaras or beavers don't have "large
canines or other weapons".
>and these were obviously the regular use of clubs and stones. The density
of their skulls
No dense skulls in australopiths! (Crests in robusts, yes, as in apes)
There's a big difference between australopiths (apelike walking, climbing,
wading, rudimentary tool use) & H.erectus/neand./sapiens (diving, full
bipedalism, tools)
>and development of large eyebrow ridges is further evidence.
In all mammals the eyes are protected by bone. The eyebrow ridge protects
the frontal eyes. Nothing special about that.
>Once a animal starts to use hand-held weapons it is effectively
>impossible that it cease their use, and then re-grow large canines.
Why do you think so?
The difference of gracile (earlier) vs robust australopiths (2-1mya) was
possibly due to the Pleistocene cooling: more open country, less trees, less
soft fruits & herbs. Possibly africanus evolved into robustus at about the
same time when afarensis or aethiopicus evolved in boisei (synchronous
parallel evolution due to the same climatic changes?).
>An evolutionary explanation based on climatic change is the
>first resort of a bad paleontologist (agreed there are an awful
>lot of them).
No, see, eg, Darwin's finches & fluctuating evolution (dryer vs wetter years
> selection of larger vs smaller beaks etc.). On oscillating or parallel
evolution in a changing climate see, eg, SE Hartmann 1989 AJPA 80:145, P
Sheldon 1988 NS 1596:52, J Seger 1987 Nat.327:461, Gibbs & Grant 1987
Nat.327:511, M Cartmill 1982 in Spencer ed. History of Am. phys.anthrop.
Academic NY, White & Harris 1977 Sci.198:13, Darwin 1903 Origin p.171)
> Reduced resources just kill populations off.
Perhaps temporary starvation & reduction, but why killing-off?
>Why should dryer, colder conditions and an expansion of
>grasslands create more opportunities for a slow vulnerable
>hominid?
?? (I didn't say that)
More opportunities? Changing diet: perhaps less soft fruits & more woody
plants etc.
>> The biggest difference is not that between robust & gracile
>> australopiths, but that between australopiths & Homo.
>
>The difference between the robusts and graciles should be easy
>to explain -- mainly those gigantic, hyper-dense teeth. The
>reasons for the longer legs and larger brains of the homo line
>should not be too hard to see.
Why do you think so?
>> We must make a distinction between bipedalism that is seen in
>> all primates that go wading (proboscis monkeys wade in mangrove
>> forests but also walk & run bipedally on land, macaques on the
>> beach, lowland gorillas in swamps, bonobos & other apes
>> occasionally) & our present-day & rather recent long-legged &
>> fully erect bipedalism.
>
>You left out the bipedalism exhibited by trained dogs or circus
>animals. They have about the same relevance.
No, see photos & films of standing/walking/wading bonobos, lowland gorillas
& proboscis monkeys in the wild.
>I think that it's very important to have highly specific reasons
>as to why the first hominids went bipedal (given the enormous
>costs involved -- although I know you don't appreciate them).
>Having a group of quasi-chimps start relying on a diet with
>large proportion of shellfish and stop sleeping in trees would
>be a major part of niche change.
Isn't that what you call niche-swapping? All in one step is too much.
>How do you explain australopith bipedalism?
Wading primates, of course. See gorillas wading in swamps to get sedges, or
proboscis monkeys to reach other mangrove trees. The more they dwell in
swhallow water, the more bipedal they are.
>> Or maybe the australopith proneness to eat hard woody plants
>> (nuts, reed & bamboo stalks?) could have been preadapted by
>> earlier small bivalve crushing?
>You're into promiscuous niche-swapping again. The evidence for
>the "proneness to eat hard woody plants" is negligible. The
>switch to such a diet by a frugivore animal is extremely unlikely.
No: nuts, hard fruit exocarps, eg, A Walker 1981 Phil.Trans.R.Soc.Lond.B
292:57
(What I said was just a possibility: a gradual change from shells to hard
nuts or vice versa - mangrove capuchins eat both. I don't understand what
you have with "niche-swapping".)
>> sea-otters seem to have thick enamel.
>
>They have very large, hard, crushing teeth -- not unlike the robusts.
Yes, Walker 1981 thinks so. I'll ask other people who can know.
Do you think the robusts cracked small shells with their teeth? or did they
crack molluscs (including larger ones?) with stones & needed thick enamel
for the occasional hard inclusions in shellfish, see Walker 1981?
Whereas there are plenty of molluscs near Homo fossils (rudolf., ergaster,
early erectus), this is apparently not the case for the
Australopith.species, whether gracile or robust.
It seems that eating marshland plants (herbs, sedges, papyrus, reed,
bark...) sufficiently explains the typical dentition & the microwear
features of the Australopith.species (studies of PF Puech). This diet was
probably supplemented with fruits (soft fruits leave no traces, except the
etching of unripe fruits). The only indication for shellfish eating is the
thick enamel, which is present in nut-cracking primates, but perhaps also in
sea-otters.
Coypus (enamel resemblance with habilis) eat marshland plants like reed,
sedges, fruits, but also some shellfish.
Marc
Jim McGinn
Paul Crowley wrote in message <356773dc...@news.indigo.ie>...
<snip>
>While many
>primates have frugivorous/omnivorous diets (e.g. chimps.
>baboons, macaques) they keep their identity. We do not have to
>fully comprehend the reasons -- just accept the fact. Other
>species/genera do not niche-swap; species within the same
>genera stick to similar niches. We must not make an exception
>for hominids just to put together a story.
>
>Paul.
Yes! This is very well stated. I've been meaning to post a response similar
to this but I was afraid it wouldn't be appreciated in this newsgroup.
Jim McGinn
Paul Crowley
> On the other hand, if they used these weapons regularly in
> hunting and defense, they would need to carry them around with
> them. But regular use of these weapons would mean that there
> was a great leap of foresight. They would need to understand
> that their lives depended on having these weapons close at hand.
Why should the picking up of a weapon require such a high level
of consciousness? Foxes, magpies and squirrels don't
"understand" that they are laying up provisions for the winter
when they bury things. The ones that developed this instinct
prospered and the rest didn't. Why do you want to rule out
such a mechanism for hominids? Are we above instinct?
Chimps often use weapons. Frans de Waal describes how a young
chimp would not pass a cage containing a leopard unless he had
a strong stick in his hand. If that chimp had felt constantly
under threat, and if he had been better adapted for carrying,
and if he normally slept in the same place on the ground, then
there would have been little difficulty in keeping a stick with
him most of the time.
> But then we get into a chicken and egg problem. Did they get
> in the habit of carrying these weapons around with them because
> they were bipedal? If so, all they had to do was remember to
> take their weapons with them.
Those near-chimp australopiths (or near-chimp Ardpithecine-
Ramadines -- what's the right word here?) that got into the
habit of carrying a club survived; those that didn't got
beaten to death. Bipedalism in males would not have been hard
to develop. It's the females that we have to focus on.
>> (b) Could infants grip their mothers'
>> hair (or sides) with the feet and arms in the same way as normal
>> primates?
> If their mothers didn't have much body hair, it would mean that
> they would need to carry their babies the same way we do. Males
> could and probably did carry youngsters too. Have you ever gone
> hiking with your kids?
Your great weakness is that you never think in terms of
selective effects. If mothers needed a bit of hair to carry
their infants more effectively, they'd keep it. The ones that
didn't have hair (or maybe tufts of hair in the right places)
would do worse and would have fewer and less healthier,
children.
> So again I would say that it was not so much the use of these
> weapons that was significant, it was that they could imagine the
> use of a stick or rock for their own benefit. I think it was
> this understanding that was the big breakthrough.
Whenever you find yourself describing human evolution in terms
that you would never apply to other species, then you're
probably off the rails -- and certainly if the matter precedes
language.
> An evolutionary explanation based on climatic change is the
> first resort of a bad paleontologist (agreed there are an awful
> lot of them). Reduced resources just kill populations off.
> Why should dryer, colder conditions and an expansion of
> grasslands create more opportunities for a slow vulnerable
> hominid?
>
> I'm a little suspicious of anyone who would brand a
> paleontologist good or bad based on their views.
What criteria do you use? Their sex life? Paleontologists now
are in much the same situation as geologists were before 1967.
They don't have much opportunity to be good (except perhaps on
a technical level). So real bad thinking predominates and
numerous appalling theories are taken seriously.
> And there is ample evidence that climatic changes triggered
> dramatic changes in individual species.
No, there isn't. Most theories about the effects of climate
change are proved wrong within a few years -- as soon as better
data comes along.
> I prefer to think of the hominid as a generalist. From my
> point of view, our forebears liked to live in the seams between
> major habitat ecosystems. I think they were conmumate
> opportunists who liked to straddle the margins between land and
> sea, forest and plain.
We all prefer to think of our ancestors as the bee's knees.
It's a temptation to be avoided. Would you say this sort of
thing about other species? Are not foxes, racoons, bears,
crows and baboons, opportunists? Or even generalists? IMO
this is way of saying nothing. Is there a hypothesis here
that could be right or wrong? If so, how could it be proved
wrong?
>> > We must make a distinction between bipedalism that is seen in
>> > all primates that go wading (proboscis monkeys wade in mangrove
>> > forests but also walk & run bipedally on land, macaques on the
>> > beach, lowland gorillas in swamps, bonobos & other apes
>> > occasionally) & our present-day & rather recent long-legged &
>> > fully erect bipedalism.
>>
>> You left out the bipedalism exhibited by trained dogs or circus
>> animals. They have about the same relevance.
>>
>
> Again, I'm suspicious of smart alec remarks like this.
Hey, this is a newsgroup. If you say something stupid you are
liable to get a sharp answer. Those are the rules of the game.
So watch out.
> From my perspective, the significance of the other apes and
> monkeys that exhibit some bipedalism is that is demonstrates
> what may be partial adaptations. We see these all the time in
> the wild. There are iguanas in the Gallapagos who are paritally
> adapted to the marine environment. There are also cormorants
> there whose wings are useless for flying, but work fairly well
> as flippers. They are part way between the sea gulls and the
> penguins.
No, they are not part way between anything. Each species is
fully adapted to its niche. The phrase "partial adaptations" in
this context is an oxymoron.
>> I think that it's very important to have highly specific reasons
>> as to why the first hominids went bipedal (given the enormous
>> costs involved -- although I know you don't appreciate them).
>
> Again, why the snide remark?
Nothing snide. Marc specifically states that he doesn't think
bipedalism has major costs.
>> You're into promiscuous niche-swapping again. The evidence for
>> the "proneness to eat hard woody plants" is negligible. The
>> switch to such a diet by a frugivore animal is extremely
>> unlikely.
>
> Yet such a switch could become a necessity under the proper
> circumstances.
"Necessity" is meaningless in an evolutionary context. Billions
of populations of the millions of species go extinct every year.
All of them were under some "compulsion to change". They
couldn't. They died. What did "necessity" mean to them?
Paul.
Paul Crowley
>crow...@hotmail.com heeft geschreven in bericht
>>You need to decide whether the australopiths were bipedal or not.
>>Let me suggest some tests:
>>(a) Could males wield clubs and use stones as weapons?
> Even chimps brandish sticks, throw stones, crack nuts with
> stones, use twigs as probes... IMO australopiths did the same
> but no more.
"But no more" . . ? All our relatives have large canines. How
did the australopiths manage without them? Chimps flee danger
by running up trees, so they're not inclined to hold onto
weapons. If the australopiths lived in more open territory they
would not have had this option. They'd have had to stand still
in a group, using stones and clubs to keep the predators (or
enemy hominids) at bay.
>>(b) Could infants grip their mothers' hair (or sides) with the
>>feet and arms in the same way as normal primates?
>
> Probably. Sit on their mother's back as in chimps etc.
I'm sure you rode on your parent's back as a small child - but
it had to be horizontal. The adult has to be quadrupedal (or
"quadrupedal"). You can't possibly suggest that Lucy et al. were
quadrupedal like this.
>>(c) Could females with infants run, climb, fight and
>>defend themselses as well as normal primates?
>
> Probably. Why not? There is not very much human in
> australopiths. (You're still talking about australopiths, not
> about H.erectus, are you?)
Female primates (other than humans) carrying large infants
_never_ travel bipedally on the ground. They always go
quadrupedally. Are you saying australopiths were the same???
Did female australopiths with infants walk quadrupedally??
Female apes and monkeys almost always have four free limbs.
So they can climb, run, fight, forage and so on. How many free
limbs did female australopiths-with-infants have?
>>Their hands seem to me to be almost human. They certainly had
>>opposable thumbs. They had just lost their large canines so
>>they must have acquired other weapons --
>
> Why "must"? Herbivores like horses or capibaras or beavers
> don't have "large canines or other weapons".
All animals such as horses, capybaras and beavers have their own
perticular ways of dealing with predators -- such as speed,
large sharp teeth or heavy claws. Hominids had none of these.
Most primates have large canines. The australopiths lost theirs.
This *must* mean that they no longer needed them, which *must*
mean that they had some other defence. Since they now had hands
capable of wielding weapons (and since we know that hominids
developed this practice at some point) there is IMO no other
possibility.
>>Once a animal starts to use hand-held weapons it is effectively
>>impossible that it cease their use, and then re-grow large canines.
>
> Why do you think so?
Because clubs and stones are much more effective weapons than
large canines. They can suffer great damage without harm to
the hominid. They are readily replaceable. They don't need
large amounts of supporting bone and tissue. The loss of large
canines was a remarkable development. I think the reasons are
obvious and only an allegiance to the theory that australopiths
are the ancestors of apes prevents you seeing them. It is up to
you to come up with your own reasons for your proposed loss and
re-acquisition of large canines.
>>reasons for the longer legs and larger brains of the homo line
>>should not be too hard to see.
>
> Why do you think so?
Longer legs and the bipedal stride are much more efficient. The
main question is why they didn't come earlier. I have suggested
that the australopiths may have needed to chimney up more-or-
less vertical tree trunks, thereby needing short legs and long
arms; and that the Homo line learned to use bindings -- putting
a band around their ankles, enabling them to chimney in the same
way as humans, so they were no longer restricted to the old
morphology. Regrettably this is not a testable theory. But it
could easily have been some cultural development of this nature.
>>Having a group of quasi-chimps start relying on a diet with
>>large proportion of shellfish and stop sleeping in trees would
>>be a major part of niche change.
>
> Isn't that what you call niche-swapping? All in one step is too
> much.
There had to be at least one niche-swap between the quasi-chimp
and hominids. It is parsimonious to keep them to the smallest
possible number.
I think the only reason you want to say that one niche-change
would involve too much, is that it is an unfamiliar idea. If
we put _anything_ (any one of nakedness, loss of the sense of
smell, tool-using, sweating, bipedalism, fixed sites, burial of
dead, use of dogs, altriciality, subcutaneous fat, infant fat,
high water needs, high salt needs, etc.) to a later stage then
we have an entire niche-swap to explain.
> (What I said was just a possibility: a gradual change from
> shells to hard nuts or vice versa - mangrove capuchins eat both.
> I don't understand what you have with "niche-swapping".)
Then you are not sensitive to the concept of niche. Blue tits.
coal tits, great tits, long-tailed tits, etc., occupy related
niches but have kept their identity for millions of generations.
They do not drift from one type of food to another. I accept
that such drift can happen among small isolated populations in
highly restricted ecologies (such the Darwin's finches you
mention) but it rarely occurs on continents. While many
Marc Verhaegen
Paul Crowley heeft geschreven in bericht
<356773dc...@news.indigo.ie>...
>On Fri, 22 May 1998 19:19:55 +0200, "Marc Verhaegen"
><Marc.Ve...@village.uunet.be> wrote:
>
>>crow...@hotmail.com heeft geschreven in bericht
>>>You need to decide whether the australopiths were bipedal or not.
>
>>>Let me suggest some tests:
>>>(a) Could males wield clubs and use stones as weapons?
>
>> Even chimps brandish sticks, throw stones, crack nuts with
>> stones, use twigs as probes... IMO australopiths did the same
>> but no more.
>
>"But no more" . . ? All our relatives have large canines.
Most australoptihs had short canines. Bonobos have +- short canines. See
below.
> How
>did the australopiths manage without them? Chimps flee danger
>by running up trees, so they're not inclined to hold onto
>weapons. If the australopiths lived in more open territory they
>would not have had this option.
Early & gracile australopiths lived in forested areas, esp. gallery woods...
Robusts lived in more open landscapes, not withouth trees, in marshlands...
Apes need their large canines for opening fruits... The males also for
intraspecific use.
Australopiths had a more herbivorous, less frugivorous diet than most
present-day apes, so long canines were a handicap.
> They'd have had to stand still
>in a group, using stones and clubs to keep the predators (or
>enemy hominids) at bay.
Rather improbable for Austr. (You're perhaps describing H.erectus?)
Leopards were the most dangerous. The smaller austr. could flee into the
trees or into the water, but perhaps the larger ones (some males almost as
big as gorillas) could use clubs, as chimps sometimes do.
>
>>>(b) Could infants grip their mothers' hair (or sides) with the
>>>feet and arms in the same way as normal primates?
>>
>> Probably. Sit on their mother's back as in chimps etc.
>
>I'm sure you rode on your parent's back as a small child - but
>it had to be horizontal. The adult has to be quadrupedal (or
>"quadrupedal"). You can't possibly suggest that Lucy et al. were
>quadrupedal like this.
You must compare Lucy's locomotion to that of proboscis monkeys, somewhat
less arboreal, somewhat more bipedal wading & swimming. I don't see problems
for her children, they could grasp her hairs.
>
>>>(c) Could females with infants run, climb, fight and
>>>defend themselses as well as normal primates?
>>
>> Probably. Why not? There is not very much human in
>> australopiths. (You're still talking about australopiths, not
>> about H.erectus, are you?)
>
>Female primates (other than humans) carrying large infants
>_never_ travel bipedally on the ground. They always go
>quadrupedally. Are you saying australopiths were the same???
>Did female australopiths with infants walk quadrupedally??
(There is no "primate locomotion". Primates are very diverse.)
Large infants could run or walk or, if necessary, easily sit on their
mother's back, whether she was bi-, tri- or quadrupedal. Difficult to say
which carrying position was commonest for the small infants, but there were
a lot of possibilites. Australopiths had a unique lifestyle (studies of CE
Oxnard). Chimp mothers with small infants often walk on three legs, holding
the baby with one arm. They did not have to travel far. Just a few
(deci)metres to get the next food item. I think you have to see more
wildlife films of apes.
>>>They had just lost their large canines so
>>>they must have acquired other weapons --
>>
>> Why "must"? Herbivores like horses or capibaras or beavers
>> don't have "large canines or other weapons".
>
>All animals such as horses, capybaras and beavers have their own
>perticular ways of dealing with predators -- such as speed,
>large sharp teeth or heavy claws. Hominids had none of these.
(Hominids are: australopiths, chimps, gorillas, humans - see molec.data &
see below.
If you mean fossil hominids, try to specify: australopiths or fossil Homo -
big difference.)
Both australopiths & extinct Homo lived at the edge between land & water. If
the danger came from the land, they fleed to the water (or trees in the case
of the australopiths), etc. Homo probably used stones or clubs,
australopiths rarely.
>Most primates have large canines. The australopiths lost theirs.
>This *must* mean that they no longer needed them, which *must*
>mean that they had some other defence. Since they now had hands
>capable of wielding weapons (and since we know that hominids
>developed this practice at some point) there is IMO no other
>possibility.
See above.
Australopiths (group animal) escaped predators +- like tapirs or capybaras
or proboscis monkeys do: running to the land or to the water or to the
trees, according to where the danger comes from. The biggest problem is
spotting the enemy before he's too near.
>>>Once a animal starts to use hand-held weapons it is effectively
>>>impossible that it cease their use, and then re-grow large canines.
>>
>> Why do you think so?
>
>Because clubs and stones are much more effective weapons than
>large canines. They can suffer great damage without harm to
>the hominid. They are readily replaceable. They don't need
>large amounts of supporting bone and tissue.
(Stones & clubs must be carried. Apes & monkeys can handle clubs, but prefer
not to use them frequently.)
>The loss of large canines was a remarkable development.
Not for herbivores! We see a relative canine reduction from graciles to
robusts, just as expected from their diet. I can't see any problem for
explaining the australopith canines.
As for Homo, in Mojokerto"in front of the upper canine there is a gap of 6
mm into which no doubt a much more powerful canine (more like that of an
anthropoid ape) could fit" (p.36 B.Rensch 1972 Homo sapiens. Columbia UP),
but other erectus had smaller canines.
> I think the reasons are
>obvious and only an allegiance to the theory that australopiths
>are the ancestors of apes prevents you seeing them.
I can't see anything typically human in australopiths, see my papers:
1990. African ape ancestry. Human Evolution 5, 295-297.
1994. Australopithecines: ancestors of the African apes? HE 9, 121-139.
1996. Morphological distance between australopithecine, human and ape
skulls. HE11, 35-41.
Australopithecine ancestors of African apes?
Palaeo-anthropological data do not exclude the possibility that chimpanzees
and gorillas could have had australopithecine-like ancestors. In fact, the
traditional hypothesis – that all australopithecines are closer relatives of
humans than of chimps or gorillas – has serious difficulties:
a. The apparent absence or extreme rarity of fossil ancestors or relatives
of any African ape is puzzling (fossils of orangs & all sorts of monkeys
have been found, but fossil-hunters, understandably, prefer to see the
"human" features (IMO=common hominid featrues) in the australopiths they
find rather than the much more numerous chimp or gorilla features)
b. Various australopith-like features are present in premature but not in
adult African apes (e.g. relative orthognathy, less dorsal foramen magnum,
more orthogrady).
c. Australopiths lack the uniquely derived features that set Homo, at least
since erectus, apart from nonhuman primates (e.g. external nose, very large
brain, very long legs)
d. Australopiths generally resemble the apes much more than they do humans.
e. At the time of the robust australopiths there already lived more
humanlike creatures like KNM-ER 1470, so the robusts at least are certainly
not in our ancestry.
The Laetoli footprints A and G suggest that australopithecines were partly
or fully bipedal. Bipedalism is generally considered to be the defining
feature of the hominids, which links australopiths with humans. But the
African apes’ locomotion is unique - plantigrady plus knuckle-walking - and
is easily derivable from some kind of “short”-legged plantigrade bipedalism
as is frequently seen in lowland gorillas wading in shallow waters and
occasionally in all African apes. If the African apes had more bipedal
ancestors, there is every reason to include them into the hominids – in
agreement with the comparative molecular evidence of DNA and proteins.
> It is up to
>you to come up with your own reasons for your proposed loss and
>re-acquisition of large canines.
No loss & re-acquisition (eg, oscilations of larger & smaller beaks in
Galàpagos finches according to the wetness or dryness of the previous
seasons), but strong overlap between apes/australopiths/Homo:
- afarensis & africanus had moderately projecting canines, but the robusts
were more herbivorous, hence shorter canines
- even in robusts SK-23, Natron, L-7-125 the mandible form (rectangle) is
within the common chimp range, outside the human range (WG Kinzey 1970
Nat.228:289)
- in gorillas & chimps "with advancing age, canines thend to wear flat to
the level of the incisors" & bonbos "have rel.smal & only slightly
projecting canine teeth"
- Mojokerto Homo erectus had maxill.diastemata as large as an orang's (see
above), much larger than in most australopiths
- selection for larger & smaller teeth can occur in very short evol.periods
(R.Silson 1988 Additive genes in selection & evolution. Greenfield Publ.
Tring, see also Calcagno & Gibson 1988 AJPA 77:505, and Darwin's finches)
>>>reasons for the longer legs and larger brains of the homo line
>>>should not be too hard to see.
>>
>> Why do you think so?
>
>Longer legs and the bipedal stride are much more efficient.
>The main question is why they didn't come earlier.
Yes, even babies still have rel.short legs. For walking & wading (beach,
rivers...), long legs might be advantageous (stork...), but for swimming &
diving shorter legs are better.
>>>Having a group of quasi-chimps start relying on a diet with
>>>large proportion of shellfish and stop sleeping in trees would
>>>be a major part of niche change.
>>
>> Isn't that what you call niche-swapping? All in one step is too much.
>
>There had to be at least one niche-swap between the quasi-chimp and
hominids.
No swap but shift.
>It is parsimonious to keep them to the smallest possible number.
Evolution is gradual: no niche-swapping, but diet-overlapping & gradual
shift.
The last common ancestor chimp+human already waded in
forest/gallery/mangrove swamps & ate herbs, fruits, nuts, cane, perhaps
already shellfish. The ape ancestors went inland (=australopiths) & became
more herbivorous, human ancestors went to the coasts & developed their
shell-processing (stone, later tool use) & diving abilities (eg, E.Schagatay
1996 The human diving response - effects of temperature & training.
Univ.Lund)
Simple, isn't it? No niche-swapping at all.
>I think the only reason you want to say that one niche-change
>would involve too much, is that it is an unfamiliar idea. If
>we put _anything_ (any one of nakedness, loss of the sense of
>smell, tool-using, sweating, bipedalism, fixed sites, burial of
>dead, use of dogs, altriciality, subcutaneous fat, infant fat,
>high water needs, high salt needs, etc.) to a later stage then
>we have an entire niche-swap to explain.
???
More shellfish-eating > more naked & SC fat & stone use.
Human long-legged bipedalism is more recent. See above.
Burial?? dogs??
>> (What I said was just a possibility: a gradual change from
>> shells to hard nuts or vice versa - mangrove capuchins eat both.
>> I don't understand what you have with "niche-swapping".)
>
>Then you are not sensitive to the concept of niche. Blue tits.
>coal tits, great tits, long-tailed tits, etc., occupy related
>niches but have kept their identity for millions of generations.
Not millions (is it 10 mya that they all split apart??).
Evolution exists, you know. It's usu. slow (oscillating = slow on the long
run), but when the environment changes (island colonisation, climatic
changes...) it can be "very fast".
>They do not drift from one type of food to another. I accept
>that such drift can happen among small isolated populations in
>highly restricted ecologies (such the Darwin's finches you
>mention) but it rarely occurs on continents.
What is "drift"?
See, eg, the parallel evolutionary "shifts" in the suids of White & Harris'
(1977 Sci.198:13).
Marc
Marc Verhaegen
Paul Crowley heeft geschreven in bericht
<356771e4...@news.indigo.ie>...
>On Thu, 21 May 1998 19:45:20 -0700, "Norman K. McPhail"
><no...@socal.wanet.com> wrote:
>Whenever you find yourself describing human evolution in terms
>that you would never apply to other species, then you're
>probably off the rails -- and certainly if the matter precedes
>language.
Beautifully said!
(On what has been said above I mostly agree with Norman.)
...
>Marc specifically states that he doesn't think bipedalism has major costs.
???
I said that (short-legged) bipedalism is not such a great step for an
arboreal mammal that lives at the edge between land & water.
Marc
Gerrit Hanenburg
Marc Verhaegen <Marc.Ve...@village.uunet.be> wrote:
>I can't see anything typically human in australopiths,
Then again, does Verhaegen know anything about the details of
australopithecine anatomy?
Synapomorphies of Australopithecus and Homo:
Five or six (Sts 14 and KNM-WT 15000) lumbar vertebrae.
Lumbar lordosis and sacral retroflexion.
Sacral ala laterally expanded.
Sacroiliac and hip joints closely approximated.
Pelvis with: mediolaterally expanded, superioinferiorly shortened, and
anteriorly rotated iliac blades; robust anterior iliac spines;
distinct sciatic notch; distinct iliopsoas grove; rugose and large
area for sacrotuberous ligament; retroflexed auricular surface with
extensive retroarticular area; robust posterior superior iliac spine;
sigmoid curvature of the iliac crest; dorsoventrally thickened pubic
symphysis; retroflexion of hamstring tuberosity; shortened iliac
shank.
Femoral neck long with human-like distribution of cortical and spongy
bone.
Distal femur with: high bicondylar angle, elliptical lateral condyle,
deep patellar groove with high lateral lip.
Tibia with straight shaft and distal articular surface perpendicular
to the shaft axis.
Calcaneus with: massive body, deep dorsoplantar dimension, ovoid
transverse section, horizontally oriented sustentacular shelf.
Proximal phalanges of the foot with dorsally oriented proximal
articular surfaces.
Metatarsals II-V with heads expanded superiorly.
Robust metatarsal V with large tuberosity.
Metatarsal I with robust triangular diaphysis and expanded head.
Univertebral articular pattern for the first rib.
Proximal humerus with shallow bicipital groove.
Distal humerus with: rounded lateral well of the olecranon fossa;
gracile lateral epicondyle; moderate-sized and cranially facing medial
epicondyle.
Radiocarpal joint perpendicular to the shaft axis.
Capitate with: proximodistally shortened axis; single and elongated
facet for MC II; shallow excavations for MC III articulations.
Metacarpals II-V relatively short.
(McHenry 1991, 1994)
Reduced canines and incisors.
Tooth enamel thick.
Foramen magnum positioned at or anterior to the bi-tympanic line.
And in the case of robust australopithecines add:
Pars petrosa ossis temporalis coronally oriented.
Flexed cranial base.
Vertically oriented mandibular symphysis.
Refs:
McHenry, H.M. 1991. First Steps? Analysis of the Postcranium of Early
Hominids. In Coppens, Y. and Senut, B.(eds) 1991. Origine(s) de la
Bipedie chez les Hominides. Paris: CNRS. pp. 133-141.
McHenry, H.M. 1994. Early Hominid Postcrania: Phylogeny and Function.
In Corrucini, R.S. and Ciochon, R.L.(eds) 1994. Integrative Paths to
the Past. Englewood Cliffs, NJ: Prentice Hall. pp.251-268.
Gerrit.
Norman K. McPhail
> ><no...@socal.wanet.com> wrote:
>
> >Whenever you find yourself describing human evolution in terms
> >that you would never apply to other species, then you're
> >probably off the rails -- and certainly if the matter precedes
> >language.
>
> (On what has been said above I mostly agree with Norman.)
I find the "off the rails" metaphor typical of the mind set of most
scientists. It generally works well in the realms of physics and
biology. But as we begin to try to fathom how and why symbolic thought
self-organized, I think this "either/or" logic causes a big blind spot.
I recognize that that there were both genetic and instinctual components
involved in how and why we got to be ther way we are. So it is not
absolutely wrong to point out that deterministic selection was involved.
Yet I can't ignore the fact that somehow our forebears found a way to
change their gene changing problems into thought problems.
So my hypothesis is that the big breakthrough was our forebears'
understanding, however vague and gradual, that sticks and stones could
replace their lack of speed, claws, fangs and other waapons. And I
claim that this was at least as much of an insight as it was what we
might say was an instinctual or genetic change.
In my view, try as they may, scientists won't crack the secrets of the
emergence of thought until they change some of their basic assumptions
and thought modes. And if they want to lock themselves into a
deterministic reductionistic box, that's their business. I'm not here
on a mission to teach. And the last thing I want to do is to try to
convert some crusty scientist. My assumption is that I would never
succeed anyway.
On the other hand, I respect your opinions and find that your views and
explanations are well balanced and insightful. (For a scientist #:) So
I'm here mainly to learn from you.
This brings me to your comments on the brain size/birth canal question.
So I'll switch over to the other thread.
Norm
Marc Verhaegen
Gerrit Hanenburg heeft geschreven in bericht
<35681654...@news.kijfhoek.nl.net>...
>Marc Verhaegen <Marc.Ve...@village.uunet.be> wrote:
>
>>I can't see anything typically human in australopiths,
Typically human is what makes humans unique. The very large brain, the
external nose, the very long legs are completely absent in all
australopiths. It's true that australopiths had a more orthograde locomotion
(foramen magnum position, lumbar lordosis & related features), but it has
been repeated argued that some sort of bipedality (IMO wading) is the
ancestral condition of all hominids (=Afr.hominoids) (eg, Coon 1954,
Kleindienst 1975, Goodman 1982, Gribbin & Cherfas 1983, Hasegawa etc. 1985,
Edelstein 1987, my work see esp. "Australop.:ancestors of the Afr.apes"
Hum.Evol.9:121-139, 1994).
>Then again, does Verhaegen know anything about the details of
>australopithecine anatomy?
Then again, is Hanenburg always so biased in his data?
Why does he omit the even more numerous apelike features in the
australopiths??
We know of course McHenry's list.
It looks more impressive than it is. Just see Stern & Susman's famous paper:
JT Stern & RL Susman 1983 The locomotor anatomy of A.afarensis.
Am.J.phys.Anthrop.60:279-317
Most of the listed features can be grouped in functionally related
adaptations.
For instance, the broad pelvis (unlike humans & apes) with the laterally
expanded alae, the long femoral necks, high bicondylar angle are - together
with the apelike small femoral heads & short femoral shafts - are the
expressions of the same adaptation: better abduction of the thighs (is seen
in some swimming mammals & seems to suggest that the australopiths not only
waded bipedally but also frequently swam - the same is true for the
australopith feet). These are certainly not adaptations for humanlike
bipedality: in that case the pelvis should have been narrower, the femoral
heads much larger, etc.
For a functional discussion of most of these anatomical features see my
work, eg,
1987. Vertonen de fossiele hominiden tekens van wateraanpassing? Marswin 8,
142-151.
1991. Aquatic ape theory and fossil hominids. Medical Hypotheses 35,
108-114.
1991. Aquatic features in fossil hominids? M. Roede ed. The Aquatic Ape:
Fact or Fiction? Souvenir, London, 75-112.
1997. In den Beginne was het Water. Nieuwste Inzichten in de Evolutie van de
Mens. Hadewijch, Antwerpen.
McHenry's list consists merely of 2 groups: primitive features of all
hominoids or hominids (sometimes more monkeylike), and typically
australopithecine features such as the very broad pelvises (broader than in
humans & apes).
Australopiths display a mosaic of monkeylike, apelike & humanlike features,
as could be expected in creatures that lived a few million years earlier
than humans & apes.
Most of the enumerated features are related to the locomotion & the
dentition, & all features perfectly fit my view of the australopithecines as
wading herbivores. See my previous messages to s.a.p.
This, as I repeatedly argued, is the ancestral condition for all hominids.
(hominids=African hominoids: australopithecines, gorillas, chimpanzees,
humans).
As both humans & African apes descend from more australopith ancestors, it's
only natural that many humanlike (though less than apelike) features can be
seen in the australopiths.
>Synapomorphies of Australopithecus and Homo:
Or what is traditionally called synapomorphies, if it's assumed that apes
represent the ancestral state. This of course is not true. Apes are highly
derived in many features, eg, the low number of vertebrae, the very long
ilia, the very long arms etc. are more derived than in humans &
australopiths. This has no meaning as for the relatedness of humans &
australopiths: both just display in these features the ancestral hominid or
hominoid situation (eg, number of vertebrae: +-7 in monkeys, +-5 in
australoptihs & humans, +-3 in apes).
>Five or six (Sts 14 and KNM-WT 15000) lumbar vertebrae.
>Lumbar lordosis and sacral retroflexion.
>Sacral ala laterally expanded.
>Sacroiliac and hip joints closely approximated.
>Pelvis with: mediolaterally expanded, superioinferiorly shortened, and
>anteriorly rotated iliac blades; robust anterior iliac spines;
>distinct sciatic notch; distinct iliopsoas grove; rugose and large
>area for sacrotuberous ligament; retroflexed auricular surface with
>extensive retroarticular area; robust posterior superior iliac spine;
>sigmoid curvature of the iliac crest; dorsoventrally thickened pubic
>symphysis; retroflexion of hamstring tuberosity; shortened iliac
>shank.
>Femoral neck long with human-like distribution of cortical and spongy
>bone.
>Distal femur with: high bicondylar angle, elliptical lateral condyle,
>deep patellar groove with high lateral lip.
Discussion of pelvis & thighs see above.
Related with bipedalism & perhaps swimming (thigh abduction, broad pelvis,
lumbar lordosis, see discussion in Verhaegen 1991, 1997)
>Tibia with straight shaft and distal articular surface perpendicular
>to the shaft axis.
>Calcaneus with: massive body, deep dorsoplantar dimension, ovoid
>transverse section, horizontally oriented sustentacular shelf.
>Proximal phalanges of the foot with dorsally oriented proximal
>articular surfaces.
>Metatarsals II-V with heads expanded superiorly.
>Robust metatarsal V with large tuberosity.
>Metatarsal I with robust triangular diaphysis and expanded head.
Flipperlike (long metatarsals & short digits) = swimming feet:
in sealions > humans > australopiths > Afr.apes
See discussion & figs.5.4 & 5.5 in Verhaegen 1991 &
figure in Verhaegen 1993 "Aquatic vs savanna..." Nutr.Health 9:165-191
Full plantigrady is seen, eg, in humans & Afr.apes & australopiths &
sealions.
>Univertebral articular pattern for the first rib.
Instead of bivert.articulation. Chimps are intermediary.
Discussed in Verhaegen 1991
(loose rib articulations are seen in most aquatic mammals)
>Proximal humerus with shallow bicipital groove.
>Distal humerus with: rounded lateral well of the olecranon fossa;
>gracile lateral epicondyle; moderate-sized and cranially facing medial
>epicondyle.
>Radiocarpal joint perpendicular to the shaft axis.
>Capitate with: proximodistally shortened axis; single and elongated
>facet for MC II; shallow excavations for MC III articulations.
>Metacarpals II-V relatively short.
>(McHenry 1991, 1994)
Primitive arm in australopiths, not yet knuckle-walking.
(first K-W features are seen in boisei arm bones)
Shoulder girdle very chimp-like, derived.
>Reduced canines and incisors.
>Tooth enamel thick.
Ancestral condition probably (Martin 1985)
>Foramen magnum positioned at or anterior to the bi-tympanic line.
More anterior for.magnum in bonobos & all premature apes.
>And in the case of robust australopithecines add:
>Pars petrosa ossis temporalis coronally oriented.
>Flexed cranial base.
>Vertically oriented mandibular symphysis.
Parallel adaptations: robusts lived at the same time as Homo!
>
>Refs:
>
>McHenry, H.M. 1991. First Steps? Analysis of the Postcranium of Early
>Hominids. In Coppens, Y. and Senut, B.(eds) 1991. Origine(s) de la
>Bipedie chez les Hominides. Paris: CNRS. pp. 133-141.
>
>McHenry, H.M. 1994. Early Hominid Postcrania: Phylogeny and Function.
>In Corrucini, R.S. and Ciochon, R.L.(eds) 1994. Integrative Paths to
>the Past. Englewood Cliffs, NJ: Prentice Hall. pp.251-268.
From my 1994 paper:
As we go further back in time, we may expect that human ancestors become
more chimpanzeelike, but also that the chimpanzees' ancestors become more
humanlike, ie, display a few humanlike features. Assuming that the LCA (last
common ancestor) looked much more like a chimp is statistically less likely
than assuming that the LCA already possessed a few mosaic humanlike features
(eg, facultative bipedality, orthognathism, thicker enamel) & that both
branches (Homo & Pan) underwent evol.changes towards their present-day
representants (eg, much longer legs in humans, longer arms in chimps). In
fact, it seems most economical to assume that the LCA 8-4 mya looked
somewhat like bonobos (or like subadult chimps), which are in several
instances - but not, eg, in body weight - intermediate between humans &
common chimps, eg, in rel.canine size, canine dimorphism, orthognathism,
foramen magnum indices, rel.arm & leg length, bipedalism & knuckle-walking.
Although the LCA lived earlier, the gracile australopiths of 3-2.5 mya
(Lucy, Sterkfontein) are the best approximation we presently have...
It seems that, while our ancestors were becoming more & more humanlike, the
Afr.apes - at first the ancestors of the gorillas & shortly thereafter that
of both chimpanzees - for unknown reasons (climatic & habitat changes?)
broke away from our evol.direction, partially reversed their evolution, &
became again - the 3 species to different degrees - more like monkeys in
thinner enamel, larger front teeth, prognathism, ectocranial crests,
rel.smaller endocast, more dorsal foramen magnum, elongated iliac blades,
short femoral necks, less valgus knees, more grasping feet, quadrupedalism
etc. (but not, eg, in body size, relative arm length, knuckle-walking,
pelvic height, number of lumbar, sacral & coccygal vertebrae).
There are admittedly several weak spots in the scenario: the many reversals
(notably in the lower limb anatomy) & parallelisms (eg, anterior dentition,
iliac anatomy, knuckle-walking adaptations) in the evolution of Gorilla &
Pan. (If Pongo is included in the comparison, even more - apparently
improbable - parallelisms are needed, although, as discussed above, for most
of these featues (eg, sexual dimorphism, foramen magnum position, rel.arm
length, foot shape), at least one Afr.ape species can be found to be more
different from orangs than from humans, & Andrews (1992), in a review of
Miocene hominoids, even asserts that "if Sivapith. belongs in the orangutan
clade, as I have argued, the shared [postcranial] morphology of the
orangutan & the Afr.apes must have arisen independently").
However, if these reversals & parallelisms are correlated (readaptations to,
eg, an older, less "innovating or less humanlike lifestyle or environment),
the counter-argument to my scenario fails. Moreover - the traditional
hypothesis - that all australopithecines are more closely related to humans
than to Afr.apes - seems to have more serious difficulties:...(see previous
messages to s.a.p: "absence" of fossil chimps & gorillas; australopith
features in premature apes (orthognath., for.magnum position, more humanlke
feet); absence of ext.nose, very large brain, very long legs in austral.;
general resemblance with apes; contemporanity of Austr. & Homo).
Conclusion
A review of the paleo-anthrop.literature reveals no data that exclude the
possibility that both gorillas & chimps could have had austral.ancestors.
Bipedalism is generally considered to be the shared features that links
austral. with humans, & there is no doubt that at least some of the austral.
species were partial bipeds. But it has never been proven that the Afr.apes'
unique locomotion (plantigrady & knuckle-walking) could not have evolved
from some kind of "short"-legged bipedalism. In fact... ontogenetic &
morphological evidence tends to favour the hypothesis that the LCA of Homo &
Pan 8-4 mya was a partially bipedal, gracile australopith, with chiefly a
mosaic of human & chimp (esp. bonobo) features: low sexual dimorphism,
minimal prognathism, slightly enlarged canines, non-protruding nasal
skeleton, smooth ectocranium without crests, "small" brain with apelike
sulcal pattern, re.non-flexed basicranium, intermediate position of
for.magnum, "short" forelimbs without knuckle-walking features, low ilia,
(very) long femoral necks, "short" legs, (very) valgus knees, full
plantigrady, longer & not very abductable halluces...
Gerrit Hanenburg
Marc Verhaegen <Marc.Ve...@village.uunet.be> wrote:
>Then again, is Hanenburg always so biased in his data?
>Why does he omit the even more numerous apelike features in the
>australopiths??
Because the issue was "I can't see anything typically human in
australopiths", remember?
>Most of the listed features can be grouped in functionally related
>adaptations.
>For instance, the broad pelvis (unlike humans & apes) with the laterally
>expanded alae, the long femoral necks, high bicondylar angle are - together
>with the apelike small femoral heads & short femoral shafts - are the
>expressions of the same adaptation: better abduction of the thighs (is seen
>in some swimming mammals & seems to suggest that the australopiths not only
>waded bipedally but also frequently swam - the same is true for the
>australopith feet). These are certainly not adaptations for humanlike
>bipedality: in that case the pelvis should have been narrower, the femoral
>heads much larger, etc.
These features function as a lateral balancing system. If you want
better abduction of the thigh you need something similar to Pongo
(shallow acetabulum, etc.)
There is no better explanation than that these features functioned in
balancing the torso over the hips during bipedalism.
There's no indication whatsoever that these features are aquatic
adaptations (though they do not prohibit wading).
Most mammals that enter the water use a modified form of terrestrial
gait (i.e. parasaggital paddling), without abduction of the thigh.
(Thewissen, J.G.M. & Fish, F.E.1997. Locomotor evolution in the
earliest cetaceans: functional model, modern analogues, and
paleontological evidence. Paleobiology 23: 482-490)
>>Synapomorphies of Australopithecus and Homo:
>Or what is traditionally called synapomorphies, if it's assumed that apes
>represent the ancestral state. This of course is not true.
Then, what method do you use to polarize the characters?
On the basis of outgroup comparison there's little doubt that large
projecting canines are plesiomorphic, as are small brains, long arms,
long ilia, absence of lumbar lordosis, etc.
>Flipperlike (long metatarsals & short digits) = swimming feet:
>in sealions > humans > australopiths > Afr.apes
Metatarsals and phalanges in humans and australopithecines relatively
shorter than in non-aquatic Afr.apes.
>Full plantigrady is seen, eg, in humans & Afr.apes & australopiths &
>sealions.
Yes, plantigrady was probably already present in the bear-like
terrestrial ancestor of Pinnipedimorpha and has nothing to do with
aquaticness.
>Univertebral articular pattern for the first rib.
>Instead of bivert.articulation. Chimps are intermediary.
>Discussed in Verhaegen 1991
>(loose rib articulations are seen in most aquatic mammals)
Whales have single-headed ribs, but this situation is not even
remotely present in hominins.
>Primitive arm in australopiths, not yet knuckle-walking.
>(first K-W features are seen in boisei arm bones)
And those incipient K-W features are?
>Shoulder girdle very chimp-like, derived.
With cranially oriented glenoid fossa?
>>Reduced canines and incisors.
>>Tooth enamel thick.
>Ancestral condition probably (Martin 1985)
Unlikely now that we know that the most basal hominin Ardipithecus
ramidus had also thin enamel.
>>And in the case of robust australopithecines add:
>>Pars petrosa ossis temporalis coronally oriented.
>>Flexed cranial base.
>>Vertically oriented mandibular symphysis.
>Parallel adaptations: robusts lived at the same time as Homo!
Contemporaneous existence of taxa is not a criterium for parallelism.
Parallelism is found when a character is derived more than once in a
cladogram.
The above features could have been present in the LCA of
Homo+Paranthropus (Skelton, R.L.& McHenry, H.M. 1992. Evolutionary
relationships among early hominids. J.of Human Evol. 23: 309-349)
Gerrit
Paul Crowley
>Most australoptihs had short canines.
All australopiths had small canines.
>Bonobos have +- short canines. See below.
I can find no confirmation of this. The difference with ordinary
chimps can only be slight.
>Early & gracile australopiths lived in forested areas, esp. gallery woods...
>Robusts lived in more open landscapes, not withouth trees, in marshlands...
You repeat this like a mantra. There is little or no good
evidence for this sort of thing. Hominids (normal definition)
could walk and their fossils may be found a long way from their
habitat, especially if their normal habitat was not suitable for
fossilization.
>Apes need their large canines for opening fruits... The males also for
>intraspecific use.
The opening fruit use for large canines is fairly minor. All
primates, other than us, have large canines. Many have little
dietary application (e.g. male gorillas or male gibbons). Their
use in discouraging predators, especially for males, is probably
their most important value.
>Australopiths had a more herbivorous, less frugivorous diet than most
>present-day apes, so long canines were a handicap.
Firstly, you've no real evidence for a more herbivorous diet.
Secondly, it would hardly be more herbivorous that of the gorilla
and they have very large canines. Thirdly, there is no clear way
that a animal with large canines could adapt to diet that
required a horizontal (cow-like) motion of the jaws. That motion
only becomes possible once the large canines have gone; so there
is no mechanism that could enable a gradual reduction.
Fourthly, once an animal had adapted to such a diet, there is no
way that large canines could come back (as you assert vis-a-vis
gorillas). Fifthly, you can point to no parallels among any
other large-bodied (or even small-bodied) mammalian taxa of such
rapid changes in diet and morphology.
>> They'd have had to stand still
>>in a group, using stones and clubs to keep the predators (or
>>enemy hominids) at bay.
>
>Rather improbable for Austr. (You're perhaps describing H.erectus?)
Why improbable for the australopiths? Chimps are nearly there;
it is not IMO at all hard to see a chimp population that moved to
more open ground adopting such habits.
>Leopards were the most dangerous. The smaller austr. could flee into the
>trees or into the water,
The water would almost invariably have crocodiles. And leopards
do the predation on baboons in_the_trees at at night.
Australopiths in trees would be much more vulnerable than
baboons.
>You must compare Lucy's locomotion to that of proboscis monkeys, somewhat
>less arboreal, somewhat more bipedal wading & swimming. I don't see problems
>for her children, they could grasp her hairs.
At some point hominid females went fully bipedal. At some point
hominid infants stopped hanging on like other primate infants.
Until you've sorted out exactly how both happened, you've got
nowhere in human evolution.
>(There is no "primate locomotion". Primates are very diverse.)
The is a near-universal one for infants -- on their mother's
bellies or, occasionally, their backs.
>Large infants could run or walk or, if necessary, easily sit on their
>mother's back, whether she was bi-, tri- or quadrupedal.
How can an infant sit on a vertical back? It could sit on the
adult's shoulders, but I don't think anyone would claim that that
was a normal system.
>Difficult to say which carrying position was commonest for the
>small infants, but there were a lot of possibilites.
>Australopiths had a unique lifestyle (studies of CE
>Oxnard).
All species have a unique lifestyle. Your claim that it was
"more unique" has no real evidence. However there are only two
ways that primate mothers have solved the infant-carrying problem
(a) the human one -- for most of the time they leave it down and
(b) all other primates -- they carry it around for every minute
of every day, which is possible because it sticks like a bug.
>Chimp mothers with small infants often walk on three
>legs, holding the baby with one arm.
This is correct for new-borns or sick infants; but it is not the
normal system. Chimps mothers need both hands free to climb,
run, forage or protect themselves.
>They did not have to travel far. Just a few (deci)metres to get
>the next food item.
This is nonsense (if imaginative nonsense). What other large
animals (let alone primates) are in this fortunate position?
Perhaps the sloth. While the australopiths were clearly not
great at getting around, there would have been some selection for
travelling capacity. You can't hypothesize a "sloth-niche"
simply to suit an argument.
>I think you have to see more wildlife films of apes.
I record loads and study them carefully. (There's progamme on
proboscis monkeys on BBC2 tomorrow (Wednesday 27th 14:45) if you
get that channel).
>(Hominids are: australopiths, chimps, gorillas, humans - see molec.data &
>see below.
If you are going to define common words in your own peculiar way,
no one will have any idea what you are talking about.
>Both australopiths & extinct Homo lived at the edge between land & water. If
>the danger came from the land, they fleed to the water (or trees in the case
>of the australopiths), etc. Homo probably used stones or clubs,
>australopiths rarely.
Large cats are not afraid of water; many can climb trees. Quite
apart from the baby-carrying problem, the australopiths would be
much slower at running, climbing, and probably swimming than
baboons. The problem of predation has to be taken seriously.
>Australopiths (group animal) escaped predators +- like tapirs or capybaras
>or proboscis monkeys do: running to the land or to the water or to the
>trees, according to where the danger comes from. The biggest problem is
>spotting the enemy before he's too near.
Spotting the enemy at a distance is only useful if you're faster
than him or have a close refuge. Australopiths would have been
impossibly slow (especially females with infants) and had few
refuges.
>(Stones & clubs must be carried. Apes & monkeys can handle clubs, but prefer
>not to use them frequently.)
I accept that stones and clubs must be carried. This would have
been a very important motivation for bipedalism. Although I
doubt if the australopiths travelled much. It could well have
been the development by the Homo line of a capacity to carry
things (like clubs, stones, food) by, say, using animal skins
that enabled them to travel more effectively. Only then would
they have acquired the longer legs and more efficient stride.
>>The loss of large canines was a remarkable development.
>
>Not for herbivores!
How does a animal with large canines switch to a herbivorous
diet? Can you show such a change elsewhere in nature? (The
answer here is "Of course, not.)
>We see a relative canine reduction from graciles to
>robusts, just as expected from their diet. I can't see any problem for
>explaining the australopith canines.
(a) Just another unique event in evolution which only happens in
the hominid (usual sense) line. (b) No possible way it could
happen (c) leaves no defence equipment.
>> It is up to
>>you to come up with your own reasons for your proposed loss and
>>re-acquisition of large canines.
>
>No loss & re-acquisition (eg, oscilations of larger & smaller beaks in
>Galāpagos finches according to the wetness or dryness of the previous
>seasons), but strong overlap between apes/australopiths/Homo:
Gradually expanding or reducing beak size is a very different
operation from losing a feature that has been universal among
primates for at least 60 Myr. Natural variation in beak size can
readily be observed in any birds. Natural selection can make the
average size larger or smaller. That is easy to see. But for
all primates (other than us) losing their large canines would be
like losing their legs. They would lose their whole defence
function. It would mean near-instant death. It just couldn't
happen.
>- in gorillas & chimps "with advancing age, canines thend to wear flat to
>the level of the incisors"
You show quotes. What is your source here? This is very much
contrary to my understanding. I strongly doubt if male canines
wear down. Old chimp males often lose them, but they are far too
large to be worn down to molar level.
>& bonbos "have rel.smal & only slightly projecting canine teeth"
What is your source for this? Does it apply to males?
>>It is parsimonious to keep them to the smallest possible number.
>
>Evolution is gradual: no niche-swapping, but diet-overlapping & gradual
>shift.
>Burial?? dogs??
These were argued here in some rather long threads.
>>Then you are not sensitive to the concept of niche. Blue tits.
>>coal tits, great tits, long-tailed tits, etc., occupy related
>>niches but have kept their identity for millions of generations.
>
>Not millions (is it 10 mya that they all split apart??).
A generation in those birds is unlikely to be more than 3 years
and I'd guess they've been apart getting on for 10 Myr. I've
seen dna analyses of warblers indicating about 5 Myr separations.
>Evolution exists, you know. It's usu. slow (oscillating = slow on the long
>run), but when the environment changes (island colonisation, climatic
>changes...) it can be "very fast".
Exactly. But you use the slow "drift" notion for all your niche-
changes. I get the impression that you see a population about
the former size of bonobos gradually shifting from a frugivous to
a herbivorous diet. That, in my view, is impossible. The
environment did not change that much. If there was a viable
frugivorous niche, it won't go away. The only way I see that is
possible, in the very tight timescale we are allowed, is for a
small isolated population to find a whole new way of life, and
change radically. This IS possible and has been known to happen
thousands of times (e.g. Darwin's finches, fruit flies on Hawaii,
cichlid fish in Lake Victoria). This new species will then
expand back to its parent species's territory and IF its_niche_
_overlaps_with its parent and IF it has major advantages, it may
wipe it out. Since both of these conditions are unlikely, the
parent species will normally continue to exist. But none of your
hypothetical parent species exist.
Paul.
Jim McGinn
Marc Verhaegen wrote in message <6k8msv$ep3$1...@xenon.inbe.net>...
>
>Paul Crowley heeft geschreven in bericht
><356771e4...@news.indigo.ie>...
>>On Thu, 21 May 1998 19:45:20 -0700, "Norman K. McPhail"
>><no...@socal.wanet.com> wrote:
>
>>Whenever you find yourself describing human evolution in terms
>>that you would never apply to other species, then you're
>>probably off the rails -- and certainly if the matter precedes
>>language.
>
>Beautifully said!
>(On what has been said above I mostly agree with Norman.)
>
>...
<snip>
This is simply wrong. If anything is clear about human evolution its that
it cannot be explained in terms that would apply to other species. This is
especially obvious with respect to the the rate of human evolution and with
respect to the fact that fossil evidence of human evolution does not conform
to the species-habitat-niche-stasis constraints that all other species are
subject to.
Paul, to support this supposition I'm going to use your own words:
Paul Crowley wrote in message Re: littoral Ape Theory, on Monday May 25,
1998
Firstly, the number of genuses and species among hominids is
unquestionably too high -- by comparison with other taxa. Too
many discoverers of new fossils want to make them a new species.
Secondly, the speed of change among hominids IS remarkably rapid,
and needs its own explanation. <snip> These
provided many opportunities for quasi-speciation among isolated
populations . . . <snip>
In my opinion these statements above show an advanced understanding of what
a true dillema the problem of human evolution really is. It is unique,
distinct, not like that of the other species. Anybody who doesn't
understand this must be, to some degree, largely ignorant of paleontology as
it applies to niches and stasis etc.
The trick to understanding human evolution is to understand why it is off
the rails.
Jim
Marc Verhaegen
Paul Crowley heeft geschreven in bericht <356ac93...@news.indigo.ie>...
><Marc.Ve...@village.uunet.be> wrote:
>
>>Early & gracile australopiths lived in forested areas, esp. gallery
woods...
>>Robusts lived in more open landscapes, not withouth trees, in
marshlands...
>You repeat this like a mantra.
Because you are deaf.
> There is little or no good evidence for this sort of thing.
There is rather good evidence:
Early, gracile:
? Ardipithecus ramidus: ‘Sedimentological, botanical and faunal evidence
suggests a wooded habitat for the Aramis hominids’ (WoldeGabriel et al.,
1994).
? Kanapoi KNM-KP 29281 Australopithecus anamensis: ‘A wide gallery forest
would have almost certainly been present on the large river that brought in
the sediments’ (Leakey et al., 1995).
? Hadar AL.333 A. afarensis: ‘The bones were found in swale-like features
[…] it is very likely that they died and partially rotted at or very near
this site […] this group of hominids was buried in streamside gallery
woodland’ (Radosevich et al., 1992).
? Makapan A. africanus: ‘[…] very different conditions from those prevailing
today. Higher rainfall, fertile, alkaline soils and moderate relief
supported significant patches of sub-tropical forest and thick bush, rather
than savannah. Taphonomic considerations […] suggest that sub-tropical
forest was the hominins’ preferred habitat rather than grassland or
bushveld, and the adaptations of these animals was therefore fitted to a
forest habitat’ (Rayner et al., 1993).
? Taung australopithecine: ‘the clayey matrix from which the Taung cranium
was extracted, and the frequent occurrence of calcite veins and void
fillings within it (Butzer 1974, 1980) do suggest a more humid environment
during its accumulation’ (Partridge, 1985).
Robusts:
? Lake Turkana: ‘The lake margins were generally swampy, with extensive
areas of mudflats […] Australopithecus boisei was more abundant in fluvial
environments, whereas Homo habilis was rare in such environments […]
Australopithecus fossils are more common than Homo both in channel and
floodplain deposits. The gracile hominids […] seem to be more restricted
ecologically to the lake margin than are the robust forms’ (Conroy, 1990).
? Ileret A. boisei: ‘the fossil sample reflects climatic and ecological
environmental conditions differing significantly from those of the present
day. At Ilerat, 1.5 Myr ago, climatic conditions must have been cooler and
more humid than today, and more favourable to extensive forests […] The
prominence of montane forest is particularly striking […] dominated by
Gramineae and Chenopodiaceae appropriate to the margins of a slightly saline
or alkaline lake’ (Bonnefille, 1976).
? Chesowanja A. boisei: ‘The fossiliferous sediments were deposited in a
lagoon […] Abundant root casts […] suggest that the embayment was flanked by
reeds and the presence of calcareous algae indicates that the lagoon was
warm and shallow... relatively stagnant water’ (Carney et al., 1971).
? Olduvai Bed I: A. boisei O.H.5 as well as A. or H. habilis O.H.7 and
O.H.62 were found in the most densely vegetated, wettest condition, with the
highest lake levels (Walter et al., 1991). ‘Fossilized leaves and pollen are
rare in the sediments of Beds I and II, but swamp vegetation is indicated by
abundant vertical roots channels and casts possibly made by some kind of
reed. Fossil rhizomes of papyrus also suggest the presence of marshland
and/or shallow water’ (Conroy, 1990). ‘Cyperaceae fruits were common in H.
habilis habitat (Bonnefille, 1984).
> Hominids (normal definition)
>could walk and their fossils may be found a long way from their
>habitat, especially if their normal habitat was not suitable for
>fossilization.
???
Why do you think the australopith habitat was not suitable for
fossilisation?
>>Apes need their large canines for opening fruits... The males also for
>>intraspecific use.
>
>The opening fruit use for large canines is fairly minor.
Nonsense, the dietary use for canines is the canine size you see in females
(opening fruits, eating bark from trees...
> All primates, other than us, have large canines. Many have little
>dietary application (e.g. male gorillas or male gibbons).
Nonsense.
> Their use in discouraging predators, especially for males, is probably
>their most important value.
Not impossible for the males.
>>Australopiths had a more herbivorous, less frugivorous diet than most
>>present-day apes, so long canines were a handicap.
>Firstly, you've no real evidence for a more herbivorous diet.
Plenty of evidence: short canines, broad pre/molars cf. pandas, microwear...
>Secondly, it would hardly be more herbivorous that of the gorilla
>and they have very large canines.
Robusts no doubt more herbivorous (sedges, reed, see microwear) than
gorillas.
Even some deer have long canines.
Gorilla still partly frugivorous.
> Thirdly, there is no clear way
>that a animal with large canines could adapt to diet that
>required a horizontal (cow-like) motion of the jaws. That motion
>only becomes possible once the large canines have gone; so there
>is no mechanism that could enable a gradual reduction.
No. Simplification.
>Fourthly, once an animal had adapted to such a diet, there is no
>way that large canines could come back (as you assert vis-a-vis
>gorillas).
Why not? The canines were "small", but did not disappear.
(I didn't assert, but I do think it possible that gorillas have regrown
larger canines.)
>Fifthly, you can point to no parallels among any
>other large-bodied (or even small-bodied) mammalian taxa of such
>rapid changes in diet and morphology.
Rapid?? See previous messages.
>>> They'd have had to stand still
>>>in a group, using stones and clubs to keep the predators (or
>>>enemy hominids) at bay.
Do tapirs use clubs to keep predators or enemy tapirs at bay?
>>Rather improbable for Austr. (You're perhaps describing H.erectus?)
>Why improbable for the australopiths? Chimps are nearly there;
>it is not IMO at all hard to see a chimp population that moved to
>more open ground adopting such habits.
The hominid physiology is not suited for open & dry milieus.
Australopiths have dental adaptations for aquatic plants (microwear, see PF
Puech)
>>Leopards were the most dangerous. The smaller austr. could flee into the
>>trees or into the water,
>The water would almost invariably have crocodiles. And leopards
>do the predation on baboons in_the_trees at night.
Crocodiles & leopards don't cooperate. Australopiths had more options to
flee (water/trees) than baboons.
>Australopiths in trees would be much more vulnerable than baboons.
Why??
(and A.boisei males were 3-4 times as large as baboons)
>>You must compare Lucy's locomotion to that of proboscis monkeys, somewhat
>>less arboreal, somewhat more bipedal wading & swimming. I don't see
problems
>>for her children, they could grasp her hairs.
>At some point hominid females went fully bipedal.
Fully bipedal only "recently" in H.sapiens: correlation with basicranial
flexion, eyes underneath brain instead of in front of it, very ventral
foramen magnum (sapiens>neande.>erectus). These are adaptations to make the
eyes look forward or at the ground (wading, beach-combing, walking?) in a
completely bipedal animal. H.erectus' eyes were directed more cranially (to
look at the sky in a fully bipedal creature???)
If our full bipedality was ancient, human infants would have walked much
earlier (zebra & wildebeest babies run from birth).
>At some point
>hominid infants stopped hanging on like other primate infants.
>Until you've sorted out exactly how both happened, you've got
>nowhere in human evolution.
Exactly? Nowhere?? Why?
(& can't you read? It was no problem in the water (cf. diving Fuegian women)
>>(There is no "primate locomotion". Primates are very diverse.)
>
>The is a near-universal one for infants -- on their mother's
>bellies or, occasionally, their backs.
>>Large infants could run or walk or, if necessary, easily sit on their
>>mother's back, whether she was bi-, tri- or quadrupedal.
>How can an infant sit on a vertical back? It could sit on the
>adult's shoulders, but I don't think anyone would claim that that
>was a normal system.
>>Difficult to say which carrying position was commonest for the
>>small infants, but there were a lot of possibilites.
>>Australopiths had a unique lifestyle (studies of CE
>>Oxnard).
>
>All species have a unique lifestyle. Your claim that it was
>"more unique" has no real evidence.
No. See Oxnard's studies (limb proportions etc.): australopith locomotion
was different from humans & different from apes.
(IMO frequently wading, perhaps also frequently swimming but not diving,
graciles still frequently climbing)
> However there are only two
>ways that primate mothers have solved the infant-carrying problem
>(a) the human one -- for most of the time they leave it down
The human way (bipedal carrying in one arm or leaving it down) is derived
from wading or diving ancestors (cf. Fuegian women) that come to live more
on the land.
>(b) all other primates -- they carry it around for every minute
>of every day, which is possible because it sticks like a bug.
No problem
>>Chimp mothers with small infants often walk on three
>>legs, holding the baby with one arm.
>
>This is correct for new-borns or sick infants; but it is not the
>normal system. Chimps mothers need both hands free to climb,
>run, forage or protect themselves.
>
>>They did not have to travel far. Just a few (deci)metres to get
>>the next food item.
>
>This is nonsense (if imaginative nonsense).
No nonsense. See gorillas feeding in swamps or in vegetation.
> What other large
>animals (let alone primates) are in this fortunate position?
Gorilla, bamboo bear...
>Perhaps the sloth. While the australopiths were clearly not
>great at getting around, there would have been some selection for
>travelling capacity. You can't hypothesize a "sloth-niche"
>simply to suit an argument.
???
>>I think you have to see more wildlife films of apes.
>
>I record loads and study them carefully. (There's progamme on
>proboscis monkeys on BBC2 tomorrow (Wednesday 27th 14:45) if you
>get that channel).
Thanks
>>(Hominids are: australopiths, chimps, gorillas, humans - see molec.data &
>>see below.
>
>If you are going to define common words in your own peculiar way,
>no one will have any idea what you are talking about.
Not my words: molec.biologists. Calling australopiths & humans hominid, and
chimps & gorillas not-hominid, is nonsense. See splitting times.
>>Both australopiths & extinct Homo lived at the edge between land & water.
If
>>the danger came from the land, they fleed to the water (or trees in the
case
>>of the australopiths), etc. Homo probably used stones or clubs,
>>australopiths rarely.
>
>Large cats are not afraid of water; many can climb trees. Quite
>apart from the baby-carrying problem, the australopiths would be
>much slower at running, climbing, and probably swimming than
>baboons. The problem of predation has to be taken seriously.
They were faster & more agile than leopards in swimming & climbing.
>>Australopiths (group animal) escaped predators +- like tapirs or capybaras
>>or proboscis monkeys do: running to the land or to the water or to the
>>trees, according to where the danger comes from. The biggest problem is
>>spotting the enemy before he's too near.
>
>Spotting the enemy at a distance is only useful if you're faster
>than him or have a close refuge. Australopiths would have been
>impossibly slow (especially females with infants) and had few
>refuges.
See above.
The graciles were not slow, & probably agile in the trees. The robusts
(males) were huge animals.
Do you know how gorillas keep off leopards etc.? Males defending the group?
>>(Stones & clubs must be carried. Apes & monkeys can handle clubs, but
prefer
>>not to use them frequently.)
>I accept that stones and clubs must be carried. This would have
>been a very important motivation for bipedalism.
It's the other way round of course: carrying a club was possible because
Homo was bipedal. And he was bipedal because his diving/wading past had
forced him into this (slow & costly) posture.
> Although I
>doubt if the australopiths travelled much. It could well have
>been the development by the Homo line of a capacity to carry
>things (like clubs, stones, food) by, say, using animal skins
>that enabled them to travel more effectively. Only then would
>they have acquired the longer legs and more efficient stride.
Very "recently" see above
>>>The loss of large canines was a remarkable development.
>>
>>Not for herbivores!
>
>How does a animal with large canines switch to a herbivorous
>diet?
What animal do you mean?
(Australopiths show all lengths of canines from as long as an incisor to
almost twice as long, but canines were never lost.)
> Can you show such a change elsewhere in nature? (The
>answer here is "Of course, not.)
See tragulids & cervids, eg.
>>We see a relative canine reduction from graciles to
>>robusts, just as expected from their diet. I can't see any problem for
>>explaining the australopith canines.
>
>(a) Just another unique event in evolution which only happens in
>the hominid (usual sense) line.
Unique??? See tragulids & cervid
>(b) No possible way it could
>happen (c) leaves no defence equipment.
See above
>>> It is up to
>>>you to come up with your own reasons for your proposed loss and
>>>re-acquisition of large canines.
Diet! see above. Teeth are used for eating, you know.
>>No loss & re-acquisition (eg, oscilations of larger & smaller beaks in
>>Galŕpagos finches according to the wetness or dryness of the previous
>>seasons), but strong overlap between apes/australopiths/Homo:
>
>Gradually expanding or reducing beak size is a very different
>operation from losing a feature that has been universal among
>primates for at least 60 Myr.
Not losing at all.
> Natural variation in beak size can
>readily be observed in any birds. Natural selection can make the
>average size larger or smaller. That is easy to see. But for
>all primates (other than us) losing their large canines would be
>like losing their legs. They would lose their whole defence
>function. It would mean near-instant death. It just couldn't
>happen.
Not losing.
For a discussion of canine size & variation & evolution in hominids, see
Verhaegen 1994 Hum.Evol.9:121
>>- in gorillas & chimps "with advancing age, canines thend to wear flat to
>>the level of the incisors"
>
>You show quotes. What is your source here?
Ryan & Johanson 1989 JHE 18:235
(refs in my paper above)
> This is very much
>contrary to my understanding. I strongly doubt if male canines
>wear down. Old chimp males often lose them, but they are far too
>large to be worn down to molar level.
Keep doubting
>>& bonobos "have rel.smal & only slightly projecting canine teeth"
>
>What is your source for this? Does it apply to males?
Zihlman etc.1978 Nat.275:744
>>Evolution is gradual: no niche-swapping, but diet-overlapping & gradual
shift.
>
>
>>Burial?? dogs??
>
>These were argued here in some rather long threads.
Burial in Neandertals & sapiens, certainly not in australopiths.
Dogs +- 100,000 years.
>>Evolution exists, you know. It's usu. slow (oscillating = slow on the long
>>run), but when the environment changes (island colonisation, climatic
>>changes...) it can be "very fast".
>
>Exactly. But you use the slow "drift" notion for all your niche-changes.
???
I use the gradual model for all my adaptations.
(In fact I didn't "use", it just came automatically, the more information I
had)
> I get the impression that you see a population about
>the former size of bonobos gradually shifting from a frugivous to
>a herbivorous diet.. That, in my view, is impossible.
In your view
>The environment did not change that much.
Does the environment change if you start from the coast & colonise upstream
milieus?
(coast = more shellfish, upstream = more plants, I guess)
> If there was a viable
>frugivorous niche, it won't go away. The only way I see that is
>possible, in the very tight timescale we are allowed
3 times 4-8 my = 'tight' ?
(3 times: Pan, Homo, Gorilla)
>, is for a
>small isolated population to find a whole new way of life, and
>change radically. This IS possible and has been known to happen
>thousands of times (e.g. Darwin's finches, fruit flies on Hawaii,
>cichlid fish in Lake Victoria). This new species will then
>expand back to its parent species's territory and IF its_niche_
>_overlaps_with its parent and IF it has major advantages, it may
>wipe it out. Since both of these conditions are unlikely, the
>parent species will normally continue to exist. But none of your
>hypothetical parent species exist.
Perhaps we should see the "stock" population along the shores of the whole
Indian Ocean, Red Sea etc. & giving offshoots along the rivers inland. Such
geograph.linear species "must" speciate.
Marc
Marc Verhaegen
Jim McGinn heeft geschreven in bericht <#UZKsEQi9GA.179@uppubnews03>...
>
>Marc Verhaegen wrote in message <6k8msv$ep3$1...@xenon.inbe.net>...
>>
>>Paul Crowley heeft geschreven in bericht
>><356771e4...@news.indigo.ie>...
>>>On Thu, 21 May 1998 19:45:20 -0700, "Norman K. McPhail"
>>><no...@socal.wanet.com> wrote:
>>
>>>Whenever you find yourself describing human evolution in terms
>>>that you would never apply to other species, then you're
>>>probably off the rails -- and certainly if the matter precedes
>>>language.
>>
>>Beautifully said!
>The trick to understanding human evolution is to understand why it is off
the rails.
It's not off the rails, perhaps the human train has taken a special
direction, but it's still on the rails.
The comparative method is the only safe method for solving evolutionary
puzzles.
For instance, Roger Crinion, a correspondent of Elaine Morgan, seems to have
solved the problem of laryngeal descent by comparing the human mounth &
throat with all sorts of mammals (carnivores, bovids, cetaceans, pinnipeds,
bats, primates..).
Humans differ from chimps in having smaller mouth, rounder toungue, vaulted
palate, less palatal ridges, & descended larynx. All these features in
mammals are correlated with suction feeding (of grubs, fruits, molluscs).
Probably the descended larynx created a lower pressure in the mouth cavity
for stronger suction.
Marc
Jim McGinn
Marc Verhaegen wrote in message <6khol9$ao7$1...@xenon.inbe.net>...
>
>Jim McGinn heeft geschreven in bericht <#UZKsEQi9GA.179@uppubnews03>...
>>
>>Marc Verhaegen wrote in message <6k8msv$ep3$1...@xenon.inbe.net>...
>>>
>>>Paul Crowley heeft geschreven in bericht
>>><356771e4...@news.indigo.ie>...
>>>>On Thu, 21 May 1998 19:45:20 -0700, "Norman K. McPhail"
>>>><no...@socal.wanet.com> wrote:
>>>
>>>>Whenever you find yourself describing human evolution in terms
>>>>that you would never apply to other species, then you're
>>>>probably off the rails -- and certainly if the matter precedes
>>>>language.
>>>
>>>Beautifully said!
>
>>The trick to understanding human evolution is to understand why it is off
>the rails.
>
>
>It's not off the rails, perhaps the human train has taken a special
>direction, but it's still on the rails.
>The comparative method is the only safe method for solving evolutionary
>puzzles.
>
>For instance, Roger Crinion, a correspondent of Elaine Morgan, seems to
have
>solved the problem of laryngeal descent by comparing the human mounth &
>throat with all sorts of mammals (carnivores, bovids, cetaceans, pinnipeds,
>bats, primates..).
>Humans differ from chimps in having smaller mouth, rounder toungue, vaulted
>palate, less palatal ridges, & descended larynx. All these features in
>mammals are correlated with suction feeding (of grubs, fruits, molluscs).
>Probably the descended larynx created a lower pressure in the mouth cavity
>for stronger suction.
>
>Marc
>
>
In any kind of a unique species, a species that takes a new and uncharted
course as obviously the human species has done when it--due to some yet
unexplained causal factors--broke out of the constraints of being a niche
specific species, we should expect that the evolution of new traits will
tend to draw from the species historical phylogeny. In other words, humans,
being mammals will tend to find new strategies from the same genetic bag of
tricks that any and all mammals draw from. Consequently it is hardly a
surprize that we see similarity in the strategies of humans to other
mammals. In fact it would be surprizing if we did not.
My general impression of the proponents of AAT (as well as SAT) is that they
(you) would do well to get a better understanding of more of the
paleontological tradition as it applies to niches, stasis, and phylogeny.
As I see it AAT is off on a tangent. The comparative method that you
espouse is bound to give you a false sense of success. Worst of all it is
this kind of thinking that has caused us to gloss over what I think is the
most important clue to human evolution, that being the how and why the
humans species (at some point 4 to 5 million years ago) broke out of the
constraints of being a niche specific species.
Paul Crowley
>>Paul Crowley heeft geschreven in bericht
>>>Whenever you find yourself describing human evolution in terms
>>>that you would never apply to other species, then you're
>>>probably off the rails -- and certainly if the matter precedes
>>>language.
>This is simply wrong. If anything is clear about human evolution its that
>it cannot be explained in terms that would apply to other species.
You're missing the context in which I used "terms you would never
apply to other species". Take a look at Norman McPhail's site:
http://204.94.86.93
and you'll see all sorts of talk about "heroes" and such-like.
Seeing hominids as supermen, talking about "supreme opportunists"
or "great generalists" is usually IMO an easy way to avoid
thought. There is an enormous amount of populist junk like this
around. Worse, many of these ideas infect stuff that claims to
be serious.
>This is especially obvious with respect to the the rate of
>human evolution
Human evolution appears to run at a faster rate; while the
phenenon needs explanation, it doesn't put hominids into a
special category.
>and with respect to the fact that fossil evidence of human
>evolution does not conform to the species-habitat-niche-
>stasis constraints that all other species are subject to.
There are two possibilities here (a) the data is misleading, or
(b) hominids really can swap niches.
The first is IMO much more likely. The strange habitats that
hominids are supposed to have occupied are all dated to before
about 1.5 mya. In spite of remarkable advances in technology and
(presumably) language after that, there are no such habitats
until within the last 10 Kyr when highly sophisticated technology
arrives. And even then hominids weren't able to get into the
savanna, where they are supposed to have evolved.
>The trick to understanding human evolution is to understand why it is off
>the rails.
The first step is assume hominids work within the same parameters
and only when there are definitely no answers there consider
possibly moving outside them.
Paul.
Norman K. McPhail
Jim McGinn wrote:
>
> Marc Verhaegen wrote in message <6khol9$ao7$1...@xenon.inbe.net>...
> >
> >Jim McGinn heeft geschreven in bericht <#UZKsEQi9GA.179@uppubnews03>...
> >>
> >>Marc Verhaegen wrote in message <6k8msv$ep3$1...@xenon.inbe.net>...
> >>>
> >>>>On Thu, 21 May 1998 19:45:20 -0700, "Norman K. McPhail"
> >>>><no...@socal.wanet.com> wrote:
> >>>
> >>>>Whenever you find yourself describing human evolution in terms
> >>>>that you would never apply to other species, then you're
> >>>>probably off the rails -- and certainly if the matter precedes
> >>>>language.
> >>>
> >
> >>The trick to understanding human evolution is to understand why it is off
> >the rails.
> >
> >
> >direction, but it's still on the rails.
> >The comparative method is the only safe method for solving evolutionary
> >puzzles.
> >
> >
> >Marc
> >
> >
>
> In any kind of a unique species, a species that takes a new and uncharted
> course as obviously the human species has done when it--due to some yet
> unexplained causal factors--broke out of the constraints of being a niche
> specific species, we should expect that the evolution of new traits will
> tend to draw from the species historical phylogeny. In other words, humans,
> being mammals will tend to find new strategies from the same genetic bag of
> tricks that any and all mammals draw from. Consequently it is hardly a
> surprize that we see similarity in the strategies of humans to other
> mammals. In fact it would be surprizing if we did not.
>
> My general impression of the proponents of AAT (as well as SAT) is that they
> (you) would do well to get a better understanding of more of the
> paleontological tradition as it applies to niches, stasis, and phylogeny.
>
> As I see it AAT is off on a tangent. The comparative method that you
> espouse is bound to give you a false sense of success. Worst of all it is
> this kind of thinking that has caused us to gloss over what I think is the
> most important clue to human evolution, that being the how and why the
> humans species (at some point 4 to 5 million years ago) broke out of the
> constraints of being a niche specific species.
Jim:
Bill Calvin does a fair job of explaining how our forebears may have
gained some of these new emerging properties. This is what has always
made the most sense to me. I have no trouble at all in understanding
how we can be both the same as all the other life forms out there and
differ from them at the same time. Why can't we have some emergent
properties? Why this is such a problem for some people is beyond me?
I also don't understand why they get so excited about the
self-organizing process. The examples of how emerging properties
self-organize can be seen in quantum physics, chemistry, organic
chemistry, molecular biology and astro physics. Self-organizing systems
are the rule not the exception. How else can we explain the emergence
of things like atoms, molecules, single cell life, multi cell life and
sexual reproduction? So why can't what I like to call human
understanding be an emergent property?
They can call it nonsense, off the rails, and any other names they want.
The name calling and adversarial attitude can't change the way things
are. No matter what any of us do or say, we can't make human
understanding and human biology identical. Besides, why would anyone
want to claim that our understanding is a form of life? What sense does
that make?
It seems obvious to me that human understanding is an emergent property.
How can it be anything but a different property. We don't see it any
where else in nature. In fact, our own understanding is so amazing and
mysterious that we are just beginning to understand it.
Human understanding comes through life. So it is not other than
physics, biology, ecology and the complex processes of evolution. Yet
human understanding is also different and more than any of these
things.
It is not of the same logical type as life. Who can't see that our
understanding is as different from life as life is from the lifeless
realm of physics?
I don't think there would be many who would try to argue that life
doesn't come through and differ from the lifeless realms of quantum and
macro physics. Even if we could fully explain the phenomenon of life
with some theory or law of physics, what sense would it make to say that
life isn't also an emergent property that differs from physics in many
ways and qualities.
Thus, I think that human understanding is of a different logical type
from life. You seem to be at least heading in this direction.
Norm McPhail
Norman K. McPhail
>
> You're missing the context in which I used "terms you would never
> apply to other species". Take a look at Norman McPhail's site:
> http://204.94.86.93
> and you'll see all sorts of talk about "heroes" and such-like.
> Seeing hominids as supermen, talking about "supreme opportunists"
> or "great generalists" is usually IMO an easy way to avoid
> thought. There is an enormous amount of populist junk like this
> around. Worse, many of these ideas infect stuff that claims to
> be serious.
>
Paul spent about three minutes scanning through a few pages posting
ratings for parts he didn't even read. He has no clue about what the
site is about and what the full content is like. His distortions are
about as accurate as most of the postings I've seen him make to this ng.
The site contains a treatment for a 33 part documentary TV series. It
is not an academic paper and never makes any such claims.
So as usual, the one pointing the finger is the one most guilty of
making reductionistic, deterministic mistatements. I find his defective
ideas, adversarial comments and abusive attitude unworthy of further
attention. But no doubt he will continue to fight on.
Norm
Drox
Paul Crowley wrote:
> Most primates have large canines. The australopiths lost theirs.
> This *must* mean that they no longer needed them, which *must*
> mean that they had some other defence.
Must they? I have to wonder... do "most primates" use their large
canines for defense? Against anything other than members of their own
species? I must admit I've never seen it. AFAIK the large canines
(found even in tree-dwelling primarily-herbivorous species) are not so
much for interspecies defense as for intraspecies intimidation-display
and occasional intraspecies fighting.
-Drox
Paul Crowley
>Paul Crowley heeft geschreven in bericht <356ac93...@news.indigo.ie>...
>> Hominids (normal definition)
>>could walk and their fossils may be found a long way from their
>>habitat, especially if their normal habitat was not suitable for
>>fossilization.
>
>Why do you think the australopith habitat was not suitable for
>fossilisation?
I maintain that the hominid (normal definition) habitat for the
last 5 Myr has been the littoral. It's where, broadly speaking,
they concentrate today. Littorals are poor places for
fossilization. There absorb enormous amounts of energy and sea
levels are constantly rising and falling, destroying the
evidence. The obvious way for a littoral population to expand
is to go inland. And almost every generation would export its
surplus young in that direction. Generally they would finish up
beside some lake or water hole, possibly buried in a shallow
grave by their companions, sometimes suffering from the effects
of vitamin-A poisoning after eating their dogs. This is the only
reasonable account for the condition of my favorite fossil KNM-ER
1808. Another vitamin-A-poisoned fossil was found at Venosa in
Italy dated to about 0.5 mya.
>>>Apes need their large canines for opening fruits... The males also for
>>>intraspecific use.
>>
>>The opening fruit use for large canines is fairly minor.
>
>Nonsense, the dietary use for canines is the canine size you see in females
>(opening fruits, eating bark from trees...
>
>> All primates, other than us, have large canines. Many have little
>>dietary application (e.g. male gorillas or male gibbons).
>
>Nonsense.
Large canines are expensive. The hominid (n.d.) line lost theirs
quite quickly at the earliest opportunity. Rather than say
"nonsense" you need to explain why all primates, other than us,
possess them, considering they have an enormous range of diets.
You also have to explain why males generally have much larger
ones than females. Males and females of the same species usually
have the same diet. Male gorillas have enormous canines. They
eat much the same as females.
Once an animal has such expensive equipment it will, of course,
use it for as many purposes as possible. Male chimps use them to
kill prey. But they don't have to. Goodall reports that Evered
lost three of his four canines in old age, but was still a
skilled hunter. He developed a technique of swinging the body of
the prey aninal against a tree trunk to kill it.
>> Thirdly, there is no clear way
>>that a animal with large canines could adapt to diet that
>>required a horizontal (cow-like) motion of the jaws. That motion
>>only becomes possible once the large canines have gone; so there
>>is no mechanism that could enable a gradual reduction.
>
>No. Simplification.
How is it a simplification? The interlocking nature of the large
canines of all our close relatives prevents horizontal motion
with closed or near-closed jaws. How does such an animal switch
to the cow-like (or human-like) rotary motion? IMO it is quite
clear that the canines have to be reduced in size for quite
different reasons _first_.
>>Fourthly, once an animal had adapted to such a diet, there is no
>>way that large canines could come back (as you assert vis-a-vis
>>gorillas).
>
>Why not? The canines were "small", but did not disappear.
Imagine us re-growing large canines! We would _first_ have to
change our method of mastication. Why on earth would we?
>(I didn't assert, but I do think it possible that gorillas have regrown
>larger canines.)
If gorillas are descended from australopiths, what else is
possible?
>>Fifthly, you can point to no parallels among any
>>other large-bodied (or even small-bodied) mammalian taxa of such
>>rapid changes in diet and morphology.
>
>Rapid?? See previous messages.
As you well know, changes in dentition are extraordinarily slow
in all taxa. They are distinctive to orders, families and
genera. Your disregard of the permanence of their nature is
cavalier.
>>>> They'd have had to stand still
>>>>in a group, using stones and clubs to keep the predators (or
>>>>enemy hominids) at bay.
>
>Do tapirs use clubs to keep predators or enemy tapirs at bay?
I don't get your analogy. Primates (and especially us and
chimps) are social animals that aggressively attack neighbouring
groups. Tapirs are solitary animals, that don't have the
equipment for this activity anyway. Tapirs use speed (in the
context of their habitat) to escape predators. They also have
sharp teeth and fight viciously when cornered.
>>Why improbable for the australopiths? Chimps are nearly there;
>>it is not IMO at all hard to see a chimp population that moved to
>>more open ground adopting such habits.
>
>The hominid physiology is not suited for open & dry milieus.
I didn't say anything about open and dry milieu. I meant
"slightly more open than chimp habitat" i.e. not too many trees
to get in the way of swinging clubs, possibly a beach.
>>Australopiths in trees would be much more vulnerable than baboons.
>
>Why??
>(and A.boisei males were 3-4 times as large as baboons)
Being bipedal, australopiths would be far less capable in trees.
And they don't have the other baboon adaptations to trees, such
as the iscial calosities. Being heavier, they would not be able
to get to the higher, smaller branches. So size is a
disadvantage. Recent infra-red films of leopards hunting baboons
shows that the baboons are effectively blind at night, whereas
leopards can see. The leopard doesn't always use subterfuge. It
lets the baboons know it's there, and panics them into error.
>(& can't you read? It was no problem in the water (cf. diving Fuegian women)
Sorry I had no idea that you believed hominids spent all their
time in the water.
>>I accept that stones and clubs must be carried. This would have
>>been a very important motivation for bipedalism.
>
>It's the other way round of course: carrying a club was possible because
>Homo was bipedal. And he was bipedal because his diving/wading past had
>forced him into this (slow & costly) posture.
I accept the now common view that the chimp (5 mya) was our
ancestor. You may go for another CA. In any case it was probably
using clubs much as chimps do today. This use needs a kind of
bipedalism. All you have to do is provide an environment that
encourage that and you have bipedalism in males. (Females are,
of course, another story).
>>>We see a relative canine reduction from graciles to
>>>robusts, just as expected from their diet. I can't see any problem for
>>>explaining the australopith canines.
>Unique??? See tragulids & cervid
When did they lose their canines?
>>>& bonobos "have rel.smal & only slightly projecting canine teeth"
>>
>>What is your source for this? Does it apply to males?
>
>Zihlman etc.1978 Nat.275:744
Zihlman in 1978 about Bonobos, is about the worst sort of
reference possible. The famous Kanzi is a bonobo; there is
nothing small, or "non-projecting" about his canines.
Paul.
Paul Crowley
On Wed, 27 May 1998 22:25:14 -0500, Drox <dr...@hotmail.com>
wrote:
>Paul Crowley wrote:
>> Most primates have large canines. The australopiths lost theirs.
>> This *must* mean that they no longer needed them, which *must*
>> mean that they had some other defence.
>
>Must they? I have to wonder... do "most primates" use their large
>canines for defense? Against anything other than members of their own
>species? I must admit I've never seen it.
Monkeys are preyed upon by chimps, baboons, eagles and leopards.
Males do their best to defend females and infants, using their
only weapons -- large canines. See the films of chimp hunts.
>AFAIK the large canines
>(found even in tree-dwelling primarily-herbivorous species) are not so
>much for interspecies defense as for intraspecies intimidation-display
>and occasional intraspecies fighting.
We are talking about australopiths which are to be compared with
largely terrestrial primates, such as baboons or chimps. They
certainly rely on their canines for defence against predators,
such as leopards (where perhaps defence often takes the form of
diurnal attacks).
In any case, why did australopiths become an exception to a near
-universal primate rule? If you say canines were used for
intraspecies aggression, what was the big change with
australopiths? The sexual dimorphism is usually held to
indicate a higher level of male-to-male competition.
The main changes were bipedalism, the acquisition of hands
designed to grasp, and the loss of large canines. These fit far
too well with club wielding for it not to be the main hypothesis.
Paul.
Paul Crowley
On Wed, 27 May 1998 16:01:12 -0700, "Norman K. McPhail"
<no...@socal.wanet.com> wrote:
>Paul Crowley wrote:
>>
>> You're missing the context in which I used "terms you would never
>> apply to other species". Take a look at Norman McPhail's site:
>> http://204.94.86.93
>> and you'll see all sorts of talk about "heroes" and such-like.
>> Seeing hominids as supermen, talking about "supreme opportunists"
>> or "great generalists" is usually IMO an easy way to avoid
>> thought. There is an enormous amount of populist junk like this
>> around. Worse, many of these ideas infect stuff that claims to
>> be serious.
>
>Paul spent about three minutes scanning through a few pages
So you get all that info down? Actually I downloaded the one
section I was interested in, and read it later. That's how I
quoted from it.
>posting ratings for parts he didn't even read.
I didn't mean to post anything. Maybe I looked at the options,
but there was no posting button. You should clean the page up.
Paul.
Jim McGinn
Norman K. McPhail wrote in message <356C9B...@socal.wanet.com>...
>Paul Crowley wrote:
>>
>> On Tue, 26 May 1998 16:52:51 -0700, "Jim McGinn"
>> <jimm...@msn.com> wrote:
>>
>> >>Paul Crowley heeft geschreven in bericht
>
>>
>> You're missing the context in which I used "terms you would never
>> apply to other species". Take a look at Norman McPhail's site:
>> http://204.94.86.93
>> and you'll see all sorts of talk about "heroes" and such-like.
>> Seeing hominids as supermen, talking about "supreme opportunists"
>> or "great generalists" is usually IMO an easy way to avoid
>> thought. There is an enormous amount of populist junk like this
>> around. Worse, many of these ideas infect stuff that claims to
>> be serious.
>>
>
>
>
>Paul spent about three minutes scanning through a few pages posting
>ratings for parts he didn't even read. He has no clue about what the
>site is about and what the full content is like. His distortions are
>about as accurate as most of the postings I've seen him make to this ng.
>
>The site contains a treatment for a 33 part documentary TV series. It
>is not an academic paper and never makes any such claims.
>
>So as usual, the one pointing the finger is the one most guilty of
>making reductionistic, deterministic mistatements. I find his defective
>ideas, adversarial comments and abusive attitude unworthy of further
>attention. But no doubt he will continue to fight on.
>
>Norm
Boy have you gotten the wrong impression from my previous post. I am the
most deterministic, reductionistic, and mechanistic (in addition to being
relativistic as opposed to being absolutistic) scientist that I know. I'm
an extremist on this point. I don't allow for any kind of thinking that in
any way resembles vitalism. I don't even allow for the existence of
stochastic processes (ie. genetic drift) as a causal factor. Moreover I
find reading S.J. Gould to be very frustrating because he opens the door to
this kind of nonscientific thinking.
I breezed through your website. It has nice pictures but it isn't
scientific.
I read two books on the "Science" of complexity, one by Waldrop and the
other by Lewin. As I see it Complexity is little more than the restating of
what we already know using non-linear mathematics. To the extent that the
Science of Complexity stays within those boundaries it is useful.
Unfortunately the proponents of Complexity have a tendency to proclaim it to
be more than it really is. There critics sometimes refer to it,
sarcastically, as, "a fact free science."
I have found complexity theory useful for helping us understand the
boundary conditions by which life might have first come about on this
planet. With respect to human evolution I see nothing to be gained by
saying that human consciousness is "an emergent quality." Whenever I hear
the term emergence my bullshit warning signal goes off. In my opinion
emergence is just a pseudo-scientific way of saying growth. Here's an
experiment you might try. Whenever you see or are tempted to use the word
emergence replace it with the word growth. You will find that it doesn't
lose any of its meaning.
My approach to human evolution is very much at odds with the current
paradigm in this field. It is unfortunate that the proponents of the
current paradigm--who very often do not recognize that they are such--are
unable to see beyond the limitations of their paradigm to realize that there
are options that don't involve the scientifically untenable approach that
you are proposing.
Jim McGinn
Jim McGinn
Paul Crowley wrote in message <356c6209...@news.indigo.ie>...
>On Tue, 26 May 1998 16:52:51 -0700, "Jim McGinn"
><jimm...@msn.com> wrote:
>
>>>Paul Crowley heeft geschreven in bericht
>>>>Whenever you find yourself describing human evolution in terms
>>>>that you would never apply to other species, then you're
>>>>probably off the rails -- and certainly if the matter precedes
>>>>language.
>
>>This is simply wrong. If anything is clear about human evolution its that
>>it cannot be explained in terms that would apply to other species.
>
>You're missing the context in which I used "terms you would never
>apply to other species". Take a look at Norman McPhail's site:
>http://204.94.86.93
You're right, I did misunderstand the context. I took a look a Norm's site.
As soon as I read the term emergence I knew what I would find. It's funny
that some people (most notably the proponents of the "science" of
Complexity) seem to think that a non-mechanistic, non-reductionist, and
non-deterministic approaches are alternative methods to approaching science
when in actuality they are, by definition, non-scientific.
>and you'll see all sorts of talk about "heroes" and such-like.
>Seeing hominids as supermen, talking about "supreme opportunists"
>or "great generalists" is usually IMO an easy way to avoid
>thought.
I couldn't agree more.
>There is an enormous amount of populist junk like this
>around. Worse, many of these ideas infect stuff that claims to
>be serious.
Ditto.
>
>>This is especially obvious with respect to the the rate of
>>human evolution
>
>Human evolution appears to run at a faster rate; while the
>phenenon needs explanation, it doesn't put hominids into a
>special category.
I disagree. Human evolution is anamolous. IMO this is obvious not only in
the fossil record but in the morphology of present-day humans.
>
>>and with respect to the fact that fossil evidence of human
>>evolution does not conform to the species-habitat-niche-
>>stasis constraints that all other species are subject to.
>
>There are two possibilities here (a) the data is misleading, or
>(b) hominids really can swap niches.
I would add to this the following: (c) hominids broke out of being niche
specific altogether.
>
>The first is IMO much more likely. The strange habitats that
>hominids are supposed to have occupied are all dated to before
>about 1.5 mya.
I know what you are saying here. My only caution--and this is something for
which I think you are aware--is that we don't make the mistake (as seems to
be the habit of MV) of too closely associating niche with habitat. They
cannot be used interchangeably.
>In spite of remarkable advances in technology and
>(presumably) language after that, there are no such habitats
>until within the last 10 Kyr when highly sophisticated technology
>arrives.
I have work-arounds for this problem. They are too involved (and too
sketchy) to go into in this Newsgroup. They involve the existence of
Continental Glaciers.
>And even then hominids weren't able to get into the
>savanna, where they are supposed to have evolved.
I don't think anybody who is immersed in this field takes the savanna theory
(in the literal sense of it being what caused us to first become bipedal)
all that seriously any more.
>
>>The trick to understanding human evolution is to understand why it is off
>>the rails.
>
>The first step is assume hominids work within the same parameters
>and only when there are definitely no answers there consider
>possibly moving outside them.
Being a hardline Darwinist my approach never strays outside the parameters
of natural selection. However, my being a proponent of traditional natural
selection should not bring one to conclude that, therefore, my appoach must
carry forth the assumption that all species must be niche specific. The
trick to understanding human evolution is to figure out what the situational
factors were that caused our ancestors, some 4 to 5 million years ago, to
break out of being niche specific.
>
>Paul.
Norman K. McPhail
Jim McGinn wrote:
>
> Norman K. McPhail wrote in message <356C9B...@socal.wanet.com>...
> >Paul Crowley wrote:
> >>
> >> <jimm...@msn.com> wrote:
> >>
> >> >>Paul Crowley heeft geschreven in bericht
> >
> >>
>
> Boy have you gotten the wrong impression from my previous post. I am the
> most deterministic, reductionistic, and mechanistic (in addition to being
> relativistic as opposed to being absolutistic) scientist that I know.
This is the second time this year I've been wrong. And boy was I wrong.
How did I get such a wrong impression? Perhaps because as you say, you
are relativistic? Regardless, I still found a lot that rang true in the
post you refer to.
> I'm
> an extremist on this point. I don't allow for any kind of thinking that in
> any way resembles vitalism. I don't even allow for the existence of
> stochastic processes (ie. genetic drift) as a causal factor.
How do you stand on the idea of sexual selection and fitness selection?
Do you think there is room for selection that is related to things other
than pure deterministic fitness?
Moreover I
> find reading S.J. Gould to be very frustrating because he opens the door to
> this kind of nonscientific thinking.
>
> I breezed through your website. It has nice pictures but it isn't
> scientific.
I agree, it's not scientific in the narrow sense I assume you use and
define the term. In fact, I go to lengths to say where I think what we
normally call science is useful and where I think it causes a lot of
grief. This is one of the main points of the proposed documentary TV
series.
To repeat, the site is a treatment for this proposed TV series, nothing
more or less. I never claimed to be a scientist. And it's not
surprising that the contents are looked down on by most scientists.
Since I've also never written a script or a treatment before, it's not
surprising that the contents don't pass muster from the TV
specialists/professionals either. In fact, you would not be too far
afield if you made the blanket statement that lots of people find the
site trivial speculation. What would you expect from someone with no
academic credentials to speak of and no experience in the field of
documentary film production.
I will wholeheartedly agree with all of the above. In fact, I take
great pains to point all this out in the preface and elsewhere. So I've
tried to make all this as clear as I can to those who visit the site.
> I read two books on the "Science" of complexity, one by Waldrop and the
> other by Lewin. As I see it Complexity is little more than the restating of
> what we already know using non-linear mathematics. To the extent that the
> Science of Complexity stays within those boundaries it is useful.
> Unfortunately the proponents of Complexity have a tendency to proclaim it to
> be more than it really is. There critics sometimes refer to it,
> sarcastically, as, "a fact free science."
You might be interested to learn that I think complexity theory is less
than sound too.
> I have found complexity theory useful for helping us understand the
> boundary conditions by which life might have first come about on this
> planet.
Do you think that some form of altermative thought mode might also be
useful in understanding the margins between life and thought? Or do you
reduce these to the same thing?
> With respect to human evolution I see nothing to be gained by
> saying that human consciousness is "an emergent quality."
I agree with this mainly because I find that the notion of consciousness
is a confusion of logical types. But if you are willing to say that
some human traits and qualities are different and interesting when
compared to what we see in other life forms, then perhaps you might be
willing to consider the use of alternate ways of learning about these
traits and qualities. The whole objective, as I see it, is simply to
learn more about who and what we are.
> Whenever I hear
> the term emergence my bullshit warning signal goes off. In my opinion
> emergence is just a pseudo-scientific way of saying growth. Here's an
> experiment you might try. Whenever you see or are tempted to use the word
> emergence replace it with the word growth. You will find that it doesn't
> lose any of its meaning.
So you might say that human understanding has "grown" out of the
experiences and processes our forebears went through. I think this is a
good way to express this notion.
> My approach to human evolution is very much at odds with the current
> paradigm in this field. It is unfortunate that the proponents of the
> current paradigm--who very often do not recognize that they are > such--are
> unable to see beyond the limitations of their paradigm to realize that there
> are options that don't involve the scientifically untenable approach that
> you are proposing.
I would just like to add to this last point that I agree that THE DAWN
OF HUMAN UNDERSTANDING site uses a "...scientifically untenable
approach..." And that is one of the main points I try to make
throughout the series.
What I'm suggesting is that science only has a good grasp of the realms
of physics and biology. Further, I think that science is out of it's
league when it comes to figuring out what somethning like human
understanding is.
Thus, we both seem to agree that science can tell us a lot about
evolution, physics, biology and human understanding. And I gather you
feel that science can one day give us a full and complete account of
human understanding.
Where I think we disagree is that I say that unless science changes some
of it's basic assumptions and thought modes, it will never be able to
explain all of what I am calling human understanding. In fact, I think
science can only hope to explain about half the truth when it comes to
human understanding. This is one of my main points.
I would welcome further discussion on this issue.
Norm McPhail
Marc Verhaegen
Gerrit Hanenburg >Marc Verhaegen
>
>>Then again, is Hanenburg always so biased in his data?
>>Why does he omit the even more numerous apelike features in the
australopiths??
>
australopiths", remember?
Okay, but there is "typical" & "typical". What is really typical in humans
is, eg, the extreme brain size & leg length - absent in monkeys,
australopiths & all apes (including bonobos & immature apes).
>>Most of the listed features can be grouped in functionally related
adaptations.
>>For instance, the broad pelvis (unlike humans & apes) with the laterally
>>expanded alae, the long femoral necks, high bicondylar angle are -
together
>>with the apelike small femoral heads & short femoral shafts - are the
>>expressions of the same adaptation: better abduction of the thighs (is
seen
>>in some swimming mammals & seems to suggest that the australopiths not
only
>>waded bipedally but also frequently swam - the same is true for the
>>australopith feet). These are certainly not adaptations for humanlike
>>bipedality: in that case the pelvis should have been narrower, the femoral
>>heads much larger, etc.
>
>These features function as a lateral balancing system. If you want
>better abduction of the thigh you need something similar to Pongo
>(shallow acetabulum, etc.)
Not completely correct: Pongo's hip is extremely mobile in +- all
directions.
The australopithecine lateral alae & the long & horizontal femoral neck
facilitate abduction.
>There is no better explanation than that these features functioned in
>balancing the torso over the hips during bipedalism.
Balancing system??? ridiculous!
How could a broad pelvis balance the torso over the hips during bipedalism?
Broad pelvises are, of course, unstable in bipedal locomotion (cf. human
female vs male gait).
The small australopithecine hips give not enough support for full
bipedalism.
(Both these features could fit swimming. Broad pelvises don't seem to fit
wading. Small hip articulations could fit wading, swimming, quadrupedality,
climbing..., but are not adapted to our full bipedality.)
>There's no indication whatsoever that these features are aquatic
>adaptations (though they do not prohibit wading).
There's is no indication whatsoever that these features were not aquatic
adaptations.
(IMO australopiths: swimming, wading, climbing)
>Most mammals that enter the water use a modified form of terrestrial
>gait (i.e. parasaggital paddling), without abduction of the thigh.
>(Thewissen, J.G.M. & Fish, F.E.1997. Locomotor evolution in the
>earliest cetaceans: functional model, modern analogues, and
>paleontological evidence. Paleobiology 23: 482-490)
See C de Muizon 1995 An aquatic sloth from the Pliocene of Peru. Nat.375:224
Australopiths evolved from arboreal creatrues & were still semi-arboreal -
unique locomotion cf.CE.Oxnard (eg, different from Homo & different from
Afr.apes)
>>>Synapomorphies of Australopithecus and Homo:
>
>>Or what is traditionally called synapomorphies, if it's assumed that apes
>>represent the ancestral state. This of course is not true.
>
>Then, what method do you use to polarize the characters?
>On the basis of outgroup comparison there's little doubt that large
>projecting canines are plesiomorphic, as are small brains, long arms,
>long ilia, absence of lumbar lordosis, etc.
Outgroup Homo-Pan: 1) gorilla, 2) orang, 3) hylobatids, 4) OW monkeys
Absence of lumbar lordosis & "small" brains, okay: little doubt.
Projecting canines, possibly (ramapiths, eg, were once called hominid
because of their small canines)
But the very long ape arms are probably derived (& developed in parallel in
the different ape species IMO, see discussion in Verhaegen 1994
Hum.Evol.9:121):
- the most aberrant features (eg, leg length in humans) are usu. derived
- humans & monkeys have rel.long, but not very long (orang>chimp>gorilla)
arms
- rel.arm length gibbon&orang>chimp>gorilla>human (eg, gorilla rel.arm
length is nearer to humans than to orangs, so if we take the mean of
chimp/gorilla/man, the hominid LCA did not have "very" long arms)
- long arms in the fossil hominid record appeared late:
- gorilla length in boisei ER-739, OH-36, L-40-19
- OH-62>>Lucy (Lucy had rel."short" arms & legs, as you know)
Long ape ilia (ie, not "elongated", but "long relative to torso length") are
no doubt derived:
- humans & monkeys have "short" ilia - see Schultz' comparisons & figures
- WL Straus: "the anthropoid-ape type of ilium is in no sense intermediate
between the human & lower mammalian forms"
- see discussion Verhaegen 1994 Hum.Evol.9:121
>>Flipperlike (long metatarsals & short digits) = swimming feet:
>>in sealions > humans > australopiths > Afr.apes
>
>Metatarsals and phalanges in humans and australopithecines relatively
>shorter than in non-aquatic Afr.apes.
Okay for phalanges.
"Long, flat, broad feet with robust first & last digital rays are typical of
wading, swimming & diving birds & mammals (fig.5.5) but terrestrial &
arboreal animals have narrower feet with the central digits being those most
emphasised (Wyss 1988) ... in modern man, the common integumentary covering
of the foot encloses a much higher percentage of the toe bones than in any
extant primate" (Verhaegen 1991 in Roede ed."Aq.ape..." Souvenir). IOW the
human short toes enhance the closed plantar surface. Cursorials, on the
contrary, have elongated toes.
>
>>Full plantigrady is seen, eg, in humans & Afr.apes & australopiths &
sealions.
>
>Yes, plantigrady was probably already present in the bear-like
>terrestrial ancestor of Pinnipedimorpha and has nothing to do with
>aquaticness.
Why do you think this bearlike pinnipedimorph ancestor was "terrestrial"?
>>Univertebral articular pattern for the first rib.
>
>>Instead of bivert.articulation. Chimps are intermediary.
>>Discussed in Verhaegen 1991
>>(loose rib articulations are seen in most aquatic mammals)
>
>Whales have single-headed ribs, but this situation is not even
>remotely present in hominins.
Of course (cetaceans!), but loose rib articulations as in aquatic mammals
could easily be due to the water support.
>>Primitive arm in australopiths, not yet knuckle-walking.
>>(first K-W features are seen in boisei arm bones)
>
>And those incipient K-W features are?
Robusticity, length, curvature, & cross-section of arm bones (refs in
Verhaegen 1994 Hum.Evol.9:121)
Etcetera etcetera.
(such sterile discussions are a waste of time)
Jim McGinn
Norman K. McPhail wrote in message <356DD0...@socal.wanet.com>...
>Jim McGinn wrote:
>>
>> Norman K. McPhail wrote in message <356C9B...@socal.wanet.com>...
>> >Paul Crowley wrote:
>> >>
>> >> On Tue, 26 May 1998 16:52:51 -0700, "Jim McGinn"
>> >> <jimm...@msn.com> wrote:
>> >>
>> >> >>Paul Crowley heeft geschreven in bericht
>> >
>> >>
>Jim wrote:
>>
>> Boy have you gotten the wrong impression from my previous post. I am the
>> most deterministic, reductionistic, and mechanistic (in addition to being
>> relativistic as opposed to being absolutistic) scientist that I know.
>
>This is the second time this year I've been wrong. And boy was I wrong.
>How did I get such a wrong impression? Perhaps because as you say, you
>are relativistic? Regardless, I still found a lot that rang true in the
>post you refer to.
>
It is insightful on your part that you keyed in on my relativistic aspects
to my approach. This is the one area where I differentiate my thinking from
that of traditional evolutionary biologists, ie. Dawkins. Dawkins work,
which pretty much reflects the current paradigm, is chock-full of
absolutistic assumptions. It is these absolutistic assumptions that--when
combined with reductionism, mechanism, and determinism--are the source of
the anti-human aspects of evolutionary theory. The problem is not
reductionism, mechanism, and determinism in themselves. (I can prove this.)
>
>> I'm
>> an extremist on this point. I don't allow for any kind of thinking that
in
>> any way resembles vitalism. I don't even allow for the existence of
>> stochastic processes (ie. genetic drift) as a causal factor.
>
>How do you stand on the idea of sexual selection
I see sexual selection as being sub-operative to natural selection.
and fitness selection?
When fitness is properly defined I have no trouble with it. But I have yet
to see fitness properly defined. Invariably the definitions I have seen
contain some greater or lesser absolutistic assumption(s). I have redefined
fitness but I first had to redefine a lot of the underying terminology. In
other words, if I was to state it to you right now you wouldn't have a clue
what I was talking about. So I won't open that can of worms.
>Do you think there is room for selection that is related to things other
>than pure deterministic fitness?
No. (Again, assuming fitness is defined properly.)
>
>Moreover I
>> find reading S.J. Gould to be very frustrating because he opens the door
to
>> this kind of nonscientific thinking.
>>
>> I breezed through your website. It has nice pictures but it isn't
>> scientific.
>
>I agree, it's not scientific in the narrow sense I assume you use and
>define the term. In fact, I go to lengths to say where I think what we
>normally call science is useful and where I think it causes a lot of
>grief.
I agree science does cause a lot of grief. And more than any other science
evolutionary theory, especially when it involves human origins, is the
source of grief. I am a strong proponent of selective censorship of human
evolutionary theory. No kidding. In fact when the cause of human evolution
is finally revealed. (And theis will happen very soon, take my word on it.)
It will be made clear why it is that evolutionary theory (especially as it
applies to implications on traditional beliefs of human origins--both
secular and religious) is such a source of grief.
>This is one of the main points of the proposed documentary TV
>series.
>
>To repeat, the site is a treatment for this proposed TV series, nothing
>more or less. I never claimed to be a scientist. And it's not
>surprising that the contents are looked down on by most scientists.
>
This is a scientific newsgroup.
>Since I've also never written a script or a treatment before, it's not
>surprising that the contents don't pass muster from the TV
>specialists/professionals either. In fact, you would not be too far
>afield if you made the blanket statement that lots of people find the
>site trivial speculation. What would you expect from someone with no
>academic credentials to speak of and no experience in the field of
>documentary film production.
>
>I will wholeheartedly agree with all of the above. In fact, I take
>great pains to point all this out in the preface and elsewhere. So I've
>tried to make all this as clear as I can to those who visit the site.
>
The fact that I don't find the site scientifically valid should not in any
way be the measure of the value of the site. I also think it's a beautiful
and well constructed site.
>
>> I read two books on the "Science" of complexity, one by Waldrop and the
>> other by Lewin. As I see it Complexity is little more than the restating
of
>> what we already know using non-linear mathematics. To the extent that
the
>> Science of Complexity stays within those boundaries it is useful.
>> Unfortunately the proponents of Complexity have a tendency to proclaim it
to
>> be more than it really is. There critics sometimes refer to it,
>> sarcastically, as, "a fact free science."
>
>You might be interested to learn that I think complexity theory is less
>than sound too.
>
>> I have found complexity theory useful for helping us understand the
>> boundary conditions by which life might have first come about on this
>> planet.
>
>Do you think that some form of altermative thought mode might also be
>useful in understanding the margins between life and thought? Or do you
>reduce these to the same thing?
When I'm wearing the hat of a scientist the answers to these questions are,
no to the first and yes to the second.. Otherwise (and usually) the
answers are yes to the first and no to the second.
It will tell us the how and why. (This I know because I will be the one who
does it.) As to the what, however, and the details thereof, well, most of
that has been lost in time.
>
>Where I think we disagree is that I say that unless science changes some
>of it's basic assumptions and thought modes, it will never be able to
>explain all of what I am calling human understanding. In fact, I think
>science can only hope to explain about half the truth when it comes to
>human understanding. This is one of my main points.
I agree with you with respect to the basic assumptions, ie absolutism.
Marc Verhaegen
Paul Crowley heeft geschreven in bericht
<356d7a7a...@news.indigo.ie>...
>On Wed, 27 May 1998 03:29:46 +0200, "Marc Verhaegen"
>>Why do you think the australopith habitat was not suitable for
>>fossilisation?
>
>I maintain that the hominid (normal definition) habitat for the
>last 5 Myr has been the littoral. It's where, broadly speaking,
>they concentrate today. Littorals are poor places for
>fossilization. There absorb enormous amounts of energy and sea
>levels are constantly rising and falling, destroying the
>evidence. The obvious way for a littoral population to expand
>is to go inland. And almost every generation would export its
>surplus young in that direction. Generally they would finish up
>beside some lake or water hole, possibly buried in a shallow
>grave by their companions, sometimes suffering from the effects
>of vitamin-A poisoning after eating their dogs. This is the only
>reasonable account for the condition of my favorite fossil KNM-ER
>1808. Another vitamin-A-poisoned fossil was found at Venosa in
>Italy dated to about 0.5 mya.
No evidence of vit.A poisoning in hominid fossils! This solution was
"invented" because they could find any better.
(The thick bones can only be explained by slow diving.)
Littorals, okay, but diving littorals.
>>>>Apes need their large canines for opening fruits... The males also for
>>>>intraspecific use.
>>>
>>>The opening fruit use for large canines is fairly minor.
>>
>>Nonsense, the dietary use for canines is the canine size you see in
females
>>(opening fruits, eating bark from trees...
>>
>>> All primates, other than us, have large canines. Many have little
>>>dietary application (e.g. male gorillas or male gibbons).
>>
>>Nonsense.
>
>Large canines are expensive.
Are they?
> The hominid (n.d.) line lost theirs
>quite quickly at the earliest opportunity. Rather than say "nonsense"
Why should teeth have little dietary application?? (I don't say they can't
have other functions too.)
> you need to explain why all primates, other than us,
>possess them, considering they have an enormous range of diets.
Gigantopith. had small canines. Somo Sivapith. "ramapiths" had small
canines. Hapalemur (bamboo lemur) has small canines (not much longer than
its incisors & much shorter than Lemur). Some believe Gigantopith. ate a lot
of bamboo.
>You also have to explain why males generally have much larger ones than
females.
I don't have to explain. It has been explained: intraspecific adaptations.
> Males and females of the same species usually
>have the same diet. Male gorillas have enormous canines. They
>eat much the same as females.
The female teeth are almost exclusively dietary, the male/female difference
can be regarded as predom.not-dietary. Gorillas are polygynous.
>Once an animal has such expensive equipment it will, of course,
>use it for as many purposes as possible. Male chimps use them to
>kill prey. But they don't have to. Goodall reports that Evered
>lost three of his four canines in old age, but was still a
>skilled hunter. He developed a technique of swinging the body of
>the prey aninal against a tree trunk to kill it.
Beautiful!
>>> Thirdly, there is no clear way
>>>that a animal with large canines could adapt to diet that
>>>required a horizontal (cow-like) motion of the jaws. That motion
>>>only becomes possible once the large canines have gone; so there
>>>is no mechanism that could enable a gradual reduction.
>>
>>No. Simplification.
>
>How is it a simplification? The interlocking nature of the large
>canines of all our close relatives prevents horizontal motion
>with closed or near-closed jaws.
Not totally. Tragulids, eg, have long canines.
>How does such an animal switch to the cow-like (or human-like) rotary
motion? IMO it is quite clear that the canines have to be reduced in size
for quite different reasons _first_.
I don't think so. Canine loss seems to be one of the latest steps
(dentition) in becoming a herbivore.
>>>Fourthly, once an animal had adapted to such a diet, there is no way that
large canines could come back (as you assert vis-a-vis gorillas).
>>
>>Why not? The canines were "small", but did not disappear.
>
>Imagine us re-growing large canines! We would _first_ have to change our
method of mastication. Why on earth would we?
The australopiths (very clear in africanus) still had buttressed maxillae
for the canines.
>>(I didn't assert, but I do think it possible that gorillas have regrown
larger canines.)
>
>If gorillas are descended from australopiths...
I did not say that. I said that IMO boisei was in the gorilla clade
(possibly an extinct sidebrach, possibly a more direct ancestor).
>>>Fifthly, you can point to no parallels among any
>>>other large-bodied (or even small-bodied) mammalian taxa of such
>>>rapid changes in diet and morphology.
>>
>>Rapid?? See previous messages.
>
>As you well know, changes in dentition are extraordinarily slow
>in all taxa. They are distinctive to orders, families and
>genera. Your disregard of the permanence of their nature is
>cavalier.
("cavalier"? horse-rider?)
See the difference between the Sivapith. species: some with "long", some
with "short" canines.
I for myself have on my left side "sharp" canines, on my right side flatly
worn ones.
A.afarensis had "long" canines, africanus intermediary, boisei & robustus
short ones.
>>>>> They'd have had to stand still in a group, using stones and clubs to
keep the predators (or enemy hominids) at bay.
>>
>>Do tapirs use clubs to keep predators or enemy tapirs at bay?
>
>I don't get your analogy. Primates (and especially us and
>chimps) are social animals that aggressively attack neighbouring
>groups. Tapirs are solitary animals, that don't have the
>equipment for this activity anyway.
So what? Both fighting or not-fighting tapirs/chimps/humans are the same.
> Tapirs use speed (in the context of their habitat) to escape predators.
Exactly. I think that's what australopiths mostly did.
> They also have sharp teeth and fight viciously when cornered.
No long canines in tapirs.
>>>Why improbable for the australopiths? Chimps are nearly there;
>>>it is not IMO at all hard to see a chimp population that moved to
>>>more open ground adopting such habits.
>>
>>The hominid physiology is not suited for open & dry milieus.
>
>I didn't say anything about open and dry milieu. I meant
>"slightly more open than chimp habitat" i.e. not too many trees
>to get in the way of swinging clubs, possibly a beach.
There they could flee into the water (or flee to the land when in the
water).
>
>
>>>Australopiths in trees would be much more vulnerable than baboons.
>>
>>Why??
>>(and A.boisei males were 3-4 times as large as baboons)
>
>Being bipedal, australopiths would be far less capable in trees.
No, proboscis monkeys are extremely agile in the trees, yet they are bipedal
in the water & sometimes on land.
Lucy had clear arboreal adaptations (eg, curved pahlanges of hands & feet),
no doubt "she" was very agile in the trees.
>And they don't have the other baboon adaptations to trees, such as the
iscial calosities.
How do you know the australopiths had no ischial callosities?
> Being heavier, they would not be able to get to the higher, smaller
branches.
Lucy was probably 20-30 kg. The boisei male was perhaps 80 kg or more.
> So size is a
>disadvantage. Recent infra-red films of leopards hunting baboons
>shows that the baboons are effectively blind at night, whereas
>leopards can see. The leopard doesn't always use subterfuge. It
>lets the baboons know it's there, and panics them into error.
>
>
>
>>(& can't you read? It was no problem in the water (cf. diving Fuegian
women)
>
>Sorry I had no idea that you believed hominids spent all their time in the
water.
Well, even that is not completely impossible. Childbirth is easier in the
water than outside (Michel Odent). Some waterborn babies sleep the whole
night floating on the water & even cry when taken out.
>>>I accept that stones and clubs must be carried. This would have
>>>been a very important motivation for bipedalism.
>>
>>It's the other way round of course: carrying a club was possible because
>>Homo was bipedal. And he was bipedal because his diving/wading past had
>>forced him into this (slow & costly) posture.
>
>I accept the now common view that the chimp (5 mya) was our ancestor.
The were no "chimps" 5 mya. There was the LCA of chimps & humans then. The
best approximation of this creature we have today is africanus or Lucy:
bipedally wading, arboreal, swimming.
>You may go for another CA.
What is CA?
> In any case it was probably using clubs much as chimps do today.
I don't think so. They were already partial waders.
> This use needs a kind of
>bipedalism. All you have to do is provide an environment that
>encourage that and you have bipedalism in males. (Females are,
>of course, another story).
??
>>>>We see a relative canine reduction from graciles to
>>>>robusts, just as expected from their diet. I can't see any problem for
>>>>explaining the australopith canines.
>
>>Unique??? See tragulids & cervid
>
>When did they lose their canines?
Somewhere between tragulid/cervid canines were lost.
>>>>& bonobos "have rel.smal & only slightly projecting canine teeth"
>>>
>>>What is your source for this? Does it apply to males?
>>
>>Zihlman etc.1978 Nat.275:744
>
>Zihlman in 1978 about Bonobos, is about the worst sort of
>reference possible. The famous Kanzi is a bonobo; there is
>nothing small, or "non-projecting" about his canines.
Is Kanzi a male?
Marc
Gerrit Hanenburg
Marc Verhaegen <Marc.Ve...@village.uunet.be> wrote:
>Okay, but there is "typical" & "typical". What is really typical in humans
>is, eg, the extreme brain size & leg length - absent in monkeys,
>australopiths & all apes (including bonobos & immature apes).
When such highly derived features become the criteria for being
"typically" human then it is no wonder that hominins that are still
close to the ancestral state do not show anything "typically" human.
>>There is no better explanation than that these features functioned in
>>balancing the torso over the hips during bipedalism.
>Balancing system??? ridiculous!
>How could a broad pelvis balance the torso over the hips during bipedalism?
By contraction of the laterally positioned M. gluteus medius and
minimus, as in modern humans. (See Rak, Y. 1991. Lucy's Pelvic
Anatomy: It's Role In Bipedal Gait. JHE 20: 283-290, for a functional
interpretation of Lucy's relatively wide pelvis)
>Broad pelvises are, of course, unstable in bipedal locomotion (cf. human
>female vs male gait).
>The small australopithecine hips give not enough support for full
>bipedalism.
Although it's true that Lucy's femoral head is relatively small
compared to modern humans, that doesn't imply that it couldn't carry
the weight of her torso during bipedal locomotion.
Or perhaps you have quantitative data that her hip would have
fractured?
The biomechanical advantage of australopithecine lower limb and pelvic
morphology during bipedalism, relative to that of non-hominins, have
been discussed at length in the literature.
There is virtually consensus with regard to that point among those who
have studied the material from that point of view (though there is
still discussion with regard to the exact form and the relative degree
of australopithecine bipedalism).
Australopithecines were probably not fully bipedal and their
bipedalism was probably not as efficient as that of modern humans, but
the point is whether or not it was effective under given ecological
circumstances (and that may even include wading in swamp grassland,
but not necessarily or primarily. After all, wading is only one
"application" of bipedalism).
>But the very long ape arms are probably derived (& developed in parallel in
>the different ape species IMO, see discussion in Verhaegen 1994
>Hum.Evol.9:121):
>- the most aberrant features (eg, leg length in humans) are usu. derived
>- humans & monkeys have rel.long, but not very long (orang>chimp>gorilla)
>arms
>- rel.arm length gibbon&orang>chimp>gorilla>human (eg, gorilla rel.arm
>length is nearer to humans than to orangs, so if we take the mean of
>chimp/gorilla/man, the hominid LCA did not have "very" long arms)
>- long arms in the fossil hominid record appeared late:
> - gorilla length in boisei ER-739, OH-36, L-40-19
Absolutely or relatively?
> - OH-62>>Lucy (Lucy had rel."short" arms & legs, as you know)
Humerofemoral index in OH 62 is 95%, but as you know this specimen is
very fragmentary, so there may be a considerable error.
(Johanson et al. 1987 do not give confidence limits of their
estimate).
A.afarensis DID have relatively long arms, mainly due to a relatively
long forearm (Kimbel et al. 1994. The First Skull and Other New
Discoveries of Australopithecus afarensis at Hadar, Ethopia. Nature
368: 450).
>Long ape ilia (ie, not "elongated", but "long relative to torso length") are
>no doubt derived:
>- humans & monkeys have "short" ilia - see Schultz' comparisons & figures
>- WL Straus: "the anthropoid-ape type of ilium is in no sense intermediate
>between the human & lower mammalian forms"
>- see discussion Verhaegen 1994 Hum.Evol.9:121
Try a different measure of relative length (e.g. relative to femoral
head diameter).
>>Yes, plantigrady was probably already present in the bear-like
>>terrestrial ancestor of Pinnipedimorpha and has nothing to do with
>>aquaticness.
>Why do you think this bearlike pinnipedimorph ancestor was "terrestrial"?
On the basis of anatomy and phylogenetic inference.
Pinniped anatomy is basically that of a quadrupedal mammal that, like
cetaceans, became secondarily aquatic.
Phylogeny: Ursidae is the sistertaxon of Pinnipedia. Procyonidae is
the sistertaxon of Ursida (= Ursidae + Pinnipedia).
Both Ursidae and Procyonidae are characterized by plantigrade
quadrupedal terrestrial locomotion. Therefore it is most likely that
this is the ancestral state.
>>Whales have single-headed ribs, but this situation is not even
>>remotely present in hominins.
>Of course (cetaceans!), but loose rib articulations as in aquatic mammals
>could easily be due to the water support.
You should specify what you mean by "loose rib articulations".
All primates have the primitive double articulation between ribs
(caput costae and tuberculum costae) and vertebrae. Hominins are no
exception.
>>And those incipient K-W features are?
>Robusticity, length, curvature, & cross-section of arm bones (refs in
>Verhaegen 1994 Hum.Evol.9:121)
Is that it? Can't you provide us with a little less ambiguous
evidence?
Every undergraduate who studied chapter 17 and 18 in Aiello and Dean's
"An Introduction to Human Evolutionary Anatomy" knows better.
(For example: Paranthropus doesn't have an incipient deep olecranon
fossa with steep and sharp lateral margin. See p.367 in Aiello and
Dean)
>Etcetera etcetera.
>(such sterile discussions are a waste of time)
Sure, unlimited speculation is much more fun.
Gerrit
Norman K. McPhail
Jim McGinn wrote:
>
> Norman K. McPhail wrote in message <356DD0...@socal.wanet.com>...
> >Jim McGinn wrote:
> >>
> >> Norman K. McPhail wrote in message <356C9B...@socal.wanet.com>...
> >> >Paul Crowley wrote:
> >> >>
> >> >> On Tue, 26 May 1998 16:52:51 -0700, "Jim McGinn"
> >> >> <jimm...@msn.com> wrote:
> >> >>
> >> >> >>Paul Crowley heeft geschreven in bericht
> >> >
> >> >>
> >Jim wrote:
> >>
> It is insightful on your part that you keyed in on my relativistic aspects
> to my approach. This is the one area where I differentiate my thinking from
> that of traditional evolutionary biologists, ie. Dawkins. Dawkins work,
> which pretty much reflects the current paradigm, is chock-full of
> absolutistic assumptions. It is these absolutistic assumptions that--when
> combined with reductionism, mechanism, and determinism--are the source of
> the anti-human aspects of evolutionary theory. The problem is not
> reductionism, mechanism, and determinism in themselves. (I can prove this.)
You seem to be describing the same aspect of scientific thought and
assumptions that I think causes a blind spot. But I also think all of
us have a hard time seeing through this blind spot. So in some
respects, we are all handicapped with this blind spot. And I would
point to the evolution versus creation debates as evidence of how
pervasive this problem is.
> >
> >> I'm
> >> an extremist on this point. I don't allow for any kind of thinking that
> in
> >> any way resembles vitalism.
Vitalism, to my way of thinking, is just another way of saying we don't
know what life is or how it got started. We do this with a lot of
things that seem too big to grasp. It may be that it causes too much
stress for most people to keep working on a big problem like this.
So we often point to some notion that has no meaning and try to fool
ourselves into believing that we have it all figured out. The big
problem with quick fix notions like vitalism is that we give up trying
to understand what things like life are. And so long as we give up
trying to understand something like life, there is a 100 percent chance
that we won't figure it out.
> >>I don't even allow for the existence of
> >> stochastic processes (ie. genetic drift) as a causal factor.
> >
> >How do you stand on the idea of sexual selection?...
>
> I see sexual selection as being sub-operative to natural selection.
>
> >and fitness selection?
>
> When fitness is properly defined I have no trouble with it. But I have yet
> to see fitness properly defined. Invariably the definitions I have seen
> contain some greater or lesser absolutistic assumption(s). I have redefined
> fitness but I first had to redefine a lot of the underying terminology. In
> other words, if I was to state it to you right now you wouldn't have a clue
> what I was talking about. So I won't open that can of worms.
I'm going to guess that your notion of fitness may not be too different
from mine. So please spell it out and lets see how far apart we are.
> >Do you think there is room for selection that is related to things other
> >than pure deterministic fitness?
>
> No. (Again, assuming fitness is defined properly.)
> >>
> >> I breezed through your website. It has nice pictures but it isn't
> >> scientific.
> >
> >I agree, it's not scientific in the narrow sense I assume you use and
> >define the term. In fact, I go to lengths to say where I think what we
> >normally call science is useful and where I think it causes a lot of
> >grief.
>
> I agree science does cause a lot of grief. And more than any other science
> evolutionary theory, especially when it involves human origins, is the
> source of grief. I am a strong proponent of selective censorship of human
> evolutionary theory. No kidding. In fact when the cause of human evolution
> is finally revealed. (And theis will happen very soon, take my word on it.)
> It will be made clear why it is that evolutionary theory (especially as it
> applies to implications on traditional beliefs of human origins--both
> secular and religious) is such a source of grief.
>
What follows is why I think it's important to reconcile evolutionary
theory with our secular and religious values:
The Value of Life.
The misuse of metaphors by science is not new. Newton's clockwork model
tries to reduce all realms to a physical cause and effect world. This
still mixes up how we think life works three hundred plus years down the
line.
In biology, some have tried to reduce the way life forms evolve to a
single phrase. Thus, many think that the "survival of the fit" is how
life got to be the way it is. This meme, like many others we think came
from science, has crept into our culture and value systems.
But most scientists I know think it's wrong to try to improve our
species by culling the unfit. And like most of us, they say we ought
not to value others by how fit they are. In other words, how we value
each other ought not to be based on any fitness test. Then they say we
shouldn't base our human values on the laws and theories that science
gives us.
By this, scientists mean that we shouldn't derive moral or social values
from what science finds in nature. They claim that the rules we agree
to live by are not like the rules that govern nature. Thus they suggest
that the laws of nature and those we make up are not in the same
class.
But I say that these rules we make for ourselves are almost always based
on the values we hold. And I think most people would agree that our
values are a big part of our rules and laws. If a law is out of sync
with our values, most people will not comply with it.
Most of us who've been in law enforcement know that most of the job is
getting people to comply. Yet over the long haul, the laws that are out
of sync with our values just don't work well. So it's like the old
saying says, you can't legislate morality.
What's more, I claim that we use the lessons that science teaches us to
change our values. Then these values show up in the laws and rules we
set up for our selves. Our environmental and abortion laws are two good
examples of this.
Most of us now grasp the fact that we humans have bent some of the laws
of nature. Natural selection does not work the way it used to. Today,
we have a lot to say about which species live and which ones die. We've
learned to bend some of the laws of nature for our own benefit.
Science has shown us how to protect and extend our lives. It has helped
us produce enough food to feed vast numbers of our kind who would starve
without it. Then we shape our environment and ecosystems to make life
safe and easy.
To do all these things, we've had to change the rules of survival for
most species on this earth. Science has helped us grasp this fact. And
it has helped us see how we have hurt our habitat.
So most of us now understand that we pay a big price to protect and feed
our selves. True, we still place a high value on human life. But now
we realize that too many people can deplete the earth's resources.
When we're not careful, we degrade the ecosystems we all depend on. And
we now know that at the very least, this will reduce the quality of
human life. Thus it's easy to see that science has had a role in
changing some of our values.
Then science found new ways to control birth. And this helped bring
about more changes in how we look at and value human life. Hence, some
of our values are not the same as those of our parents and grandparents.
Next, these kinds of changes in values led to changes in our laws about
abortion. We also wrote laws to help us clean up and restore our
environment. Then we passed laws to help save species that are at risk
of dying out. We derived all these laws from what science has taught us
about life, ecosystems and the biosphere.
We now can see that we are just a part of this biosphere. So our values
reflect these insights into how all life systems interact and depend on
each other. And now our laws also reflect at least some of these new
values.
But what about a meme like the survival of the fit? What does it mean
when scientists conclude that the weak will die off? To me, this
implies that in the wild the genes of an unfit plant or animal will also
die.
But then science says this harsh rule of nature promotes the fitness of
the species as a whole. And this fitness, in turn, may keep it from
going extinct. So in the long run, science concludes the survival of
the fit can benefit living things.
Next, most people will wonder if the health of our own kind isn't
governed by this law of nature. We all know that we humans are just a
form of life. So it makes sense to ask whether we should value each
other based on how fit we are.
From the late 1800s through the first half of this century, people from
around the world asked this question. As a result, lots of people felt
that the unfit should not have children. It was called eugenics. And
it was wide spread.
Then the Nazis took this meme to a new level. They said the unfit
polluted the gene pool. And they killed millions whom they thus judged
as not fit to live.
There are a few that still think this way. They say we should cull out
the weak unfit amongst us. They claim that this is for the good of the
species.
Yet we've seen that even though our forebears were adaptable, they were
not what we might call fit. But recall that it was this lack of fitness
that helped them change their problems. They changed their gene
changing problems into thought problems. This led to a four fold
increase in brain size and what we now call thought.
We saw that our forebears were good at living in the seams between
habitats. There is now some evidence that they felt at home in places
like a beach. Here they could go back and forth between the land and
the sea. They also liked to hang out in the trees that ran between the
rain forest and the plains. And they may have gone back and forth
between many of these places including the mountains and the desert.
Yet in spite of all this, our forebears were not well suited to any one
habitat. So they paid a big price for being adaptable. The price was
that they did not fit well into any one habitat.
We've seen that this is different from the way most species evolve.
Most species evolve to fit into a tight niche in an ecosystem. Yet when
we compare this with our forebears' game plan, it's easy to see what
misfits they were.
Their odd mix of features were not a good match for any one place.
Their traits were only partly suited to the jungle, the sea, the plains,
the desert or the mountains. So they didn't fit in anywhere.
They were not very fast. They were not very strong. They were not very
big. They were not very good swimmers. They couldn't fly. They had no
claws. They had no protective shell or fur. And they had no fangs.
Still, our forebears had lots of choices. They could go where the trees
were ripe with fruit. They could dig for tubers and fish for termites.
They sometimes hunted small rodents and monkeys. They could scavenge
the marrow and brains when the big cats and dogs were done with their
kills. They could dine on leaves, nuts and fruit from high in the trees
or veggies on the ground. And they could harvest a wide assortment of
sea life near the shore.
What's more, our forebears found that the margins between habitats gave
them lots of ways to play it safe. Here they had lots of choices. At
times, they could just jump in the water to escape from a predator. At
other times, they might climb into the trees to stay out of harm's way.
If sharks got too close while they were diving for urchins, they could
just run up on the beach.
But they had to learn how to exploit the safety and shelter of many
habitats. And they also had to learn when, where and how to exploit a
given habitat for food.
With all these choices, our forebears came to rely more and more on
their brains. Still, they didn't physically fit any one of these
habitats very well. In fact, it's no stretch at all to say that they
were physically unfit.
So I like to say that our forebears were misfits. Yet I think this lack
of fitness meant that they had to be able to make wise choices. And
this, in turn, meant that to survive they had to depend more and more on
their brains.
It was their bodies that could not keep up with all the changes. Their
genes could not change their bodies fast enough to adapt to all the
changes going on around them. So they had to find another way to
survive.
If they were going to survive, our forebears had no choice. They had to
rely on their brains and their mental fitness. Thus, I think we got our
big brains at least in part because our forebears were not physically
fit.
Now we come to why I think it's a mistake to blur the notion of physical
and mental fitness. What happens if we merge our forebears' fitness to
mean both their physical and mental fitness? We miss the way these two
types of fitness work with each other. Hence, we miss a big part of how
and why a long string of complex changes led to understanding.
Understanding the details of how we got to be the way we are, tells us a
lot about ourselves. For one thing, it helps us see how we differ from
other species. And this, in turn, helps us grasp why we place such a
high value on human life.
So this is why it's important to understand how and why we got to be the
way we are. This true story helps us understand why it's wrong to take
a human life. And this, in part, is why most of us now agree about the
high value of human life. Thus, when it comes to the value of a human
life, most of us say fitness just isn't relevant.
Still, some persist and argue that promoting the survival of the fit
would help our species as a whole. They might try to convince us that
it's good to sterilize or kill off those who are not fit. And they
might try to pass laws that allow the strong to get away with killing
off the weak. We can all name far too many examples to prove that this
meme is still alive if not thriving throughout the world.
But science gives us yet one more reason to value any and all human
life. And this reason, in turn, helps explain why we pass and enforce
laws against killing each other. This reason has to do with gene
diversity.
One thing we know for sure is that our descendants will face a wide
range of crises. Sharp ice age climate changes will threaten their food
supplies. Our species will be under pressure from new and changing
virus strains. And it will face a whole host of disasters like the
meteor that caused the death of the dinosaurs.
Yet the biggest risk of all may be the threat we pose to our selves. In
the next world war, we'll use nuclear, chemical and biological weapons
to kill billions of our own kind.
A diverse gene pool may help ensure that at least some of our species
will live through these crises. The point is that it makes sense to
protect and promote a diverse human gene pool. One of the ways we can
do this is by valuing the lives of all our fellow human beings.
Once again, we've seen that a diverse gene pool helps a species survive
over the long haul. And we've seen that it was the fact that our
forebears were unfit that led to their big brains. In the light of
these two facts, the high value we place on each person makes more
sense. Thus what we learn through science seems to confirm the value of
human rights, ethics and high moral standards.
This, in turn, prompts us to pass laws that make it wrong to kill each
other. World wide, we are seeing more and more people who are able to
declare and protect their human rights. We're even starting to outlaw
genocide and other crimes against our own kind.
So a closer look at nature can lead us to a much different set of
values. From all this, it should now be clear that what we learn from
science influences and changes our values. And these value changes, in
turn, can and do have a big impact on our rules and laws. Values can
lead to big changes in the laws and rules we use to govern our selves.
So whether we like it or not, we use what we learn from science to help
govern our selves. All this is why we need to be so careful with the
theories and ideas that come from science. To me, this means that we
need to pay close attention to the hypotheses that science comes up
with.
The point is that there are strong ties between our laws, our values and
what we're learning. Once we recognize these ties, we can integrate
what science teaches us with our value systems. Then, perhaps, we can
do a better job setting up the rules we use to govern our selves.
Marc Verhaegen
Gerrit Hanenburg
...
>Australopithecines were probably not fully bipedal and their
>bipedalism was probably not as efficient as that of modern humans, but
>the point is whether or not it was effective under given ecological
>circumstances (and that may even include wading in swamp grassland,
>but not necessarily or primarily. After all, wading is only one
>"application" of bipedalism).
Okay, but wading fits the microwear data of PF Puech.
>> - gorilla length in boisei ER-739, OH-36, L-40-19
>Absolutely or relatively?
Absolutely
>> - OH-62>>Lucy (Lucy had rel."short" arms & legs, as you know)
>
>Humerofemoral index in OH 62 is 95%, but as you know this specimen is
>very fragmentary, so there may be a considerable error.
>(Johanson et al. 1987 do not give confidence limits of their
>estimate).
"may be" - Why always choosing the less probable explanations?? why not just
considering the logical conclusion - just considering, just try - that
australopiths were evolving in the Afr.ape direction??
...
>A.afarensis DID have relatively long arms, mainly due to a relatively
>long forearm (Kimbel et al. 1994. The First Skull and Other New
>Discoveries of Australopithecus afarensis at Hadar, Ethopia. Nature
>368: 450).
Lucy did not belong to "afarensis" s.s. (Ferguson: "antiquus")
>>Why do you think this bearlike pinnipedimorph ancestor was "terrestrial"?
>On the basis of anatomy and phylogenetic inference.
>Pinniped anatomy is basically that of a quadrupedal mammal that, like
>cetaceans, became secondarily aquatic.
>Phylogeny: Ursidae is the sistertaxon of Pinnipedia. Procyonidae is
>the sistertaxon of Ursida (= Ursidae + Pinnipedia).
>Both Ursidae and Procyonidae are characterized by plantigrade
>quadrupedal terrestrial locomotion. Therefore it is most likely that
>this is the ancestral state.
Polar & other bears & racoons are semi-aquatic (IMO the ancestral state of
pinnipeds, bears & racoons)
Marc Verhaegen
Paul Crowley >Drox
>>> Most primates have large canines. The australopiths lost theirs.
>>> This *must* mean that they no longer needed them, which *must*
>>> mean that they had some other defence.
Robust australopiths lost their projecting canines (though they still showed
butressed maxillae for the canines). That means that projecting canines had
more disadvantages than advantages. The primary use of canines (at least in
females) is dietary. Projecting canines must have hindered chewing. This
fits the (almost) completely herbivorous diet of the robusts as shown by
their thick enamel, enamel microwear, huge (pre)molar & cheekbone size.
If you have projecting canines, you use them no doubt in defence, against
conspecifics or against predators.
I think we may assume that australopiths were about as strong & agile as,
say, chimpanzees. If the danger came from the water (crocodiles...) they
fleed to the trees (at least the graciles) or to the land (large canines
were of no use). If the danger came from the land (leopards...) they fleed
to the water or to the trees, where they were more agile than leopards. I
doubt if even the large boisei males strongly defended themselves & their
group mates. How do gorillas manage? I think you must not overemphasize the
worth of canines against leopards (the strong arms were probably more
important).
The use of canines against other males (display, attack, defence) is the
same in both fighters. If the dietary disadvantages of long canines
outweighted the intraspecific advantages, long canines gradually shrunk, &
vice versa. (If you starve though you can beat all other males, your long
canines are of no use.)
...
>Monkeys are preyed upon by chimps, baboons, eagles and leopards.
>Males do their best to defend females and infants, using their
>only weapons -- large canines. See the films of chimp hunts.
Of course, if you already possess large canines (for eating), you no doubt
use them also for defending yourselve.
(not the "only weapons": eg, arms, cf. chest-beating)
>
>>AFAIK the large canines
>>(found even in tree-dwelling primarily-herbivorous species) are not so
>>much for interspecies defense as for intraspecies intimidation-display
>>and occasional intraspecies fighting.
I too think that their intraspecies use (display, occasional fighting) is
more important than their use against predators. But IMO dietary use is
still the most important, no doubt in children & females. Partially
frugivorous herbivores usu. have projecting canines (eg, tragulids,
peccaries) but more complete herbivores have short canines (eg, tapirs,
capibaras).
(what is AFAIK?)
...
>The main changes were bipedalism, the acquisition of hands
>designed to grasp, and the loss of large canines. These fit far
>too well with club wielding for it not to be the main hypothesis.
In an evolutionary perspective I think you have to explain all features
independently.
- striding bipedalism in primates is always wading (& gibbons walking along
branches perhaps)
- grasping hands cf. monkeys & apes
- fine manipulation in Homo cf. racoons & otters (& in robusts cf. perhaps
bamboo bears)
- loss of projecting canines in australopiths esp. robusts: herbivorous
- in Homo (in Sangiran still "more powerful canine", Rensch 1972 "H.sapiens"
Columbia UP): use of stones instead of canines? (or problems for suction?)
Capuchin monkeys use stones, bones, sticks, but are not very much bipedal.
Otters & racoons are very dextrous (& otters often adopt a bipedal stance)
but don't use sticks.
In racoons, as in humans, the brain representation for the hands is many
times larger than that for the feet.
Capuchins, otters, racoons do have projecting canines.
Of course, if you are bipedal (wading history) & you have dextrous hands
(eg, mollusc opening history), there is no reason why should not use clubs.
Paul, I think you make the same mistake as the savanna people who want to
link bipedality & nakedness & transipiration etc.
Marc
Dwight E. Howell
> snip
> >The main changes were bipedalism, the acquisition of hands
> >designed to grasp, and the loss of large canines. These fit far
> >too well with club wielding for it not to be the main hypothesis.
>
> In an evolutionary perspective I think you have to explain all
> features
> independently.
> - striding bipedalism in primates is always wading (& gibbons walking
> along
> branches perhaps)
Please use more logic with what you say. If these organisms only walked
as bipeds when in water they would have had to spend all their time in
water or not become bipeds. It is reasonable to suspect that spending
time in water (wadding) caused more bipedal locomotion but if it was
completely restricted to such a location they would still be quadrupeds
(most likely) as are modern apes when out of water. Please also read
some modern research on chimp behavior and stop making blanket
statements. Many sources report bipedal locomotion for a huge variety of
reasons.
Yeah, I cut some stuff but one problem at a time.
Jim McGinn
Norman K. McPhail wrote in message <356F12...@socal.wanet.com>...
I agree that we have the blind spot, but I don't agree that it's a problem.
I see it as a survival mechanism.
Although it seems almost too ironic, once you understand what caused human
evolution you come to realize why it is that our species has evolved a
natural resistance to scientific based explanations of human origin--you
come to realize what is meant by the biblical advice that we not eat the
fruit from the tree of knowledge.
Human evolutionary theory is the ultimate Pandora's Box.
>
>> >
>> >> I'm
>> >> an extremist on this point. I don't allow for any kind of thinking
that
>> in
>> >> any way resembles vitalism.
>
>Vitalism, to my way of thinking, is just another way of saying we don't
>know what life is or how it got started. We do this with a lot of
>things that seem too big to grasp. It may be that it causes too much
>stress for most people to keep working on a big problem like this.
Vitalism is more than you intimate. It implies the existence of laws (not
just properties) that suddenly appear on the scene. There is a big
difference between laws and properties. Most vitalists--including many of
those that use couch their vitalism in the terminology of the science of
complexity--do not have a clear understanding of this distinction.
>
>So we often point to some notion that has no meaning and try to fool
>ourselves into believing that we have it all figured out. The big
>problem with quick fix notions like vitalism is that we give up trying
>to understand what things like life are. And so long as we give up
>trying to understand something like life, there is a 100 percent chance
>that we won't figure it out.
Yes. This is why scientist tend to get kind of irritated with vitalistic
thinking.
>
>> >>I don't even allow for the existence of
>> >> stochastic processes (ie. genetic drift) as a causal factor.
>> >
>> >How do you stand on the idea of sexual selection?...
>>
>> I see sexual selection as being sub-operative to natural selection.
>>
>> >and fitness selection?
>>
>> When fitness is properly defined I have no trouble with it. But I have
yet
>> to see fitness properly defined. Invariably the definitions I have seen
>> contain some greater or lesser absolutistic assumption(s). I have
redefined
>> fitness but I first had to redefine a lot of the underying terminology.
In
>> other words, if I was to state it to you right now you wouldn't have a
clue
>> what I was talking about. So I won't open that can of worms.
>
>I'm going to guess that your notion of fitness may not be too different
>from mine.
You're probably right about this. Believe it or not, once fitness is
properly defined (And believe me it is not easily achieved--you wouldn't
believe all the philosophical wrangling one has to go through to achieve the
reductive ideal in evolutionary theory) it becomes apparent how a species
(ourselves) could have evolved the kind of morality and altruism that we
have evolved.
So please spell it out and lets see how far apart we are.
I wish it was that simple.
>
>> >Do you think there is room for selection that is related to things other
>> >than pure deterministic fitness?
>>
>> No. (Again, assuming fitness is defined properly.)
>
>> >>
>> >> I breezed through your website. It has nice pictures but it isn't
>> >> scientific.
>> >
>> >I agree, it's not scientific in the narrow sense I assume you use and
>> >define the term. In fact, I go to lengths to say where I think what we
>> >normally call science is useful and where I think it causes a lot of
>> >grief.
>>
>> I agree science does cause a lot of grief. And more than any other
science
>> evolutionary theory, especially when it involves human origins, is the
>> source of grief. I am a strong proponent of selective censorship of
human
>> evolutionary theory. No kidding. In fact when the cause of human
evolution
>> is finally revealed. (And theis will happen very soon, take my word on
it.)
>> It will be made clear why it is that evolutionary theory (especially as
it
>> applies to implications on traditional beliefs of human origins--both
>> secular and religious) is such a source of grief.
>>
>
>
>What follows is why I think it's important to reconcile evolutionary
>theory with our secular and religious values:
In contrast I do not agree that we should reconcile evolutionary theory with
our secular and religious values. Human evolutionary theory is a Pandora's
box with a bottomless pit. This will become plainly evident when the cause
of human evolution is discovered. Our secular and religious beliefs are
multiplicitously more valuable to our continued survival than is human
evolutionary theory.
<snip>
>In biology, some have tried to reduce the way life forms evolve to a
>single phrase. Thus, many think that the "survival of the fit" is how
>life got to be the way it is. This meme, like many others we think came
>from science, has crept into our culture and value systems.
I agree.
The problem is that when fitness is properly defined it has no utiliterian
value at all because it involves what will happen in the future.
Unfortunately many people think that fitness of a lifeform is derivable from
observing the nature or actions of the lifeform. Actually what one is doing
when they do such is submitting a subjective judgement of the fitness of the
lifeform which, by definition, have no scientific validity.
>Most of us now grasp the fact that we humans have bent some of the laws
>of nature.
No way.
>Natural selection does not work the way it used to.
I disagree.
I don't know if you are referring to the notion, which seems to be gaining
popularity of late, that human advances have somehow stopped the progress of
evolution. I consider this notion to be ridiculous.
<snip>
>Science has shown us how to protect and extend our lives.
I define science as applied knowledge. According to this definition science
has been around a lot longer than has humans.
<snip>
>Then the Nazis took this meme to a new level. They said the unfit
>polluted the gene pool. And they killed millions whom they thus judged
>as not fit to live.
Those who practice eugenics can expect it to be reflected back upon them, as
was the case in WWII.
>Yet we've seen that even though our forebears were adaptable, they were
>not what we might call fit.
If they were'nt fit we wouldn't be here.
>But recall that it was this lack of fitness
>that helped them change their problems.
wrong.
>They changed their gene
>changing problems into thought problems. This led to a four fold
>increase in brain size and what we now call thought.
Your thinking here accurately reflects the current paradigm of evolutionary
theory. But it is wrong. Human intelligence did not evolve as a result of
the need to be intelligent in order that we could obtain sustenance. This
is putting the cart before the horse. If it was that simple we would expect
to see many other species that had also evolved in the same kind of
anamolous manner that humans have evolved. What actually happened can only
become evident if one is first able to get beyond the grasp of the
assumptions of the current paradigm. This is not easily achieved. People
tend to be seduced by their own ideas. The current attempts to explain
human evolution have evolved into self-pertetuating memes. Many is the
scientist that had scientifically superior theories but who did not achieve
success because they did not understanding the psychological barriers to the
acceptance of their theories. I figured out the cause of human evolution.
And it is, essentially ready to be released. But I am not going to release
it until I've had some experience wrestling with the paradigmatic
assumptions of the current paradigm.
>
>We saw that our forebears were good at living in the seams between
>habitats.
Yes. But it's important to understand that some theorists that submit
statements like this are implying that our "living in the seams between
habitats," was, somehow, the cause of human evolution. This supposition is,
at best, highly incomplete, at worst, it is ridiculous.
>There is now some evidence that they felt at home in places
>like a beach.
For the most part this is consistent with my understanding. We certainly
did not evolve in the savanna.
>Here they could go back and forth between the land and
>the sea.
Okay, but it did not involve any aquatic phase. This is unnecessary.
>They also liked to hang out in the trees that ran between the
>rain forest and the plains.
There's more to it than this.
>And they may have gone back and forth
>between many of these places including the mountains and the desert.
Not until long after the human species was firmly established.
>Yet in spite of all this, our forebears were not well suited to any one
>habitat. So they paid a big price for being adaptable. The price was
>that they did not fit well into any one habitat.
Again you're falling into the trap of trying to attribute the need to adapt
to the environmental factors of a habitat as being the cause of human
evolution. It didn't happen like this. Again, if it was this simple we
would have expected many other species to have done the same.
>
>We've seen that this is different from the way most species evolve.
>Most species evolve to fit into a tight niche in an ecosystem.
Yes. This is the proper way to frame the problem of human evolution. It's
kind of ironic, however, that those who are most educated in being able to
realize this are, by way of their education, least habituated to dealing
with a species that--somehow--broke out of being niche specific. (It is
interesting to note that the literal interpretation of what it means to be a
species is to be niche specific. So in that sense humans are not a species.
Within the community of naturalist at the time, it was for this reason that
Darwin's original supposition that humans were just another species was
considered so controversial. It literally goes against the grain of what
the term species was intended to indicate.)
<snip>
>And they also had to learn when, where and how to exploit a
>given habitat for food.
>
<snip>
>With all these choices, our forebears came to rely more and more on
>their brains. Still, they didn't physically fit any one of these
>habitats very well. In fact, it's no stretch at all to say that they
>were physically unfit.
No. This isn't how it happened. Trust me.
>So whether we like it or not, we use what we learn from science to help
>govern our selves. All this is why we need to be so careful with the
>theories and ideas that come from science. To me, this means that we
>need to pay close attention to the hypotheses that science comes up
>with.
>
I'll go you one step farther. We need to selectively censor many aspects of
human evolutionary theory.
>The point is that there are strong ties between our laws, our values and
>what we're learning. Once we recognize these ties, we can integrate
>what science teaches us with our value systems. Then, perhaps, we can
>do a better job setting up the rules we use to govern our selves.
I agree.
Jim McGinn
Marc Verhaegen
Dwight E. Howell heeft geschreven in bericht <3570C96A...@usit.net>...
>> snip
>> >The main changes were bipedalism, the acquisition of hands
>> >designed to grasp, and the loss of large canines. These fit far
>> >too well with club wielding for it not to be the main hypothesis.
>>
>> In an evolutionary perspective I think you have to explain all features
>> independently.
>> - striding bipedalism in primates is always wading (& gibbons walking
>> along branches perhaps)
>
>Please use more logic with what you say. If these organisms only walked
>as bipeds when in water they would have had to spend all their time in
>water or not become bipeds.
Okay, I meant that we when see regular bipedalism in nonhuman primates it is
in wading animals. Proboscis monkeys, eg, frequently wade bipedally in water
& occasionally run bipedally on land, they don't seem to leap on the ground
(in the trees they often do), but usu. run quadrupedally & occasionally
bipedally with striding gait (not leaping as in prosimians on the ground).
> It is reasonable to suspect that spending
>time in water (wadding) caused more bipedal locomotion but if it was
>completely restricted to such a location they would still be quadrupeds
>(most likely) as are modern apes when out of water. Please also read
>some modern research on chimp behavior and stop making blanket
>statements. Many sources report bipedal locomotion for a huge variety of
>reasons.
In chimps, yes, that's one of the reasons why I (& others) believe that
chimps had australopith-like ancestors (IMO the early australopiths were
wading/arboreal herbivores in shallow waters):
Australopithecine ancestors of African apes?
Palaeo-anthropological data do not exclude the possibility that chimpanzees
and gorillas could have had australopithecine-like ancestors. In fact, the
traditional hypothesis – that all australopithecines are closer relatives of
humans than of chimps or gorillas – has serious difficulties:
a. The apparent absence or extreme rarity of fossil ancestors or relatives
of any African ape is puzzling.
b. Various australopith-like features are present in premature but not in
adult African apes (e.g. relative orthognathy, less dorsal foramen magnum,
more orthogrady).
c. Australopiths lack the uniquely derived features that set Homo, at least
since erectus, apart from nonhuman primates (e.g. external nose, very large
brain, very long legs), and generally resemble the apes.
d. At the time of the robust australopiths there already lived more
humanlike creatures like KNM-ER 1470.
e. The Homo/Pan splitting time occurred at the time of the earliest
australopiths, so if humans descend from australopiths, there is no reason
to exclude chimpanzees.
The Laetoli footprints A and G suggest that australopithecines were partly
or fully bipedal. Bipedalism is generally considered to be the defining
feature of the hominids, which links australopiths with humans. But the
African apes’ locomotion is unique - plantigrady plus knuckle-walking - and
is easily derivable from the kind of “short”-legged plantigrade bipedalism
that is frequently seen in lowland gorillas wading in shallow waters and
occasionally in all African apes. If the African apes had more bipedal
ancestors, there is every reason to include them into the hominids – in
agreement with the comparative molecular evidence of DNA and proteins
("molecular clock").
Gerrit Hanenburg
Marc Verhaegen <Marc.Ve...@village.uunet.be> wrote:
>>Australopithecines were probably not fully bipedal and their
>>bipedalism was probably not as efficient as that of modern humans, but
>>the point is whether or not it was effective under given ecological
>>circumstances (and that may even include wading in swamp grassland,
>>but not necessarily or primarily. After all, wading is only one
>>"application" of bipedalism).
>Okay, but wading fits the microwear data of PF Puech.
Puech (1992) suggests that "the diet at Hadar might have contained a
large amount of very small abrasive particles that exerted an erasing
and a polishing action while at the same time coarser particles made
scratches" (p.1084). He also suggests that these very small particles
may have been opal phytoliths. These are present in many species of
Gramineae and Cyperaceae, not exclusively in those of swamp margins.
At best Puech's data suggests that the Hadar hominins MAY have fed on
swamp margin plants, but it's certainly no decisive evidence.
Puech, P-F. 1992. Microwear Studies of Early African Hominid Teeth.
Scanning Microscopy 6 (4): 1083-1088.
>>> - gorilla length in boisei ER-739, OH-36, L-40-19
>>Absolutely or relatively?
>Absolutely
There is no diagnostic craniodental material associated with these
specimens, so their assignation to Paranthropus boisei is uncertain.
For now they are best considered Hominidae gen. et sp. indet.
Long arms are most parsimoniously interpreted as a primitive retention
(symplesiomorphy).
>>Humerofemoral index in OH 62 is 95%, but as you know this specimen is
>>very fragmentary, so there may be a considerable error.
>>(Johanson et al. 1987 do not give confidence limits of their
>>estimate).
>"may be" - Why always choosing the less probable explanations?? why not just
>considering the logical conclusion - just considering, just try - that
>australopiths were evolving in the Afr.ape direction??
The alternative hypothesis (that Pan and Gorilla are not part of
Hominina (defined here as the clade that stems from the most recent
common ancestor of Ardipithecus ramidus and Homo)) is the more
parsimonious one.
>>A.afarensis DID have relatively long arms, mainly due to a relatively
>>long forearm (Kimbel et al. 1994. The First Skull and Other New
>>Discoveries of Australopithecus afarensis at Hadar, Ethopia. Nature
>>368: 450).
>Lucy did not belong to "afarensis" s.s. (Ferguson: "antiquus")
The majority of paleoanthropologists still consider AL 288-1 part of
the hypodigm of A.afarensis. There is enough craniodental and
postcranial similarity to consider A.afarensis as a single sexually
dimorphic species. We have no reason (yet) to accept the taxonomic
proposals of supersplitter Walter Ferguson.
>>>Why do you think this bearlike pinnipedimorph ancestor was "terrestrial"?
>>On the basis of anatomy and phylogenetic inference.
>>Pinniped anatomy is basically that of a quadrupedal mammal that, like
>>cetaceans, became secondarily aquatic.
>>Phylogeny: Ursidae is the sistertaxon of Pinnipedia. Procyonidae is
>>the sistertaxon of Ursida (= Ursidae + Pinnipedia).
>>Both Ursidae and Procyonidae are characterized by plantigrade
>>quadrupedal terrestrial locomotion. Therefore it is most likely that
>>this is the ancestral state.
>Polar & other bears & racoons are semi-aquatic (IMO the ancestral state of
>pinnipeds, bears & racoons)
Even the most aquatic of these animals, the polar bear, spends most of
its time out of the water, either on land or on the pack ice.
However, in the case of the polar bear I'm prepared to make an
exception, but to consider the others as semi-aquatic is your usual
overvaluation of occasional water contact (such as in the case of
Ursus arctos hunting salmon that move upstream to their spawning
grounds during a brief period).
Gerrit
Marc Verhaegen
>>Okay, but wading fits the microwear data of PF Puech.
>
>Puech (1992) suggests that "the diet at Hadar might have contained a
>large amount of very small abrasive particles that exerted an erasing
>and a polishing action while at the same time coarser particles made
>scratches" (p.1084). He also suggests that these very small particles
>may have been opal phytoliths. These are present in many species of
>Gramineae and Cyperaceae, not exclusively in those of swamp margins.
>At best Puech's data suggests that the Hadar hominins MAY have fed on
>swamp margin plants, but it's certainly no decisive evidence.
>
>Puech, P-F. 1992. Microwear Studies of Early African Hominid Teeth.
>Scanning Microscopy 6 (4): 1083-1088.
>
1998 Wetland apes: hominid palaeo-environment and diet
Marc Verhaegen & Pierre-François Puech
The combination of the available evidence from different anthropological
researches makes it clear that hominid evolution did not begin in warm and
dry but in warm and wet conditions.
a. No feature typical of savannah mammals is found in humans: low need of
drinking-water or succulent food; concentrated urine; tolerance of
dehydration and radiation heat; high diurnal body temperatures and daily
temperature fluctuations; high velocities; digiti/unguligrady; poorly
developed vocalisations and dexterity...
b. Comparative studies of cheekteeth microwear suggest that the australopith
diet included marshland plants (PF Puech). In afarensis, the enamel has a
polished surface (cf. mountain beaver, capybara: sappy aquatic herbs and
grasses, buds and bark of young trees). In boisei, it displays more pits,
wide parallel striations and deep recessed dentine (cf. beaver: aquatic
plants, bark, more woody parts). In habilis, the margins of the striae have
been polished and slightly etched (cf. coypu: reed, sedges, marsh plants,
fruits, molluscs).
c. Robust australopiths resemble reed/bamboo-eaters in front teeth reduction
and cheekteeth broadening (cf. gentle lemurs, giant panda, EL DuBrul), and
estimates of the robusts’ bite force also suggest “low-energy food… to be
processed in large quantities… hard and round in shape” (B Demes & N Creel).
d. The low Sr/Ca ratios in Swartkrans robusts have been explained by partial
carnivory (unlikely with their herbivorous dentition), eating leaves and
shoots of forbs and woody plants (cf. kudu) and eating food from wet,
well-drained streamside soils (A Sillen).
e. Palaeo-ecology indicates that early australopithecines lived in warm,
humid and often forested landscapes. Robust australopiths dwelt near more
open environments like grasslands, marshlands and lagoons. Homo species are
frequently found near ancient lakes, seas and rivers where molluscs were
abundant.
It seems that early australopiths were bipedal frugi/herbivores in forest
clearings (cf. western gorillas eat sedges, wading in shallow waters, D
Chadwik). The robusts later ate marshland plants like papyrus, reed, nuts
etc. Early Homo used stones to crack nuts and shellfish (cf. mangrove
capuchins, M Fernandes). This would explain stone tool use for other
purposes, the rapid spread to SE Asia, and the increase in brain size (SC
Cunnane).
>>>> - gorilla length in boisei ER-739, OH-36, L-40-19
>>>Absolutely or relatively?
>
>>Absolutely
>
>There is no diagnostic craniodental material associated with these
>specimens, so their assignation to Paranthropus boisei is uncertain.
>For now they are best considered Hominidae gen. et sp. indet.
>Long arms are most parsimoniously interpreted as a primitive retention
>(symplesiomorphy).
If it was not boisei, it must have been Gorilla (IMO both) - what else?
Dwight E. Howell
>
>
> The Laetoli footprints A and G suggest that australopithecines were
> partly
> or fully bipedal. Bipedalism is generally considered to be the
> defining
> feature of the hominids, which links australopiths with humans. But
> the
> African apes’ locomotion is unique - plantigrady plus knuckle-walking
> - and
> is easily derivable from the kind of “short”-legged plantigrade
> bipedalism
> that is frequently seen in lowland gorillas wading in shallow waters
> and
> occasionally in all African apes. If the African apes had more bipedal
>
> ancestors, there is every reason to include them into the hominids –
> in
> agreement with the comparative molecular evidence of DNA and proteins
> ("molecular clock").
Are there any fossils from the jungle regions of Africa that are apes
from this time frame? I have read enough to know that bodies don't
normally last long and the chance of becoming a fossil may be almost
zero. Still the info will be found given enough time. I agree that the
ancestors of African apes may have been more erect than they are but
don't care to claim that they were fully developed bipeds.
The problem to me is that the split seems to be to closely dated in
time to the known bipeds. I'm starting to wonder if more than one later
group may have become bipeds and maybe some of the earliest known are
cousins at best. It is strange that several lines of descent should
appear at about that time leading to apes and man from one rather
unknown animal while a host of other equally promising creatures went
poof.
The other question is which of these groups were species? They are
diverse enough to have been many especially when you look at how similar
modern African apes are and yet can't cross breed but if so why are all
the moderns derived from this single source?
I guess I saying that one or more of the African apes should logically
be a lot less closely related than they are. Or maybe the apes are just
loosing niches to the monkeys but even this doesn't seem to explain the
close relationship among all of them.
Dwight E. Howell
Marc Verhaegen wrote:
Several Savannah dwelling species of primates exist but none of them
have the features you call for so they must be able to get along without
them.
> b. Comparative studies of cheekteeth microwear suggest that the
> australopith
> diet included marshland plants (PF Puech). In afarensis, the enamel
> has a
> polished surface (cf. mountain beaver, capybara: sappy aquatic herbs
> and
> grasses, buds and bark of young trees). In boisei, it displays more
> pits,
> wide parallel striations and deep recessed dentine (cf. beaver:
> aquatic
> plants, bark, more woody parts). In habilis, the margins of the striae
> have
> been polished and slightly etched (cf. coypu: reed, sedges, marsh
> plants,
> fruits, molluscs).
But the wear patterns can be produced by eating other available foods so
they don't prove a limited diet.
> c. Robust australopiths resemble reed/bamboo-eaters in front teeth
> reduction
> and cheekteeth broadening (cf. gentle lemurs, giant panda, EL DuBrul),
> and
> estimates of the robusts’ bite force also suggest “low-energy food… to
> be
> processed in large quantities… hard and round in shape” (B Demes & N
> Creel).
> d. The low Sr/Ca ratios in Swartkrans robusts have been explained by
> partial
> carnivory (unlikely with their herbivorous dentition), eating leaves
> and
> shoots of forbs and woody plants (cf. kudu) and eating food from wet,
> well-drained streamside soils (A Sillen)
Chimps eat meat as do most other primates. Most are omnivores and tooth
shape doesn't change this.
> .
> e. Palaeo-ecology indicates that early australopithecines lived in
> warm,
> humid and often forested landscapes. Robust australopiths dwelt near
> more
> open environments like grasslands, marshlands and lagoons. Homo
> species are
> frequently found near ancient lakes, seas and rivers where molluscs
> were
> abundant.
>
The fact that something was there does not prove it was an important
part of the diet or even eaten at all by a given group. We need a
stronger connection.
> It seems that early australopiths were bipedal frugi/herbivores in
> forest
> clearings (cf. western gorillas eat sedges, wading in shallow waters,
> D
> Chadwik). The robusts later ate marshland plants like papyrus, reed,
> nuts
> etc. Early Homo used stones to crack nuts and shellfish (cf. mangrove
> capuchins, M Fernandes). This would explain stone tool use for other
> purposes, the rapid spread to SE Asia, and the increase in brain size
> (SC
> Cunnane).
>
It is not so much that I feel that what you say is untrue as that I feel
that it is only a part, possibly a very small part, of the truth.
> >>>> - gorilla length in boisei ER-739, OH-36, L-40-19
> >>>Absolutely or relatively?
> >
> >>Absolutely
> >
> >There is no diagnostic craniodental material associated with these
> >specimens, so their assignation to Paranthropus boisei is uncertain.
> >For now they are best considered Hominidae gen. et sp. indet.
> >Long arms are most parsimoniously interpreted as a primitive
> retention
> >(symplesiomorphy).
>
> If it was not boisei, it must have been Gorilla (IMO both) - what
> else?
Good question but currently unknown lines of apes may very well have
existed and I believe he sort of said that any of the above was possible
but unproved?
Marc Verhaegen
Dwight E. Howell heeft geschreven in bericht <357215D6...@usit.net>...
>>
>>
>> The Laetoli footprints A and G suggest that australopithecines were
>> partly
>> or fully bipedal. Bipedalism is generally considered to be the
>> defining
>> feature of the hominids, which links australopiths with humans. But
>> the
>> African apes’ locomotion is unique - plantigrady plus knuckle-walking
>> - and
>> is easily derivable from the kind of “short”-legged plantigrade
>> bipedalism
>> that is frequently seen in lowland gorillas wading in shallow waters
>> and
>> occasionally in all African apes. If the African apes had more bipedal
>>
>> ancestors, there is every reason to include them into the hominids –
>> in
>> agreement with the comparative molecular evidence of DNA and proteins
>> ("molecular clock").
>
> Are there any fossils from the jungle regions of Africa that are apes
>from this time frame? I have read enough to know that bodies don't
>normally last long and the chance of becoming a fossil may be almost
>zero.
Orangs do have fossilised probable relatives: Sivapithecus &
Gigantopithecus.
>Still the info will be found given enough time. I agree that the
>ancestors of African apes may have been more erect than they are but
>don't care to claim that they were fully developed bipeds.
IMO the australopiths were no "full" bipeds. They waded a lot to get their
food (sedges, reed...), walked bipedally on dry land, climbed in trees
(where the graciles must have been very agile), & possible swam a lot
(probably lumbar lordosis, full plantigrady...), but they were no
long-legged exclusive bipeds like we.
>
>The problem to me is that the split seems to be to closely dated in
>time to the known bipeds. I'm starting to wonder if more than one later
>group may have become bipeds and maybe some of the earliest known are
>cousins at best. It is strange that several lines of descent should
>appear at about that time leading to apes and man from one rather
>unknown animal while a host of other equally promising creatures went
>poof.
(what promising creatures do you mean? fossils? "went poof"=disappeared?)
Molec.data suggest the LCA of Homo/Pan/Gorilla lived ca.6 mya.
Fossils from Europe/Turkey (Ourano-Graeco-Ankarapith.) suggest close
relatives of hominids+ponigds might have lived in the Middle East ca.10 mya
(eg, Algaput etc.1996 "A new species of Ankarapith.meteai from... central
Anatolia" Nat.382:349).
>
>The other question is which of these groups were species? They are
>diverse enough to have been many especially when you look at how similar
>modern African apes are and yet can't cross breed but if so why are all
>the moderns derived from this single source?
We have the molecular data of splitting times:
- hominids=Pan+Homo+Gorilla / pongids=orang between 13-8 mya
- Gorilla /Homo+Pan between 5-8 mya
- Homo / Pan between 4-6 mya
- bonobo / common chimp ca.2 mya?
- western / eastern gorilla ca.2 mya?
- Pan troglodytes / verus ca.1.4 mya??
- Homo Africa / rest (or KhoiSan / rest?) 200-100,000 ya?
All australopiths no doubt belonged to the hominids (living members: Pan,
Homo, Gorilla). CE.Oxnard believes they did not belong Pan or Homo or
Gorilla, but to an other extinct hominid clade. Most anthropologists believe
australopiths were closer relatives of Homo than of Pan or Gorilla. IMO
africanus & robustus belonged to Pan, aethiopicus & boisei belonged to
Gorilla, see my papers:
1990. African ape ancestry. Hum.Evol.5, 295-297.
1994. Australopithecines: ancestors of the African apes? Hum.Evol.9,
121-139.
1996. Morphological distance between australopithecine, human and ape
skulls. Hum.Evol.11, 35-41.
1997. In den Beginne was het Water. Nieuwste Inzichten in de Evolutie van de
Mens. Hadewijch, Antwerpen.
Marc
Marc Verhaegen
The so-called savanna primates (eg, some baboons) stay in the shade during
midday. They need less water, are much faster than we, run on their toes.
They lack the typical human features sometimes attributed to savanna life
(nakedness, bipedality).
>> b. Comparative studies of cheekteeth microwear suggest that the
australopith
>> diet included marshland plants (PF Puech). In afarensis, the enamel has a
>> polished surface (cf. mountain beaver, capybara: sappy aquatic herbs and
>> grasses, buds and bark of young trees). In boisei, it displays more pits,
>> wide parallel striations and deep recessed dentine (cf. beaver: aquatic
>> plants, bark, more woody parts). In habilis, the margins of the striae
have
>> been polished and slightly etched (cf. coypu: reed, sedges, marsh plants,
>> fruits, molluscs).
>
>But the wear patterns can be produced by eating other available foods so
>they don't prove a limited diet.
True, but Dr Puech has studied hundreds of teeth electronmicroscopically
(all sorts of mammals & all sorts of fossil hominid teeth) & he sees most
resemblances with the semiaquatic herbivores mentioned above. He is
confident that afarensis, boisei & habilis did eat a lot of
aquatic/swamp/riverine plants (+ woody plants in boisei, and + acidic fruits
in habilis OH-16), but he admits that diets are always complicated & that
other food items might have been eaten too.
(Puech is also the man who cofirmed, through comparisons with old paintings,
that the skull unearthed a few years ago in a cimetary in Vienna was indeed
Mozart's.)
>> c. Robust australopiths resemble reed/bamboo-eaters in front teeth
reduction
>> and cheekteeth broadening (cf. gentle lemurs, giant panda, EL DuBrul),
and
>> estimates of the robusts’ bite force also suggest “low-energy food… to be
>> processed in large quantities… hard and round in shape” (B Demes & N
Creel).
At first I believed that A.boisei ate a lot of bamboo (my 1992 paper "Did
robust australopithecines partly feed on hard parts of Gramineae?"
Hum.Evol.7:63), but Puech doubts that, though he does not exclude it. Maybe
parts of reeds, he says.
>> d. The low Sr/Ca ratios in Swartkrans robusts have been explained by
partial
>> carnivory (unlikely with their herbivorous dentition), eating leaves and
>> shoots of forbs and woody plants (cf. kudu) and eating food from wet,
>> well-drained streamside soils (A Sillen)
>
>Chimps eat meat as do most other primates. Most are omnivores and tooth
>shape doesn't change this.
The canine reduction & the expansion of the cheekteeth in the robust
australopiths strongly suggest an almost purely herbivorous diet. The
parallelism in front teeth reduction & backteeth broadening of
africanus>robusts with bears>pandas and with lemurs>Hapalemur suggested IMO
bamboo or at least reed or cane eating.
(Chimps & gorillas love cane, gorillas eat different parts of bamboo
species.)
>
>> e. Palaeo-ecology indicates that early australopithecines lived in warm,
>> humid and often forested landscapes. Robust australopiths dwelt near more
>> open environments like grasslands, marshlands and lagoons. Homo species
are
>> frequently found near ancient lakes, seas and rivers where molluscs were
>> abundant.
>>
>The fact that something was there does not prove it was an important
>part of the diet or even eaten at all by a given group. We need a
>stronger connection.
Okay, but it's the coincience of all those indications (wooded & swampy
milieu, well-drained soil, small canines, large backteeth, glossy appearance
of the enamel...) that IMO provides a clear picture (comparative data, eg,
films of wading gorillas eating sedges & aquatic herbs).
>
>> It seems that early australopiths were bipedal frugi/herbivores in forest
>> clearings (cf. western gorillas eat sedges, wading in shallow waters, D
>> Chadwik). The robusts later ate marshland plants like papyrus, reed, nuts
>> etc. Early Homo used stones to crack nuts and shellfish (cf. mangrove
>> capuchins, M Fernandes). This would explain stone tool use for other
>> purposes, the rapid spread to SE Asia, and the increase in brain size (SC
>> Cunnane).
>>
>It is not so much that I feel that what you say is untrue as that I feel
>that it is only a part, possibly a very small part, of the truth.
(IMO a big part)
>> >>>> - gorilla length in boisei ER-739, OH-36, L-40-19
>> >>>Absolutely or relatively?
>> >
>> >>Absolutely
>> >
>> >There is no diagnostic craniodental material associated with these
>> >specimens, so their assignation to Paranthropus boisei is uncertain.
>> >For now they are best considered Hominidae gen. et sp. indet.
>> >Long arms are most parsimoniously interpreted as a primitive
>> retention (symplesiomorphy).
>>
>> If it was not boisei, it must have been Gorilla (IMO both) - what else?
>
> Good question but currently unknown lines of apes may very well have
>existed and I believe he sort of said that any of the above was possible
>but unproved?
The current thinking is that all hominid fossils in Africa between 4-1 mya
(thousands of fossils!) are closer relatives of humans than of chimps or
gorillas. Were then are the relatives of gorillas or chimps?? They say
chimps & gorillas had lifestyles not suited for fossilisation. But in Asia
we do find relatives of the orang (Siva & Gigantopith.).
Why not accept the obvious? That most or all australopiths are apes, not
apemen.
(Of course, if you were a fossil hunter, you would unconsciously prefer to
see a human ancestor lying in your hands than an ape ancestor, & it's
natural that you stress the humanlike features of "your" fossil. Later
investigators often obtain more detached views & often stress the apelike
features, but these studies come a few years after the discovery & don't
have the reputation of those who found the fossils.)
And of course, there are "problems" with australopiths being apes: evolution
has taken place & australopiths did not (yet) have the African ape
lifestyle: they had short canines, low ilia, more bipedalism & other
humanlike traits. IMO these australopith humanlike traits were the ancestral
condition of the LCA of Homo/Pan/Gorilla: a wading & arboreal (& IMO
swimming) creature in gallery/mangrove/swamp forests somewhere in the Middle
East or in Africa ca.6 mya.
(Molecular data ("clock") suggest that Gorilla & Homo-Pan split ca.6 mya and
Homo & Pan somewhat later.)
IMO, from a LCA somewhere along the Red Sea or Indian Ocean, first the
gorilla clade went inland upstream & became gradually less aquatic & more
terrestrial & herbivorous, and after 4 or 3 mya, some (=boisei) were almost
completely herbivorous.
Later the chimp clade, smaller-sized & more omnivorous, went inland in
Africa, & included africanus & robustus. (Parallel evolution in the gorilla
& (later?) the chimp clade?)
The human clade stayed longest at the coasts, developed shellfish-collecting
adaptations (stone use & diving), colonised S.Asia (H.erectus Java 2 mya),
and gave inland upstream offshoots into Africa, Asia & Europe, that - with
their tool use developed from stone use - gradually became less diving &
more fully terrestrial again.
Marc
Dan Barnes
In article <356d7a7a...@news.indigo.ie>,
crow...@hotmail.com.nospammers says...
>
>On Wed, 27 May 1998 03:29:46 +0200, "Marc Verhaegen"
><Marc.Ve...@village.uunet.be> wrote:
>
>>Paul Crowley heeft geschreven in bericht
<356ac93...@news.indigo.ie>...
>>> Hominids (normal definition)
>>>could walk and their fossils may be found a long way from their
>>>habitat, especially if their normal habitat was not suitable for
>>>fossilization.
>>
>>Why do you think the australopith habitat was not suitable for
>>fossilisation?
>
>I maintain that the hominid (normal definition) habitat for the
>last 5 Myr has been the littoral. It's where, broadly speaking,
>they concentrate today. Littorals are poor places for
>fossilization. There absorb enormous amounts of energy and sea
>levels are constantly rising and falling, destroying the
>evidence. The obvious way for a littoral population to expand
>is to go inland. And almost every generation would export its
>surplus young in that direction. Generally they would finish up
>beside some lake or water hole, possibly buried in a shallow
>grave by their companions, sometimes suffering from the effects
>of vitamin-A poisoning after eating their dogs. This is the only
>reasonable account for the condition of my favorite fossil KNM-ER
>1808. Another vitamin-A-poisoned fossil was found at Venosa in
>Italy dated to about 0.5 mya.
>
fossil but I don't recall mention of vitamin A poisoning (which of course doesn't
mean its not mentioned). If you could tell me which of these papers it is
mentioned in it'll help narrow down the search:
Belli, G., Belluomini, G., Cassoli, P.F., Cecchi, S., Cucarzi, M., Delitala, L.,
Fornaciari, G., Mallegni, F., Piperno, M., Segre, A.G. & Segre-Naldini, E.
(1991) Découverte d’un fémur humain acheuléen à Notarchirico (Venosa,
Basilicata). L’Anthropologie. 95 (1). 47 - 88.
Cassoli, P.F., Lefèvre, D., Piperno, M., Raynal, J.-P. & Tagliacozzo, A. (1993)
Una paleosuperficie can resti di Elephas (Palaeoloxodon antiquus) e industria
acheuleana nel sito di Notarchirico (Venosa, Basilicata). Atti della XXIV
Riunione Scientifica dell’Istutuo Italiano di Preistoria e Protostoria (Firenze,
1991). 101 - 16.
Lefèvre, D., Raynal, J.-P., Pilleyre, T. & Vernet, G. (1993) Contribution à la
chronostratigraphie de la serie de Venosa-Notarchirico (Basilicata). Atti della
XXIV Riunione Scientifica dell’Istutuo Italiano di Preistoria e Protostoria
(Firenze, 1991). 117 - 28.
Lefèvre, D., Raynal, J.-P., Vernet, G., Pilleyre, T., Piperno, M., Sanzelle, S., Fain
J., Maillier, D., Montret, M. (1994) Sédimentation, volcanisme et présence
humaine dans le bassin de Venosa (Basilicata, Italie) au Pléistocène moyen:
Exemple du site de Notarchirico. Bulletin de la Société Préhistorique
Française. 91 (2). 103 - 12.
Piperno, M. (1996) Notarchirico (Venosa, Potenza). In Gambassini, P., Martini,
F., Palma di Cesnola, A., Peretto, C., Piperno, M., Ronchitelli, A. & Sarti, L.
(eds) Guide Archeologiche. Preistoria e Protohistoria in Italia. Volume 1. Il
Paleolitico dell’Italia Centro-Merdionale. XIII International Congress of
Prehistoric and Protohistoric Sciences. Forlì, Italia - 8/14 September 1996.
A.B.A.C.O., Forlì. 91 - 7.
Piperno, M., Mallegni, F. & Yokoyama, Y. (1990) Découverte d’un fémur humain
dans les niveaux acheuléens de Notarchirico (Venosa, Basilicate, Italie).
Comptes Rendus de l’Académie des Sciences (Paris). Série II. 131 (9). 1097 -
1102.
Also Paul I'm never sure how serious you are but the evidence at Notarchirico
(Venosa) shows that the hominids were entering the area around Mount Vulture
immediately after a volcanic eruption and exploiting the dead animals there. I
can't think of any archaeological evidence in the Palaeolithic for dog eating - but
you could set me right on this. Also the Venosa 1 femur probably dates to c. 300
ka - the 500 ka being from AAR which is affected by numerous environmental
factors 500 ka is around its upper limit (although all the dates for this site are
problematic).
Dan
Gerrit Hanenburg
Marc Verhaegen <Marc.Ve...@village.uunet.be> wrote:
>(Molecular data ("clock") suggest that Gorilla & Homo-Pan split ca.6 mya and
>Homo & Pan somewhat later.)
Which poses more problems for your scenario.
The oldest fossil that can be assigned to Paranthropus (L55-s-33, a
mandibular fragment from Submember C-6 of the Shungura Formation) is
dated at ca. 2.7 Mya, postdating the split between Gorilla and
Pan+Homo by ca 3.3 Myr.
Gerrit
Gerrit Hanenburg
Marc Verhaegen <Marc.Ve...@village.uunet.be> wrote:
>>- gorilla length in boisei ER-739, OH-36, L-40-19
>>There is no diagnostic craniodental material associated with these
>>specimens, so their assignation to Paranthropus boisei is uncertain.
>>For now they are best considered Hominidae gen. et sp. indet.
>>Long arms are most parsimoniously interpreted as a primitive retention
>>(symplesiomorphy).
>If it was not boisei, it must have been Gorilla (IMO both) - what else?
They're unlikely to be Gorilla (they lack the deep olecranon fossa
with steep and sharp lateral margin and the proximoanterior
orientation of the trochlear notch and heavily buttressed coronoid
process characteristic of the knucklewalking apes).
They are probably P.boisei, but their taxonomic status is uncertain
without associated diagnosable craniodental material, since isolated
early hominin postcranial elements are difficult to diagnose (as
McHenry (1994: 258) suggests, these large forelimbs may also belong to
the species with the largest hindlimbs (e.g. KNM-ER 1481, possibly
Homo rudolfensis).
McHenry, H.M. 1992. Early Hominid Postcrania: Phylogeny and Function.
In Corruccini, R.S. & Ciochon, R.L. 1992. Integrative Paths to the
Past. Prentice Hall. pp.251-268.
Gerrit
Norman K. McPhail
> >Jim McGinn wrote:
> >>
> >> Boy have you gotten the wrong impression from my previous post. I am the
> >> most deterministic, reductionistic, and mechanistic (in addition to being
> >> relativistic as opposed to being absolutistic) scientist that I know.
> >
Then Norm McPhail wrote:
> >This is the second time this year I've been wrong. And boy was I wrong.
> >How did I get such a wrong impression? Perhaps because as you say, you
> >are relativistic? Regardless, I still found a lot that rang true in the
> >post you refer to.
> >
And Jim responded:
> It is insightful on your part that you keyed in on my relativistic aspects
> to my approach. This is the one area where I differentiate my thinking from
> that of traditional evolutionary biologists, ie. Dawkins. Dawkins work,
> which pretty much reflects the current paradigm, is chock-full of
> absolutistic assumptions. It is these absolutistic assumptions that--when
> combined with reductionism, mechanism, and determinism--are the source of
> the anti-human aspects of evolutionary theory. The problem is not
> reductionism, mechanism, and determinism in themselves. (I can prove this.)
In the context of the topics discussed in this news group, is there any
consensus about what the terms relativist and absolutist mean?
What does it mean to be an absolutist with respect to the various
alternative sequences for the evolution of apes and homo in Africa?
Does an absolutist demand some special form of physical evidence? Or do
they just disagree as to what constitutes physical evidence?
Since this evidence can sometimes be reasonably interpreted in several
ways, don't even the absolutists try to relate all aspects of the
evidence we can gather into a plausable scenario? Isn't this of
necessity relational? And, at least for now, aren't all the ideas they
put forth speculative to some degree?
So can't both relativists and absoltutists speculate and guess what all
the data we have means? If this is the case, what then is the
difference between those who call themselves relativists like Jim McGinn
and those who think of themselves as absolutists?
Marc Verhaegen
Gerrit Hanenburg heeft geschreven in bericht
<3572bcfa...@news.kijfhoek.nl.net>...
>Marc Verhaegen <Marc.Ve...@village.uunet.be> wrote:
>
>>(Molecular data ("clock") suggest that Gorilla & Homo-Pan split ca.6 mya
and
>>Homo & Pan somewhat later.)
>
>Which poses more problems for your scenario.
>The oldest fossil that can be assigned to Paranthropus (L55-s-33, a
>mandibular fragment from Submember C-6 of the Shungura Formation) is
>dated at ca. 2.7 Mya, postdating the split between Gorilla and
>Pan+Homo by ca 3.3 Myr.
IMO, boisei is in the gorilla clade. I don't see your problem?
1990. African ape ancestry. Hum.Evol.5:295-297
1991. Aquatic features in fossil hominids? M. Roede. The Aquatic Ape: Fact
or Fiction? Souvenir
1994. Australopithecines: ancestors of the African apes? Human Evolution 9,
121-139.
1996. Morphological distance between australopithecine, human and ape
skulls. Hum.Evol.11:35
1997. In den Beginne was het Water. Hadewijch Antwerp
See esp. the 1994 paper. Please read it first.
As Schultz already noted ("Taung ape"), there is nothing typically human in
the australopiths. They have no big brains (<600cc), no external nose, no
very long legs...
Bipedality is seen in all Afr.apes, esp. in young individuals & in western
lowland gorillas & bonobos.
Rel.anterior foramen magnum is seen in all premature apes & in bonobos.
Some australopiths had larger canines than bonobos.
Molar enamel thickness has changed several times in evolution (hard vs tough
diet?).
Orthognathy is seen in young apes & +- in bonobos.
Laetoli G footprints fit at least female mountain gorilla feet (see figs
Schultz) as human feet.
Moreover, later australopiths developed apelike features: longer arms in
OH-62 than in Lucy, very long arms in ER-739 (gorilla length), ectocranial
crests. This means: early australopiths were often more humanlike (cf. last
common ancestor), later ones more apelike.
My opinion at this moment:
-Very large E.African australopiths (aethiop., boisei, perhaps large
"afarensis"?): most related to gorillas?
-Very small ones (Lucy, Taung, ER-1813...?): most related to chimps/bonobos?
but, of course, more related to humans than to gorillas (cf. molec.tree).
-ER-1470 "habilis/rudolfensis": most related to humans?
For instance, some "gorilla" features in large E.Afr. skulls (apart from
their "apelike" features):
-size & general shape of skull & dentition
-"Incisal dent.microwear in A.afar. is most similar to... Gorilla" (Ryan &
Johanson 1989)
-Composite skull (AL-333) "looked very much like that of a female gorilla"
(Johanson & Edey 1981)
-"Other primitive (MV: read: "advanced gorilla-like") features found in
WT-17000 but not known or much discussed for A.afar. are: very small
cran.capacity, low post.profile of cavaria, nasals extended far above the
frontomax.suture & well onto an uninflated glabelle, and extremely convex
inferolat. margins of the orbits such as found in some gorillas" (Walker
etc.1986)
-Max.parietal breath & biauriculare in OH-5 & ER-406: "the robust austr.
have values near the Gorilla mean: both the pongids (MV: read: "gorillas") &
the robust austr. have highly pneumatized bases" (Kennedy 1991)
-OH-5: "the curious & characteristic features of the Paranthr.skull...
parallel some of those of the gorilla" (Robinson 1960)
-The A.boisei "lineage has been characterized by sexual dimorphism of the
degree seen in modern Gorilla for the length of it known history" (Leakey &
Walker 1988)
-A.boisei teeth "rel. absence of prism decussation"; among living hominoids
"Gorilla enamel showed rel? little decussation" (Beynon & Wood 1986)
A.robustus (you seem to like the term Paranthr. which is paraphyletic:
parallelisms) IMO belonged to the chimp clade, eg, intrapalatal extension of
the maxillary sinus has only been reported in the Taung child, chimps &
robustus among higher primates
(Bromage & Dean 1985 Nat.317:525)
The problem of all reconstructions is, of course, parallel evolution (eg,
the so-called "robust polyphyly" robustus//boisei). Animals that adapt to
comparable milieus & diets become more alike phenotypically. See some
extreme parallelism between marsupials & placentals. Between close
relatives, only detailed analysis can reveal the differences(eg, the large
size & large sexual dimorphism, & the extremely convex inferolateral margins
of the orbits & low prism decussation suggest boisei~gorilla, and
intrapalatal maxillary sinus suggests robustus~chimp).
Philip Deitiker
On Mon, 01 Jun 1998 11:27:52 -0700, "Norman K. McPhail"
<no...@socal.wanet.com> wrote:
>
>In the context of the topics discussed in this news group, is there any
>consensus about what the terms relativist and absolutist mean?
I have no idea what the aforementioned personal debate is about;
however relative vs. absolute are easily defined. An absolute
perspective is based upon a firm boundary, for example kelvin is based
on temperature above the lowest possible temperature (O'k) at which
temperature molecules lack vibrational motion. Celcius and Farenhiet
are basen on the temperatuer relative to frozen water and saline
respectively. The scale in all three systems is relative, in K and C
its relative * 100 to the freezing/boiling temps of water (and again
boiling point is relative to atmospheric pressure). There are few
things that are absolute. For example there are no absolute centers of
reference for either position, speed, or acceleration. This was
brought up by einstein. One could argue the universe is centered
around the unit of expansion, but roughly speaking in the space time
continuoum its very difficult to say where that position is in useful
units (which right now is about 10E-10M). Even if one could do this,
it would only be good for that moment.
>What does it mean to be an absolutist with respect to the various
>alternative sequences for the evolution of apes and homo in Africa?
Defining that the 7 million years of seqeunce would be restricted to
africa would be an unjustifyably absolutist perspective.
>Does an absolutist demand some special form of physical evidence? Or do
>they just disagree as to what constitutes physical evidence?
Like a reasonably complete skeleton, or a skeleton at varying sizes
druing development and of both sexes, and associated with cultural
artifacts which give insight into intelligence.
>Since this evidence can sometimes be reasonably interpreted in several
>ways, don't even the absolutists try to relate all aspects of the
>evidence we can gather into a plausable scenario? Isn't this of
>necessity relational? And, at least for now, aren't all the ideas they
>put forth speculative to some degree?
>So can't both relativists and absoltutists speculate and guess what all
>the data we have means? If this is the case, what then is the
>difference between those who call themselves relativists like Jim McGinn
>and those who think of themselves as absolutists?
Sticks and stones.
I might point out that there is no absolute way of knowing which
artifacts represents those specimens which were part of our anscestral
lineages and which were not, as one goes back in time the problem gets
even worse, and most probably the best guesses of today are wrong.
What one could argue is that within certain bounds of uncovered
morphology that a reasonable estimate of (range of morphologies that
might explain proto-humans at a given time) morphology can be made. An
absolute perspective, I guess, would argue that one cannot estimate a
morphology without having a unique skeletal model (an artifact to base
it on) this is as a matter of point always incorrect because there is
variation in every population and one has to make the assumption that
the morphology represents an average morphology in every regard. IOW a
sampling of one is not a representative sample unless one is sampling
clones. In any case, because of the rather obvious gaping holes in
human evolution (10 my to 100 ky) I would expect that the range would
widen to include many possibilities as one goes back into time.
Don't get me wrong though, I do think that proto-humans are not being
one thing on one day and another thing the next, we currently exhibit
many traits of all our ancestral intermediates, some new traits and
the lack or modification of old traits, roughly speaking one has to
accept bounds on variation that occured in the development, Thus
humans did not grow gills (or blow up malicious overlords in
supertankers) and we did not sprout fins.
Just for the intellectual excerise. a hydrogen atom consisting of one
proton, no neutrons and a single electron at 0'K has a given mass.
As with other matter defined by their mass. electric and magnetic
felids can be defined at the atomic level also. Thus there are
absolute points of reference for which to compare things in the
physical sense. Thus very simple things can have properties defined in
absoloute terms. A population is not a simple thing, it is complex.
Humans, in particular, defy defintion in absolute terms (likewise
anything that has 10E10 nucleotide genome in a recombining sexually
reproducing population), by the time you define the population, it has
already changed. It is even difficult to define what selective
pressures operated on humans, and even more difficult to define how've
they changed. At some point one has to realize that heisenberg's
uncertainty principle applies to this type of phenomena, also, and
future only changes probability of a correct resolution (or more
correctly refines the range of highest probability) rather than gives
more absolute answer. The absolute answer is all the animals that
lived which via sexual reproduction gave rise to animals which
eventually gave rise to members of the extant population. One can
define all such populations over time statistically and what science
seeks to know is what that statistical landscape of proto-humans
looked like. Thus I don't even think the long term desire is for an
abosoute answer, even if it could be achieved. One might able to
answer the question is this artifact a representative of that lineage,
but, without DNA, one can only tell whether it could or could not have
been, because bone morphology is not holo-morphology and it is
possible that two species with essentially overlaping range of bone
morpholgy differed with respect to cross fertility and other
morphological aspects, or geographic range and evolutionary destiny.
On the other hand one could take a pruely relative perspective, if for
a given period on finds a bone of a hominid, and there are no other
bones, then it is the most likely protohuman morphology, the next bone
found in the period either increases of decrease probability. Is one
to assume that the most human-like find is going to be the most
closely related species.
Lets take an example, there are two species of animals during three
periods. The first period is the common period, where the two animals
can but don't interbreed for whatever reason, the second period the
poulation of both grow and shrink independently of one another, in the
third period one displaces the other. If one looks soley at
morphology and relative bases one conclusion on discoverd fossiles one
can see a gradual transition from species AB to B then an ubrupt
change to A. What actually may have happened is that B is highly
represented in the record A is not in period 2 and in period 3 A
displaces B without genetic exchange. Even if one has 100 peices of
evidence for period 2 B and none for A it is not a foregone conclusion
that period 3 A evolved from period 2 B. Thus basing conclusions on
relative closenes to human or some established protohuman model is not
neccesarily going to give the best results. There is firm evidence for
population constrictions in humans in the past, how many times during
the past is unknown, but one foregone conclusion is that there will be
times when artifacts representing the human lineage are going to be
very scarce relative to other hominid competitiors. IOW one can go
out and buy 999,000 of a million lottery tickets you're still not
always garanteed a win, and evolution is full of extinct majority
populations.
Philip
<pdeitik at bcm.tmc.edu>
Norman K. McPhail
Jim McGinn wrote:
>
> Norman K. McPhail wrote in message <356F12...@socal.wanet.com>...
> >Jim McGinn wrote:
> >> Norman K. McPhail wrote in message <356DD0...@socal.wanet.com>...
> >> >Jim McGinn wrote:
> >> >> Norman K. McPhail wrote in message <356C9B...@socal.wanet.com>...
> >> >> >Paul Crowley wrote:
> >> >> >> On Tue, 26 May 1998 16:52:51 -0700, "Jim McGinn"
> >> >> >> <jimm...@msn.com> wrote:
> >> >> >> >>Paul Crowley heeft geschreven in bericht
> >> >Jim wrote:
[snip]
>
> I agree that we have the blind spot, but I don't agree that it's a problem.
> I see it as a survival mechanism.
I agree. I just say it is a set of two track data processing systems
that enabled our forebears to survive. They include: (1) the visual
spliting of objects and motions; (2) the linguistic system that splits
nouns and verbs and (3) the thought processing that splits problems from
solutions.
> Although it seems almost too ironic, once you understand what caused human
> evolution you come to realize why it is that our species has evolved a
> natural resistance to scientific based explanations of human origin--you
> come to realize what is meant by the biblical advice that we not eat the
> fruit from the tree of knowledge.
Interestingly, I think that in many ways, our two track data processing
systems force to see how we got to be the way we are in a dualistic way
that misses many of the links and loops thought fed on its own
benefits.
> Human evolutionary theory is the ultimate Pandora's Box.
Agree. I also think it takes special thought modes and assumptions to
fully understand. I wonder how far apart we are on the need for
multiple, linked and paradoxical thought modes to understand the whole
process. You might want to skim through part 5 SYNTHETIC BOOM TIMES,
and look at the FEEDBACK LOOP I suggest. It may be similar to what you
have in mind. http://204.94.86.93/5.html
> >Vitalism, to my way of thinking, is just another way of saying we don't
> >know what life is or how it got started. We do this with a lot of
> >things that seem too big to grasp. It may be that it causes too much
> >stress for most people to keep working on a big problem like this.
>
> Vitalism is more than you intimate. It implies the existence of laws (not
> just properties) that suddenly appear on the scene. There is a big
> difference between laws and properties. Most vitalists--including many of
> those that use couch their vitalism in the terminology of the science of
> complexity--do not have a clear understanding of this distinction.
Good point!
> >> >>I don't even allow for the existence of
> >> >> stochastic processes (ie. genetic drift) as a causal factor.
> >> >How do you stand on the idea of sexual selection?...
> >> I see sexual selection as being sub-operative to natural selection.
> >> >and fitness selection?
[snip]
> >I'm going to guess that your notion of fitness may not be too different
> >from mine.
> You're probably right about this. Believe it or not, once fitness is
> properly defined (And believe me it is not easily achieved--you wouldn't
> believe all the philosophical wrangling one has to go through to achieve the
> reductive ideal in evolutionary theory) it becomes apparent how a species
> (ourselves) could have evolved the kind of morality and altruism that we
> have evolved.
You seem to be suggesting a need to transcend the visual
objective/subjective perspective metaphor. If so, we may again agree on
one more aspect of the "problem."
> So please spell it out and lets see how far apart we are.
> I wish it was that simple.
I think I understand how difficult this is to express in a language
system that uses another form logic. You might want to see if we are
trying to get at the same thing by reviewing parts 17 through 25 of THE
DAWN OF HUMAN UNDERSTANDING (DOHU).
> >What follows is why I think it's important to reconcile evolutionary
> >theory with our secular and religious values:
> In contrast I do not agree that we should reconcile evolutionary theory with
> our secular and religious values. Human evolutionary theory is a Pandora's
> box with a bottomless pit. This will become plainly evident when the cause
> of human evolution is discovered. Our secular and religious beliefs are
> multiplicitously more valuable to our continued survival than is human
> evolutionary theory.
We agree on this point. I first try to cover these issues in DOHU parts
14 through 16. But we don't agree that wh ought to build a fire wall
between what science teaches us and our values, rules, culture and laws.
Once we learn how these realms differ and are alike, it will improve
both science and our beliefs and values. I try to lay all this out in
DOHU parts 26 through 33.
> >Most of us now grasp the fact that we humans have bent some of the laws
> >of nature.
> No way.
Would you agree that we use the way nature works for our own benefit?
Would you agree that the human definition of survival of the fit that
benefits us is different from the survival of the fit where our benefit
is not injected into the mix?
We might agree on these things. But I doubt that you would agree with
me when I claim that there are no laws of nature. Still, when I get
through explaining why I think what we call "the laws of nature" are
caused blind spot, we might agree to some extent.
> >Natural selection does not work the way it used to.
> I disagree.
I think we may just be quibbling about what is natural and what is
caused by the likes of us humans. We can argue forever about whether
humans are capable of unnatural acts. To me, this is one of those times
when two things are both the same and different at the same time. Is
there a good reason why they cannot differ and be alike at the same
time?
>
> I don't know if you are referring to the notion, which seems to be gaining
> popularity of late, that human advances have somehow stopped the progress of
> evolution.
No, I'm not. I don't think evolution "progresses." Things just keep
changing.
> I consider this notion to be ridiculous.
>
So do I.
>
> >Science has shown us how to protect and extend our lives.
>
> I define science as applied knowledge. According to this definition science
> has been around a lot longer than has humans.
You won't get any arguement form me on this point.
> >Then the Nazis took this meme to a new level. They said the unfit
> >polluted the gene pool. And they killed millions whom they thus judged
> >as not fit to live.
>
> Those who practice eugenics can expect it to be reflected back upon them, as
> was the case in WWII.
The rights and freedoms of individuals is the central issue behind most
if not all the wars of the last three centuries.
> >Yet we've seen that even though our forebears were adaptable, they were
> >not what we might call fit.
>
> If they were'nt fit we wouldn't be here.
Again, I'm making an arbitrary division between physical and mental
fitness. You seem to be saying they are the same thing. I just say
they are both the same and differ. Is there a good reason why they
can't be the same and different?
Isn't there something to be learned by understanding the interplay
between mental and physical fitness. Can't most people handle this
without going to the extreme of making them entirely seperate. On the
other hand, isn't making mental and physical fitness an indivisible
fitness just as extreme and misleading?
> >But recall that it was this lack of fitness
> >that helped them change their problems.
>
> wrong.
Would you buy it if I inserted the word "physical" before fitness?
> >They changed their gene
> >changing problems into thought problems. This led to a four fold
> >increase in brain size and what we now call thought.
>
> Your thinking here accurately reflects the current paradigm of evolutionary
> theory.
I have no idea what the current paradigm of evolutionary theory is. Yet
my guess is that there would not be many who would agree with my theory.
So it's hard for me to imagine that my notions reflect the current
paradigm.
For the record, I'll just state that one of the central ideas in my
theory is that as our forebears were forced to jump back and forth
between habitats for both food and safety. This meant that they had to
deal with an expanding number of choices. And these choices also were
getting more and more abstract and difficult to make.
The ones who made the best choices and applied their long list of
talents to novel solutions were the survivors. Thus those who developed
ways to deal with what we would now call problems were more often the
survivors. So I think it was the growing use of this problem and
solution frame of reference that helped them adapt and anticipate.
I think that Bill Calvin provides a good case in point with his throwing
hypothesis. Yet there are many other examples such as the use of sticks
and stones to extract marrow and break open shells. I think there were
literally thousands of these innovations. To me all the foresight and
development of multiple talents were born out of necesssity. And one of
these necessities was their lack of fitness for any one particular
niche. And the further they went down this path, the more they came to
depend on their wits.
But it is wrong. Human intelligence did not evolve as a result of
> the need to be intelligent in order that we could obtain sustenance.
Are you saying that safety and sustneance do not drive change? Are you
saying that changing food sources and threats don't select for
individuals who can find ways to meet these new tests? Or are you
saying that in the case of our forebears there was a set of conditions
and sequences that caused them to jump to a different mode of adapting
to these tests? One that is some ways was qualitatively different.
Does this have something to do with your earlier point on the
differences between properites and laws?
This
> is putting the cart before the horse. If it was that simple we would expect
> to see many other species that had also evolved in the same kind of
> anamolous manner that humans have evolved.
I couldn't agree more. I think it is confusing and even paradoxical in
many ways. There are things like r and K-shifts, migrations, feelings
of pain and well being along with a whole host of genetic, ecological
and environmental factors.
I don't claim to be a scientist as you know. But I have taken great
pains to blend an amazing array of factors into the process. I am
certain that I've made lots of mistakes, but in this case I think if you
read through DOHU you'll find that this was not one of them.
> What actually happened can only
> become evident if one is first able to get beyond the grasp of the
> assumptions of the current paradigm. This is not easily achieved.
On this we agree completely.
> Many is the
> scientist that had scientifically superior theories but who did not > achieve
> success because they did not understanding the psychological barriers > to the
> acceptance of their theories.
I think we've both experienced this. It is really hard to frame the
issue and know where we can build on common understandings of who and
what we are. It is equally hard to know exactly how and where to help
people discard their long held ideas and assumptions for a better model
of how we got to be the way we are.
> I figured out the cause of human
> evolution.
It's small joke, but I still there is a lot of truth in what I modestly
call my grand unified theory. It includes what I think is a good
understanding of who and what we are and how we got to be this way. I
might add that if our ideas are as similar as I suspect, we may be on to
something.
> And it is, essentially ready to be released. But I am not going to release
> it until I've had some experience wrestling with the paradigmatic
> assumptions of the current paradigm.
For what it's worth, I'd be happy to share my thoughts on this very real
and illusive problem. It might even be something a good media expert
might be able to help with.
> >
> >We saw that our forebears were good at living in the seams between
> >habitats.
>
> Yes. But it's important to understand that some theorists that submit
> statements like this are implying that our "living in the seams between
> habitats," was, somehow, the cause of human evolution. This supposition is,
> at best, highly incomplete, at worst, it is ridiculous.
We agree again!
>
>
> >And they may have gone back and forth
> >between many of these places including the mountains and the desert.
>
> Not until long after the human species was firmly established.
I wasn't certain of this. Can you provide any sources or individuals
who could say more specifically when these mountain and desert as well
as higher latitude excursions might have taken place? Most of what I
have used is taken from Calvin's speculations on ice age migrations.
> >Yet in spite of all this, our forebears were not well suited to any one
> >habitat.
>
> Again you're falling into the trap of trying to attribute the need to adapt
> to the environmental factors of a habitat as being the cause of human
> evolution. It didn't happen like this. Again, if it was this simple we
> would have expected many other species to have done the same.
This is a gross simplification and summary of earlier accounts in DOHU
which have a better and fuller list of the factors. You amy also be
interested to learn that I used a fuzzy cognitive map to build and
refine my mental model of this whole process. I don't think any who has
seen that model would say it was too simplistic. Still, I know that it
is a simplistic, redustionistic, deterministic mathematical model. It
is mainly useful as a feed back tool to help integrate a virtual mental
simulation.
>
> >
> >We've seen that this is different from the way most species evolve.
> >Most species evolve to fit into a tight niche in an ecosystem.
>
> Yes. This is the proper way to frame the problem of human evolution. It's
> kind of ironic, however, that those who are most educated in being able to
> realize this are, by way of their education, least habituated to dealing
> with a species that--somehow--broke out of being niche specific.
What a great way to phrase this phenomenon.
> (It is
> interesting to note that the literal interpretation of what it means to be a
> species is to be niche specific. So in that sense humans are not a species.
> Within the community of naturalist at the time, it was for this reason that
> Darwin's original supposition that humans were just another species was
> considered so controversial. It literally goes against the grain of what
> the term species was intended to indicate.)
>
> <snip>
>
> >And they also had to learn when, where and how to exploit a
> >given habitat for food.
> >
>
> <snip>
>
> >With all these choices, our forebears came to rely more and more on
> >their brains. Still, they didn't physically fit any one of these
> >habitats very well. In fact, it's no stretch at all to say that they
> >were physically unfit.
>
> No. This isn't how it happened. Trust me.
Can you elaborate? It would really help to see how you might rephrase
this paragraph. Besides, I always am a bit leary of anyone who says
"trust me."
> >So whether we like it or not, we use what we learn from science to help
> >govern our selves. All this is why we need to be so careful with the
> >theories and ideas that come from science. To me, this means that we
> >need to pay close attention to the hypotheses that science comes up
> >with.
> >
>
> I'll go you one step farther. We need to selectively censor many aspects of
> human evolutionary theory.
As I said above, I think there is a way to deal with the conflicts in a
constructive way that will work better over the long run than this
sweeping it under the rub suggestion.
> >The point is that there are strong ties between our laws, our values and
> >what we're learning. Once we recognize these ties, we can integrate
> >what science teaches us with our value systems. Then, perhaps, we can
> >do a better job setting up the rules we use to govern our selves.
>
> I agree.
>
So perhaps we can agree that there might be a way to tell the story of
human evolution the way it is and still integrate it into our social,
cultural, political and religious systems.
Paul Crowley
>Paul Crowley >Drox
>
>>>> Most primates have large canines. The australopiths lost theirs.
>>>> This *must* mean that they no longer needed them, which *must*
>>>> mean that they had some other defence.
>
>Robust australopiths lost their projecting canines (though they still showed
>butressed maxillae for the canines). That means that projecting canines had
>more disadvantages than advantages. The primary use of canines (at least in
>females) is dietary.
This is almost certainly wrong. There is far too much variation
in diet among primates, yet they all have large canines. Males
may often have larger ones, because they fight more and defend
their troops against each other and against predators. But
females often fight; they need to defend themselves from attack.
Female chimps dominate all juveniles. Two or female chimps will
defeat a single male; but this would be impossible without their
canines.
>Projecting canines must have hindered chewing. This
>fits the (almost) completely herbivorous diet of the robusts as shown by
>their thick enamel, enamel microwear, huge (pre)molar & cheekbone size.
If you can find no other animal with teeth like that, you have no
idea what the diet was. Herbivorous animals don't have such
teeth.
>I think we may assume that australopiths were about as strong & agile as,
>say, chimpanzees. If the danger came from the water (crocodiles...) they
>fleed to the trees (at least the graciles) or to the land (large canines
>were of no use).
Very few, if any, species have such an easy life. They have to
forage where there are no trees, or in the water, or in a marsh
or whatever.
>If the danger came from the land (leopards...) they fleed
>to the water or to the trees, where they were more agile than leopards.
The danger from leopards comes at night, when primate agility is
nearly useless.
>How do gorillas manage?
Gorillas manage with difficulty. They fear leopards -- and will
leave "fear dung" on sites where they have been under threat
during the night. The large male stays at the bottom of the
tree, presumably in order to protect his family.
>I think you must not overemphasize the
>worth of canines against leopards (the strong arms were probably more
>important).
Canines are the equivalent of knives. Any woodsman will tell you
how vital it is to have a knife. Someone who fights with a knife
will always beat someone without.
>The use of canines against other males (display, attack, defence) is the
>same in both fighters. If the dietary disadvantages of long canines
>outweighted the intraspecific advantages, long canines gradually shrunk, &
>vice versa. (If you starve though you can beat all other males, your long
>canines are of no use.)
But if you can beat all other males, you won't starve. You'll
get the resources. Or to put it another way, if all males can
beat you, you'll get nothing. This is why animals (and, perhaps,
nations) could not afford to lose their weapons -- unless they
replaced them with better ones. If that restricts their diet (or
economy) so be it.
>Of course, if you already possess large canines (for eating), you no doubt
>use them also for defending yourselve.
That is not the way the world works, as Mao, Stalin, Hitler or
any major historical leader would have told you.
>(what is AFAIK?)
As Far As I Know
>>The main changes were bipedalism, the acquisition of hands
>>designed to grasp, and the loss of large canines. These fit far
>>too well with club wielding for it not to be the main hypothesis.
>
>In an evolutionary perspective I think you have to explain all features
>independently.
This is utterly wrong. The features relate to a niche that the
animal discovered. When you look at other species, you always
explain their existence from their features taken as a whole.
>- striding bipedalism in primates is always wading (& gibbons walking along
>branches perhaps)
>- grasping hands cf. monkeys & apes
>- fine manipulation in Homo cf. racoons & otters (& in robusts cf. perhaps
>bamboo bears)
>- loss of projecting canines in australopiths esp. robusts: herbivorous
>- in Homo (in Sangiran still "more powerful canine", Rensch 1972 "H.sapiens"
>Columbia UP): use of stones instead of canines? (or problems for suction?)
>Paul, I think you make the same mistake as the savanna people who want to
>link bipedality & nakedness & transipiration etc.
They are right in that respect. Sweating would work poorly
without nakedness; nakedness does not work for clinging infants;
bipedalism does not go with clinging infants; bipedalism
requires altricial infants; manipulative hands require
bipedalism; the absence of canines requires manipulative hands;
the use of clubs requires bipedalism; sweating requies good
supplies of water and salt; the absence of canines requires the
use of clubs; bipedalism requires the use of clubs; and so on.
They are all inter-linked. Any proposed niche has to enable and
acount for_every_ single_one_of_them, as well as accounting for
the hard teeth and the factor that forced infant altriciality.
The only trouble with any savanna theory is that it has to ignore
some of these elements.
Paul.
Paul Crowley
>No evidence of vit.A poisoning in hominid fossils! This solution was
>"invented" because they could find any better.
>(The thick bones can only be explained by slow diving.)
This is quite wrong. See Alan Walker's "The Wisdom of Bones".
The bones of KNM-ER 1808 and the Seveso hominid had a
pathological layer which was quite unlike normal bone. When they
were found they were not even identified as hominid bone.
>> you need to explain why all primates, other than us,
>>possess them, considering they have an enormous range of diets.
>
>Gigantopith. had small canines. Somo Sivapith. "ramapiths" had small
>canines. Hapalemur (bamboo lemur) has small canines (not much longer than
>its incisors & much shorter than Lemur). Some believe Gigantopith. ate a lot
>of bamboo.
There may be some slight exceptions to the rule (all primates
have large canines). You still need to explain it.
>>Imagine us re-growing large canines! We would _first_ have to change our
>method of mastication. Why on earth would we?
>
>The australopiths (very clear in africanus) still had buttressed maxillae
>for the canines.
So do we -- after four or so million years with canines the same
size as incisors, our canine roots are still much deeper. Go to
a mirror and have a look at your gums.
>>As you well know, changes in dentition are extraordinarily slow
>>in all taxa. They are distinctive to orders, families and
>>genera. Your disregard of the permanence of their nature is
>>cavalier.
>
>("cavalier"? horse-rider?)
Cavalier as in supporters of Charles I of England: "showing a
haughty disregard". You need a good English dictionary. Thank
God Dutch is not the language of the internet.
>How do you know the australopiths had no ischial callosities?
Since ancestors and descendants don't, and since larger apes
don't sleep sitting up; it's a reasonable assumption.
>What is CA?
As LCA (Last Common Ancestor) without the L.
>Is Kanzi a male?
Yes.
Paul.
Paul Crowley
On Mon, 1 Jun 1998 12:07:11 GMT, dba...@liv.ac.uk (Dan Barnes)
wrote:
>> Another vitamin-A-poisoned fossil was found at Venosa in
>>Italy dated to about 0.5 mya.
>>
>Paul I'm curious where you got the info on Venosa from. I've read a lot about the
>fossil but I don't recall mention of vitamin A poisoning (which of course doesn't
>mean its not mentioned). If you could tell me which of these papers it is
>mentioned in it'll help narrow down the search:
This was my source (although the authors believe that the
pathological deposits were caused by Yaws).
>Similar bone deposits on an
>H. erectus femur dated ca. 500,000 years ago from Venosa, in
>southern Italy, suggest that when early humans spread out from
>Africa they took yaws with them.--MARK ROSE
>
> C 1996 by the Archaeological Institute of America
>
>http://www.archaeology.org/9605/index.html
>Also Paul I'm never sure how serious you are
I think I'm usually fairly serious.
>but the evidence at Notarchirico
>(Venosa) shows that the hominids were entering the area around Mount Vulture
>immediately after a volcanic eruption and exploiting the dead animals there.
I hate an explanation centered around a few days. It requires
almost uncontrovertible evidence to support it.
>I can't think of any archaeological evidence in the
>Palaeolithic for dog eating
It would have been only marginally more common than in historical
times -- only when desperate circumstances forced it. Otherwise
the hominids would have known to avoid the liver.
Paul.
Dwight E. Howell
> Orangs do have fossilised probable relatives: Sivapithecus &
> Gigantopithecus.
>
True but they are not African.
> >Still the info will be found given enough time. I agree that the
> >ancestors of African apes may have been more erect than they are but
> >don't care to claim that they were fully developed bipeds.
>
> IMO the australopiths were no "full" bipeds. They waded a lot to get
> their
> food (sedges, reed...), walked bipedally on dry land, climbed in trees
>
> (where the graciles must have been very agile), & possible swam a lot
> (probably lumbar lordosis, full plantigrady...), but they were no
> long-legged exclusive bipeds like we.
>
Excuse me, but the books I have read on the topic make it very, very
clear that Lucy and her kin were just as much bipeds as any modern human
if rather on the short legged side. There are some functional
differences but nothing that changes the above statement.
> >
> >The problem to me is that the split seems to be to closely dated in
> >time to the known bipeds. I'm starting to wonder if more than one
> later
> >group may have become bipeds and maybe some of the earliest known are
>
> >cousins at best. It is strange that several lines of descent should
> >appear at about that time leading to apes and man from one rather
> >unknown animal while a host of other equally promising creatures went
>
> >poof.
>
> (what promising creatures do you mean? fossils? "went
> poof"=disappeared?)
>
I mean that the non Homo bipeds seem to have been very diverse but
everything else that might have existed at the time seems to have
vanished leaving use with a few ape lines most notable for their lack of
a fossil record.
> Molec.data suggest the LCA of Homo/Pan/Gorilla lived ca.6 mya.
> Fossils from Europe/Turkey (Ourano-Graeco-Ankarapith.) suggest close
> relatives of hominids+ponigds might have lived in the Middle East
> ca.10 mya
> (eg, Algaput etc.1996 "A new species of Ankarapith.meteai from...
> central
> Anatolia" Nat.382:349).
> >
> >The other question is which of these groups were species? They are
> >diverse enough to have been many especially when you look at how
> similar
> >modern African apes are and yet can't cross breed but if so why are
> all
> >the moderns derived from this single source?
>
> We have the molecular data of splitting times:
> - hominids=Pan+Homo+Gorilla / pongids=orang between 13-8 mya
> - Gorilla /Homo+Pan between 5-8 mya
> - Homo / Pan between 4-6 mya
> - bonobo / common chimp ca.2 mya?
> - western / eastern gorilla ca.2 mya?
> - Pan troglodytes / verus ca.1.4 mya??
> - Homo Africa / rest (or KhoiSan / rest?) 200-100,000 ya?
>
We know that living organisms had ancestors. We don't know which fossils
have decedents nor how closely any fossils were related to any other.
> All australopiths no doubt belonged to the hominids (living members:
> Pan,
> Homo, Gorilla). CE.Oxnard believes they did not belong Pan or Homo or
> Gorilla, but to an other extinct hominid clade. Most anthropologists
> believe
> australopiths were closer relatives of Homo than of Pan or Gorilla.
> IMO
> africanus & robustus belonged to Pan, aethiopicus & boisei belonged to
>
> Gorilla, see my papers:
>
When somebody finds some fossils that suggest this I want to be the
first to congratulate you but until then this is just another hypothesis
or w.a.t.
Your only real problem is a lack of evidence. What the evidence will
show when it is found is anybody's guess. Until then yours is as good as
anybody else's but no better.
> 1990. African ape ancestry. Hum.Evol.5, 295-297.
> 1994. Australopithecines: ancestors of the African apes? Hum.Evol.9,
> 121-139.
> 1996. Morphological distance between australopithecine, human and ape
> skulls. Hum.Evol.11, 35-41.
> 1997. In den Beginne was het Water. Nieuwste Inzichten in de Evolutie
> van de
> Mens. Hadewijch, Antwerpen.
>
> Marc
>
> >I guess I saying that one or more of the African apes should
> logically
> >be a lot less closely related than they are. Or maybe the apes are
> just
> >loosing niches to the monkeys but even this doesn't seem to explain
> the
Dwight E. Howell
> It would have been only marginally more common than in historical
> times -- only when desperate circumstances forced it. Otherwise
> the hominids would have known to avoid the liver.
>
> Paul.
I thought you said you hated explanations that centered on short term
events.
If you eat your dog you may die of vitamin poisoning but it won't show
on fossil bones. That would only occur if you ate dog on a regular bases
for some time so that the condition could become chronic before you
died. Most likely weeks or months. How many dogs do you feel these
people had?
Norman K. McPhail
Norman K. McPhail wrote:
>
> Jim McGinn wrote:
> >
> > Norman K. McPhail wrote in message <356F12...@socal.wanet.com>...
> > >Jim McGinn wrote:
>
> > >> Norman K. McPhail wrote in message <356DD0...@socal.wanet.com>...
> > >> >Jim McGinn wrote:
>
> > >> >> Norman K. McPhail wrote in message <356C9B...@socal.wanet.com>...
> > >> >> >Paul Crowley wrote:
>
> > >> >> >> On Tue, 26 May 1998 16:52:51 -0700, "Jim McGinn"
> > >> >> >> <jimm...@msn.com> wrote:
>
> > >> >> >> >>Paul Crowley heeft geschreven in bericht
> > >> >Norm wrote:
> > >Most of us now grasp the fact that we humans have bent some of the > > >laws of nature.
Then Jim responded:
> > No way.
Are you suggesting here that because some of the laws of physics may be
the
same today as they were prior to the appearance of homo sapiens that we
humans
could not have bent the rules of biological change? If so, this infers
that
the laws of physics are deterministic with respect evolutionary
processes. In
other words, you seem to be saying that since the laws of physics
probably
haven't changed much in the last two or three million years, it is
impossible
for genetics to have changed during that period of time.
In response to this claim, I would ask you to go back about three or
four
billion years. Consider what seems to have happened here on earth. So
far as
we know, the lifeless seas of the proto biosphere saw the emergence of
what we
now call life.
For some still unknown reason, most of us think that about 3.5 million
years
ago, life came through the mix of lifeless conditions here on earth.
You
might note that what we refer to as the laws of physics were probably
the same
before the emergence of life as the were after it appeared. Would you
like to
claim that since these laws of physics did not change, that life did not
appear?
If not, I would ask if you still want to claim that the rules that guide
life's changing processes couldn't change without there first being a
change
in the laws of physics? Surely, the emergence of life itself was a much
bigger change than the rule changes I was referring to. So I will stand
by my
claim that we humans used thought to bend the rules of variation and
selection
that help make up what we call evolution.
Dwight E. Howell
Marc Verhaegen wrote:
I don't feel that the idea that they may have fished for termites, eaten
grubs and maybe lizards, and any baby or small unlucky animal they could
catch as do modern chimps would in any way conflict with the above
statement as to the foundation of the diet of these creatures. Even if
some cracked the long bones found in abandoned kills and ate the marrow
I don't feel that any evidence would show in the wear pattern of the
teeth nor that any selection for another type of tooth would appear.
I will repeat something I have read but cannot confirm to be true. The
later Robustus had somewhat smaller tooth size, skull crests, and larger
brain size than many of the older ones. Someone else may be able to
provide an update on this view. My source is now several years out of
date.
Jim McGinn
Norman K. McPhail wrote in message <357424...@socal.wanet.com>...
>Norman K. McPhail wrote:
>>
>> Jim McGinn wrote:
>> >
>> > Norman K. McPhail wrote in message <356F12...@socal.wanet.com>...
>> > >Jim McGinn wrote:
>>
>> > >> Norman K. McPhail wrote in message <356DD0...@socal.wanet.com>...
>> > >> >Jim McGinn wrote:
>>
>> > >> >> Norman K. McPhail wrote in message
<356C9B...@socal.wanet.com>...
>> > >> >> >Paul Crowley wrote:
>>
>> > >> >> >> On Tue, 26 May 1998 16:52:51 -0700, "Jim McGinn"
>> > >> >> >> <jimm...@msn.com> wrote:
>>
>> > >> >> >> >>Paul Crowley heeft geschreven in bericht
>[snip]
>> > >> >Norm wrote:
>
>> > >Most of us now grasp the fact that we humans have bent some of the > >
>laws of nature.
>
>
>Then Jim responded:
>
>> > No way.
>
>
>Are you suggesting here that because some of the laws of physics may be
>the
>same today as they were prior to the appearance of homo sapiens that we
>humans
>could not have bent the rules of biological change? If so, this infers
>that
>the laws of physics are deterministic with respect evolutionary
>processes. In
>other words, you seem to be saying that since the laws of physics
>probably
>haven't changed much in the last two or three million years, it is
>impossible
>for genetics to have changed during that period of time.
yes.
>
>In response to this claim, I would ask you to go back about three or
>four
>billion years. Consider what seems to have happened here on earth. So
>far as
>we know, the lifeless seas of the proto biosphere saw the emergence of
>what we
>now call life.
>
>For some still unknown reason, most of us think that about 3.5 million
>years
>ago, life came through the mix of lifeless conditions here on earth.
>You
>might note that what we refer to as the laws of physics were probably
>the same
>before the emergence of life as the were after it appeared. Would you
>like to
>claim that since these laws of physics did not change, that life did not
>appear?
The properties changed. The laws didn't.
I consider life to be a property of matter that is dependent on conditional
factors.
Would you say that the laws of physics are different on Mars than they are
on Earth and that's why Mars doesn't have life? Of course you wouldn't.
As a scientist you have to assume that laws are unchanging and immutable.
It comes with the territory. If you can prove that they are then they are
no longer laws.
>
>If not, I would ask if you still want to claim that the rules that guide
>life's changing processes couldn't change without there first being a
>change
>in the laws of physics? Surely, the emergence of life itself was a much
>bigger change than the rule changes I was referring to. So I will stand
>by my
>claim that we humans used thought to bend the rules of variation and
>selection
>that help make up what we call evolution.
Unless you can describe the circumstances as to how we "bent the rules of
variation" what your saying is both vague and speculative. It doesn't
really tell us anything. It doesn't solve the problem.
Paul Crowley
>> It would have been only marginally more common than in historical
>> times -- only when desperate circumstances forced it. Otherwise
>> the hominids would have known to avoid the liver.
>If you eat your dog you may die of vitamin poisoning but it won't show
>on fossil bones. That would only occur if you ate dog on a regular bases
>for some time so that the condition could become chronic before you
>died.
I see what you are saying, but this is not the opinion of the
medical experts that Alan Walker asked to investigate KNM-ER
1808. Vitamin-A poisoning dislodges the material that sheaths
the long bones. The body's reaction to this is to bleed into
those gaps, and cause the bones to grow very rapidly into that
space, forming material with a strange disaggregated structure,
which would be quite incapable of bearing weight. All this is
exceedingly painful and incapacitates the victim. And this is
only one of the many painful symptoms. You have headaches and
nausea, stomach cramps, and aching muscles and bones; your skin
peels off in strips. Your gums bleed and your teeth start to
fall out. So someone in this condition is unlikely to live long.
It seems to be necessarily acute rather than chronic.
Also if you got this reaction from eating dog liver on two or
three occasions, and lived, you'd never eat it again. The only
people who do so are in desperate circumstances and become too
ill to know what they are doing.
Paul.
Jim McGinn
Philip Deitiker wrote in message <35732f9c.25089657@news>...
>On Mon, 01 Jun 1998 11:27:52 -0700, "Norman K. McPhail"
><no...@socal.wanet.com> wrote:
>>
>>In the context of the topics discussed in this news group, is there any
>>consensus about what the terms relativist and absolutist mean?
>
The context that I intended the terms is not specific to the subject of
human evolution. It has to do with problems in the philosophical
underpinnings of how we percieve causative processes in evolutionary theory
in general. As it relates to the topic of human evolution it involves
achieving a definition of fitness that allows for the evolution of the kind
of altruism that we see in humans.
Science works best (gives us useful information) when it is measured in
discreet units. Biological phenomena simply does not conform to such. As a
result biologist have made a number of assumptions about what these units
are or should be, ie, what is or is not an entity, what is or is not a
quality of an entity, how big and for how long does the causation produced
by an entity continue into time. Invariably the choices that have been made
by biologists with respect to these assumptions have more to do with what is
comfortable than they do with how causative processes of biological
phenomema really are. In the end we end up with definitions of terminology,
eg. fitness, that are more useful to those who have less than altruistic
agendas, ie eugenics and the like, than it is to those trying to solve
problems, ie. the cause of human evolution.
Another consequence that more specifically relates to human evolution is
that many people have used the highly innaccurate understanding of fitness
(its innacuracy being the result of the absolutistic assumptions contained
therein) to come to the conclusion that human evolution could not have
happened without some sort of intervention from God, or extraterrestrials.
>I have no idea what the aforementioned personal debate is about;
>however relative vs. absolute are easily defined.
Reality is relativistic. This can be proven simply enough. The terminology
we use is usually absolutistic (and for reasons based on the practical ends
to be achieved by their *normal* usage it is good that they are
absolutistic). It is extremely difficult to define terminology in a manner
that accurately reflects relativistic realities. Moreover terminology that
accurately reflects these relativistic realities is much more cumbersome to
use. Very few people have the patience or the inclination to deal with the
difficulties associated with such. It is normal to just define absolute and
then dismiss it as being unimportant.
In short: it may be easy to define relative and absolute but it is extremely
difficult to redefine terminology in a manner that accurately reflects
relativistic realities. I have done so. And it has been extremely
rewarding with respect to allowing me to achieve an understanding of
causative processes in evolutionary theory that allows me to get beyond the
absolutist assumptions and the sometimes ridiculous (often evil) conclusions
that, ultimately, find their philosophical basis in absolutistic
assumptions.
>An absolute
>perspective is based upon a firm boundary, for example kelvin is based
>on temperature above the lowest possible temperature (O'k) at which
>temperature molecules lack vibrational motion.
The firmness of a boundary is not absolute. It can only be more firm or
less firm than another boundary.
>Celcius and Farenhiet
>are basen on the temperatuer relative to frozen water and saline
>respectively. The scale in all three systems is relative, in K and C
>its relative * 100 to the freezing/boiling temps of water (and again
>boiling point is relative to atmospheric pressure). There are few
>things that are absolute.
There are no things that are absolute. However saying this and designing
terminology that prevents us from the normal human inclination to assume the
existence of absolutes are two different things. The first is easy. The
second is extremely difficult.
>For example there are no absolute centers of
>reference for either position, speed, or acceleration. This was
>brought up by einstein. One could argue the universe is centered
>around the unit of expansion, but roughly speaking in the space time
>continuoum its very difficult to say where that position is in useful
>units (which right now is about 10E-10M). Even if one could do this,
>it would only be good for that moment.
>
>>What does it mean to be an absolutist with respect to the various
>>alternative sequences for the evolution of apes and homo in Africa?
As I mentioned above it really has no direct relevance to such.
>
>Defining that the 7 million years of seqeunce would be restricted to
>africa would be an unjustifyably absolutist perspective.
No direct relevance.
>
>>Does an absolutist demand some special form of physical evidence? Or do
>>they just disagree as to what constitutes physical evidence?
No direct relevance.
>
>Like a reasonably complete skeleton, or a skeleton at varying sizes
>druing development and of both sexes, and associated with cultural
>artifacts which give insight into intelligence.
No direct relevance.
>
>>Since this evidence can sometimes be reasonably interpreted in several
>>ways, don't even the absolutists try to relate all aspects of the
>>evidence we can gather into a plausable scenario? Isn't this of
>>necessity relational? And, at least for now, aren't all the ideas they
>>put forth speculative to some degree?
>
>>So can't both relativists and absoltutists speculate and guess what all
>>the data we have means? If this is the case, what then is the
>>difference between those who call themselves relativists like Jim McGinn
>>and those who think of themselves as absolutists?
The difference is simply a matter of achieving scientific accuracy with
respect to causative processes in biological phenomena.
>
>Sticks and stones.
>
>I might point out that there is no absolute way of knowing which
>artifacts represents those specimens which were part of our anscestral
>lineages and which were not, as one goes back in time the problem gets
>even worse, and most probably the best guesses of today are wrong.
I agree. With respect to human evolution I am unconcerned with any of the
evidence that happened after that point 4 to 5 million years ago when our
chimpanzee-like ancestors first began the process of human evolution. I
think that all of the evidence inbetween that point and the present is bound
to be misleading. Simply put, human evolution did not happen as a result of
phases or multiple habitats. Something very specific happened 4 to 5
million years ago that put our species on an evolutionary path that is
completely unique when compared to any other species.
Jim McGinn
Marc Verhaegen
Dwight E. Howell heeft geschreven in bericht <35739657...@usit.net>...
>> Orangs do have fossilised probable relatives: Sivapithecus &
>> Gigantopithecus.
>>
>True but they are not African.
Has that anything to do with it? Can't A.boisei stand to Gorilla as
Gigantopith. stands to Pongo?
...
>> IMO the australopiths were no "full" bipeds. They waded a lot to get
their
>> food (sedges, reed...), walked bipedally on dry land, climbed in trees
>> (where the graciles must have been very agile), & possible swam a lot
>> (probably lumbar lordosis, full plantigrady...), but they were no
>> long-legged exclusive bipeds like we.
>>
>Excuse me, but the books I have read on the topic make it very, very
>clear that Lucy and her kin were just as much bipeds as any modern human
>if rather on the short legged side. There are some functional
>differences but nothing that changes the above statement.
The popular books, yes, they repeat each other.
Perhaps you better read, eg, JT Stern & RL Susman 1983 Locomotor anatomy of
A.afarensis. AJPA 60:279
Australopith postcranials are sometimes intermediary between humans & apes,
sometimes unique (see esp. the studies of the engineer CE Oxnard).
>I mean that the non Homo bipeds seem to have been very diverse but
>everything else that might have existed at the time seems to have
>vanished leaving use with a few ape lines most notable for their lack of
>a fossil record.
Not lack IMO (& in the opinion of many others):
Australopithecine ancestors of African apes?
Marc Verhaegen
Palaeo-anthropological data do not exclude the possibility that not only
humans but also chimpanzees and gorillas could have had
australopithecine-like ancestors. In fact, the traditional hypothesis – that
all australopithecines are closer relatives of humans than of chimps or
gorillas – has serious difficulties:
a. The apparent absence or extreme rarity of fossil ancestors or relatives
of any African ape is puzzling.
b. Various australopith-like features are present in premature but not in
adult African apes (e.g. relative orthognathy, less dorsal foramen magnum,
more orthogrady).
c. Australopiths lack the uniquely derived features that set Homo, at least
since erectus, apart from nonhuman primates (e.g. external nose, very large
brain, very long legs), and generally resemble the apes.
d. At the time of the robust australopiths there already lived more
humanlike creatures like KNM-ER 1470.
The Laetoli footprints A and G suggest that australopithecines were partly
or fully bipedal. Bipedalism is generally considered to be the defining
feature of the hominids, which links australopiths with humans. But the
African apes’ locomotion is unique - plantigrady plus knuckle-walking - and
is easily derivable from the kind of “short”-legged plantigrade bipedalism
that is frequently seen in lowland gorillas wading in shallow waters and
occasionally in all African apes. If the African apes had more bipedal
ancestors, there is every reason to include them into the hominids – in
agreement with the comparative molecular evidence of DNA and proteins.
...
...
>> All australopiths no doubt belonged to the hominids (living members: Pan,
>> Homo, Gorilla). CE.Oxnard believes they did not belong Pan or Homo or
>> Gorilla, but to an other extinct hominid clade. Most anthropologists
believe
>> australopiths were closer relatives of Homo than of Pan or Gorilla.
>> IMO africanus & robustus belonged to Pan, aethiopicus & boisei belonged
to
>> Gorilla, see my papers:
>>
>
>When somebody finds some fossils that suggest this I want to be the
>first to congratulate you but until then this is just another hypothesis or
w.a.t.
>
>Your only real problem is a lack of evidence. What the evidence will
>show when it is found is anybody's guess. Until then yours is as good as
>anybody else's but no better.
Well, there are curiously detailed resemblances, eg:
- boisei~gorilla: extreme size & dimorphism, orbital shape, enamel prism
decussation
- robustus~chimp: intrapalatal sinus maxillaris
Marc
Marc Verhaegen
Paul Crowley heeft geschreven in bericht
Of course, we have excellent comparative evidence (see esp. b&c):
Wetland apes: hominid palaeo-environment and diet
Marc Verhaegen & Pierre-François Puech - UMR 6569 du CNRS - Faculté d’
Odontologie de Marseille - France
The combination of the available evidence from different anthropological
researches makes it clear that hominid evolution did not begin in warm and
dry but in warm and wet conditions.
a. No feature typical of savannah mammals is found in humans: low need of
drinking-water or succulent food; concentrated urine; tolerance of
dehydration and radiation heat; high diurnal body temperatures and daily
temperature fluctuations; high velocities; digiti/unguligrady; poorly
developed vocalisations and dexterity...
b. Comparative studies of cheekteeth microwear suggest that the australopith
diet included marshland plants (PF Puech). In afarensis, the enamel has a
polished surface (cf. mountain beaver, capybara: sappy aquatic herbs and
grasses, buds and bark of young trees). In boisei, it displays more pits,
wide parallel striations and deep recessed dentine (cf. beaver: aquatic
plants, bark, more woody parts). In habilis, the margins of the striae have
been polished and slightly etched (cf. coypu: reed, sedges, marsh plants,
fruits, molluscs).
c. Robust australopiths resemble reed/bamboo-eaters in front teeth reduction
and cheekteeth broadening (cf. gentle lemurs, giant panda, EL DuBrul), and
estimates of the robusts’ bite force also suggest “low-energy food… to be
processed in large quantities… hard and round in shape” (B Demes & N Creel).
d. The low Sr/Ca ratios in Swartkrans robusts have been explained by partial
carnivory (unlikely with their herbivorous dentition), eating leaves and
shoots of forbs and woody plants (cf. kudu) and eating food from wet,
well-drained streamside soils (A Sillen).
e. Palaeo-ecology indicates that early australopithecines lived in warm,
humid and often forested landscapes. Robust australopiths dwelt near more
open environments like grasslands, marshlands and lagoons. Homo species are
frequently found near ancient lakes, seas and rivers where molluscs were
abundant.
It seems that early australopiths were bipedal frugi/herbivores in forest
clearings (cf. western gorillas eat sedges, wading in shallow waters, D
Chadwik). The robusts later ate marshland plants like papyrus, reed, nuts
etc. Early Homo used stones to crack nuts and shellfish (cf. mangrove
capuchins, M Fernandes). This would explain stone tool use for other
purposes, the rapid spread to SE Asia, and the increase in brain size (SC
Cunnane).
>
>>I think we may assume that australopiths were about as strong & agile as,
>>say, chimpanzees. If the danger came from the water (crocodiles...) they
>>fleed to the trees (at least the graciles) or to the land (large canines
>>were of no use).
>
>Very few, if any, species have such an easy life. They have to
>forage where there are no trees, or in the water, or in a marsh
>or whatever.
>
>>If the danger came from the land (leopards...) they fleed
>>to the water or to the trees, where they were more agile than leopards.
>
>The danger from leopards comes at night, when primate agility is
>nearly useless.
>
>>How do gorillas manage?
>
>Gorillas manage with difficulty. They fear leopards -- and will
>leave "fear dung" on sites where they have been under threat
>during the night. The large male stays at the bottom of the
>tree, presumably in order to protect his family.
If I were a leopard I would think twice before attacking a male boisei.
>
>>I think you must not overemphasize the
>>worth of canines against leopards (the strong arms were probably more
>>important).
>
>Canines are the equivalent of knives. Any woodsman will tell you
>how vital it is to have a knife. Someone who fights with a knife
>will always beat someone without.
(You're comparing a leopard that can't afford to be hurt & a gorilla or
boisei that will fight for its life.)
>
>>The use of canines against other males (display, attack, defence) is the
>>same in both fighters. If the dietary disadvantages of long canines
>>outweighted the intraspecific advantages, long canines gradually shrunk, &
>>vice versa. (If you starve though you can beat all other males, your long
>>canines are of no use.)
>
>But if you can beat all other males, you won't starve. You'll get the
resources.
No, that's the point: they had to chew & chew sedges & reeds etc. (very poor
diet).
>Or to put it another way, if all males can
>beat you, you'll get nothing. This is why animals (and, perhaps,
>nations) could not afford to lose their weapons -- unless they
>replaced them with better ones. If that restricts their diet (or
>economy) so be it.
>
>>Of course, if you already possess large canines (for eating), you no doubt
>>use them also for defending yourselve.
>
>That is not the way the world works, as Mao, Stalin, Hitler or
>any major historical leader would have told you.
>
>>(what is AFAIK?)
>
>As Far As I Know
>
>>>The main changes were bipedalism, the acquisition of hands
>>>designed to grasp, and the loss of large canines. These fit far
>>>too well with club wielding for it not to be the main hypothesis.
>>
>>In an evolutionary perspective I think you have to explain all features
>>independently.
>
>This is utterly wrong. The features relate to a niche that the
>animal discovered. When you look at other species, you always
>explain their existence from their features taken as a whole.
Of course, but you can understand all their features apart!
(Evolution works in parallel on all those different features. The
individuals with the best combinations with survive.)
>
>>- striding bipedalism in primates is always wading (& gibbons walking
along
>>branches perhaps)
>>- grasping hands cf. monkeys & apes
>>- fine manipulation in Homo cf. racoons & otters (& in robusts cf. perhaps
>>bamboo bears)
>>- loss of projecting canines in australopiths esp. robusts: herbivorous
>>- in Homo (in Sangiran still "more powerful canine", Rensch 1972
"H.sapiens"
>>Columbia UP): use of stones instead of canines? (or problems for suction?)
>
>>Paul, I think you make the same mistake as the savanna people who want to
>>link bipedality & nakedness & transipiration etc.
>
>They are right in that respect. Sweating would work poorly
>without nakedness
No, the most abundant sweaters (on their naked hindflippers) are overheated
furseals on land.
> nakedness does not work for clinging infants;
long head hairs
swimming lifestyle
>bipedalism does not go with clinging infants
?? kangaroos
(& wading gorillas in Congo Brazzaville forests)
> bipedalism requires altricial infants
??
> manipulative hands require bipedalism;
racoons
> the absence of canines requires manipulative hands;
most herbivores
>the use of clubs requires bipedalism;
chimps
> sweating requies good supplies of water and salt;
(water yes, it gives the cooling, but salt?)
so what?
>the absence of canines requires the use of clubs;
horse?? capibara?? etc.
bipedalism requires the use of clubs; and so on.
kangaroo
>They are all inter-linked....
They are "inter-linked" because they exist in humans! Post hoc ergo propter
hoc.
Marc
Jim McGinn
NK...@my-dejanews.com wrote in message <6l4s0m$4vv$1...@nnrp1.dejanews.com>...
>Jim McGinn wrote:
>>
>> Norman K. McPhail wrote in message <357424...@socal.wanet.com>...
>> >Norman K. McPhail wrote:
>> >>
>> >> Jim McGinn wrote:
>> >> >
>> >> > Norman K. McPhail wrote in message
<356F12...@socal.wanet.com>...
>> >> > >Jim McGinn wrote:
>> >>
>> >> > >> Norman K. McPhail wrote in message
<356DD0...@socal.wanet.com>...
>> >> > >> >Jim McGinn wrote:
>> >>
>> >> > >> >> Norman K. McPhail wrote in message
>> <356C9B...@socal.wanet.com>...
>> >> > >> >> >Paul Crowley wrote:
>> >>
>> >> > >> >> >> On Tue, 26 May 1998 16:52:51 -0700, "Jim McGinn"
>> >> > >> >> >> <jimm...@msn.com> wrote:
>> >>
>> >> > >> >> >> >>Paul Crowley heeft geschreven in bericht
>> >[snip]
>> >> > >> >Norm wrote:
>> >[snip]
>> >> > >Most of us now grasp the fact that we humans have bent some of the
> >
>> >laws of nature.
>> >
>> >
>> >Then Jim responded:
>> >
>>
>> Unless you can describe the circumstances as to how we "bent the rules of
>> variation" what your saying is both vague and speculative. It doesn't
>> really tell us anything. It doesn't solve the problem.
>
>
>First take note that I said we humans "bent" the rules. In some ways, we
>intend to bend these rules for our own benefit. In other ways, we
>unintentionally bend the rules that can harm us individually and perhaps as
a
>species.
>
>These latter changes include the spreading of thousnads of chemical
compounds
>not previously found in the wild. This not only increases variations in
many
>cases, it can and is proven to significantly alter the ecological balance.
>Many species go completely extinct, some teeter on the brink of oblivion.
>
>Add to this the physical demolition of many habitats throughout the world
and
>we begin to get a significant change in the make up of the biosphere. On
top
>of these changes, changes in the composition of the atmosphere seem to be
>contributing to indirect changes in habitats. We are probably also causing
>changes in temperatures, rainfall, soil, ocean currents and other
interrelated
>components of the biosphere.
>
>We transplant species into ecosystems where they wipe out isolated species
>whose gene's can't change them fast enough to compete. We breed and
protect
>all kinds of plant and animal species that are useful to us. Some of these
>cause major disruptions and discontinuities amongst what some call the
native
>ecosystems.
>
>Isn't it just a diversionary tactic to argue that all these changes are
>natural? The point is that we need to continue to press our effort to
>understand as much as we can about what we are doing and what this could
mean
>in the years and eons to come.
>
>Surely you are not suggesting that we are immune to all these changes we
are
>causing in our surroundings. And surely you are not suggesting that we
ought
>not to make every effort to understand our selves, each other and the world
we
>live in. I can't imagine that you would advocate anything other than an
all
>out effort to understand and sustain a diverse and healthy biosphere that
will
>support our descendants in the future.
>
>More to the point about how our relationship with the environment differs
from
>other species, we humans use our brains to encode the ways our surroundings
>work. We make mental models of ecosystems and how they work. Then we
>intervene where it suits our needs and purposes.
>
>The difference between a gopher's hole and a house a group of humans might
>build for themselves has to do with this question of coding. It is related
to
>the coding differences between RNA and DNA. The RNA coding is built into
the
>molecules in ways that limit the products of the replicating process. DNA
on
>the other hand, uses a coding system that opens up a limitless number of
>variations on the replicating processes.
>
>Somehow our forebears' brains developed the ability to encode some of the
>workings of their surroundings in what some refer to as symbols. This
>symbolic coding added another layer of data that gave them a way to change
the
>things around them. Thus our forebears learned to change their
surroundings
>instead of having to wait until their surroundings changed them.
>
>If you want to argue that this did not change the rules of gene warfare,
>that's your right and privilege. But I say that this way of using their
>brains to process data is of a different logical type than the way DNA
>processes data. I think these differences are as great as the differences
>between DNA data processing and the way lifeless chemicals process data.
>
>Note that there is no vitalism here. We are dealing with well established
>scientific differences. I am just putting them into what I think is a more
>authentic frame of reference.
>
>-----== Posted via Deja News, The Leader in Internet Discussion ==-----
>http://www.dejanews.com/ Now offering spam-free web-based newsreading
For the most part I'm sympathetic to what your saying here. Or at least I'm
sympathetic in spirit if not always in fact. Where we differ is with
respect to interests. My main interest is the cause of human evolution.
Much of what you say here is very valuable. But from what I can tell it
doesn't seem to have any implications on the topic that I am most concerned
with, the cause of human evolution.
Jim McGinn
Norman K. McPhail
[snip]
Jim wrote:
Where we differ is with
> respect to interests. My main interest is the cause of human evolution.
> Much of what you say here is very valuable. But from what I can tell it
> doesn't seem to have any implications on the topic that I am most concerned
> with, the cause of human evolution.
My main interest is in understanding who and what we are. Of course,
"...the cause of human evolution" is central to who and what we are.
Still, understanding our selves, each other ahd the universe we live in
is what fascinates me most. The key to this understanding is
understanding what our understanding is and how we got it.
As you can see from DOHU, more specific insights into how and why our
forebears became generalists would help anchor and refine some of the
basic assumptions. So I look forward to learning more about your ideas
of what happened about 4mya that helped propel them into what I call
symbolic thought and human understanding.
Jim McGinn
no...@socal.wanet.com wrote in message <6l4sgc$5r8$1...@nnrp1.dejanews.com>...
>Jim McGinn wrote:
>>
>> Norman K. McPhail wrote in message <357360...@socal.wanet.com>...
>> >Jim McGinn wrote:
>> >>
>> >> Norman K. McPhail wrote in message <356F12...@socal.wanet.com>...
>> >> >Jim McGinn wrote:
>> >
>> >> >> Norman K. McPhail wrote in message
<356DD0...@socal.wanet.com>...
>> >> >> >Jim McGinn wrote:
>> >
>> >> >> >> Norman K. McPhail wrote in message
>> <356C9B...@socal.wanet.com>...
>> >> >> >> >Paul Crowley wrote:
>> >
>> >> >> >> >> On Tue, 26 May 1998 16:52:51 -0700, "Jim McGinn"
>> >> >> >> >> <jimm...@msn.com> wrote:
>> >
>> >> >> >> >> >>Paul Crowley heeft geschreven in bericht
>> >
>
>> >[I've snipped out most of the points we agree on so we can concentrate
on
>what I think are the unresolved issues.]
>> >>
>
>
>I wrote:
>
>> >We might agree on these things. But I doubt that you would agree with
>> >me when I claim that there are no laws of nature. Still, when I get
>> >through explaining why I think what we call "the laws of nature" are
>> >caused by our blind spot, we might agree to some extent.
>> >
>> >
>Jim responded:
>
>> My understanding of laws of nature is that they are unchangeable and
>> immutable over time and space. Maybe you might consider looking for a
>> better word than laws.
>
>The term laws is part of the problem. For me, it implies a set of rules
that
>are imposed in some way by forces greater than we can fathom.
>It is our cause and effect or problem and solution thought processes that
>makes nature appear to have a set of laws or rules governing things. These
>same thought processes help cause a blind spot that hides a good part of
the
>way things are from our understanding. The worst thing about this blind
spot
>is that it keeps us from understanding how blind we are.
>
>My view is that to understand these hidden realms, we ought to start with
the
>notion of differences. I have no clue as to why differences appear. But
once
>they occur, self organizing processes can also start.
>
>I think the ways the universe has evolved is just the self organizing data,
>matter and energy differences we see taking place through the differences
we
>call space/time. The rules we call the 'laws of nature' are just the ways
>all these differences have evolved so far. I think these rules may be as
>changeable as the differences and the self organizing processes themselves.
>(Does this make any sense?)
>
In a way yes, it does make sense. My only concern is that it doesn't embody
the kind of scientific conciseness that I think is appropriate for a
scientific discipline as I am assuming is expected in this newsgroup.
>I wrote:
>
>> >> >Yet we've seen that even though our forebears were adaptable, they
were
>> >> >not what we might call fit.
>> >>
>> >> If they weren't fit we wouldn't be here.
>
>> >Again, I'm making an arbitrary division between physical and mental
>> >fitness. You seem to be saying they are the same thing. I just say
>> >they are both the same and differ. Is there a good reason why they
>> >can't be the same and different?
>
>Jim responded:
>
>> I think its the word fit that's causing the problem. It has a relatively
>> specific connotation within any biological based discipline (one that
brings
>> many philosophers to refer to it as a tautology). How about if you use
the
>> word abilities instead of fitness.
>
>
>Abilities works. Would traits also work here?
>
>I wrote:
>
>> >I have no idea what the current paradigm of evolutionary theory is. Yet
>> >my guess is that there would not be many who would agree with my theory.
>> >So it's hard for me to imagine that my notions reflect the current
>> >paradigm.
>
>Jim responded:
>
>> What I mean by this is that it is typical to the subject matter of human
>> evolutionary theory to see theorists proposing solutions that use what we
>> might refer to as reverse adaptationists thinking. It goes something
like
>> this: humans are intelligent, therefore it we can imagine the
environmental
>> situations that would require them pick up tool and apply their
intelligence
>> then we can figure out the cause of human evolution. We see this kind of
>> thinking over and over again in this newsgroup. It's like a broken
record.
>
>We agree that this is a trap that most of us have fallen into at one time
or
>another. I've tried very hard to avoid the trap in describing how I think
>human understanding came to be. On the other hand, once it starts to rear
>it's funny head, it can be a self referencing component of a self
organizing
>process.
>
I don't think you really have a good grasp on what I am saying here. It's
very hard to explain this to somebody who doesn't have a background in
paleontology and/or evolutionary theory.
>Jim wrote:
>
>> This kind of thinking works very well for niche specific species but it
has
>> not, and never will, prove effective for humans. Most theorists are
simply
>> unable to come to grips with the fact that humans have broken out of the
>> constraints of being a niche specific species.
>
>I think we agree on this point. I use the word generalist, but I'm trying
to
>make the same point. I think your way of describing this is the best I've
>seen so far.
>
>Jim wrote:
>
>> They quite literally don't
>> know how to deal with it. Accordingly your statements above seem to >
>reflect
>> this popular notion.
>
>I may not have said it clearly enough. Someone of your background would
>probably quickly jump to that conclusion. But let me assure you, I have
come
>to my own conclusion that this switch to becoming a generalist was one of
the
>main steps that led to the great encephalization of our forebears.
I am not a proponent of any of the switch-to-become-a-generalist
hypotheses--of which there are many, among them being Indirect
Specialization Hypothesis and Multiple Habitat hypothesis. In my mind they
all lack Parsimony.
>
>Jim Wrote:
>
>> I'm saying that safety and sustenance drive change for all species.
>> Not just humans. This kind of thinking tells us nothing about why
>> humans are so *truly* unique.
>
>I wrote:
>
>> >Are you saying that changing food sources and threats don't select >
>for
>individuals who can find ways to meet these new tests? Or are > >you
saying
>that in the case of our forebears, there was a set of
>> >conditions and sequences that caused them to jump to a different mode >
>of
>adapting to these tests? One that is some ways was qualitatively >
>>different.
>
>Jim responded:
>
>> This is more accurate. Moreover I think (know) I've happened upon
exactly
>> what it is. (However, I'm not going to release this understanding until
>> I've had some more experience dealing with what I might offhandedly refer
to
>> as the "reverse adaptationist niche-specific assumptions that currently
>> dominate almost all thought in this discipline.") Human evolutionary
theory
>> is an extremely difficult field. It's the most intellectually seductive
>> field there is. Everybody from the time they are seven years old tends
to
>> think that they have the correct understanding of human origins. Its
very
>> human to think you know where we come from and why we are here.
>>
>> My approach is highly reductionist, mechanistic, deterministic, but
>> relativistic. The relativistic aspects of my approach are borne out of
the
>> application of reductionism, mechanism, and determinism, in that when
such
>> is applied to reality one realizes that relativism is the way reality
>> actually is. The highly absolutistic approach that is indemic in the
>> current paradigm is scientifically inferior due to the fact that is
>> absolutistic assumptions (which are built into our language and thought
>> processes) cause us to caricaturize many aspect of reality (especially
cause
>> and effect) rather than reflect it accurately. (I hope this makes
sense.)
>
>It is perfectly clear and makes sense to me. I have come to the same
>conclusions on my own.
>
>Jim Wrote:
>
>> >> And it is, essentially ready to be released. But I am not going to
>> release
>> >> it until I've had some experience wrestling with the paradigmatic
>> >> assumptions of the current paradigm.
>
>I responded:
>
>> >For what it's worth, I'd be happy to share my thoughts on this very real
>> >and illusive problem. It might even be something a good media expert
>> >might be able to help with.
>
>Jim responded:
>
>> This sounds like something I may very well be interested in.
>>
>Jim Wrote:
>
>> My focus with respect to where I hope to make a contribution to this
field
>> focuses on that point 4 to 5 million years ago when it all began.
>> Consequently the only field data that I am interested in involves
>> chimpanzees and the environmental change that took place back then. As
far
>> as I'm concerned until we figure out what happened at that point 4 to 5
>> million years ago to our chimpanzee-like ancestors the rest of human
>> evolution is bound to be speculative at best and highly misleading at
worst
>> (due to the fact that we are such a different animal now than we were
when
>> the process began). As I see it any theorist that is looking for the
cause
>> of human evolution is wasting their time if they look anywhere else. The
>> clues are all there. It's just a matter of putting them all together,
and
>> most importantly looking beyond the assumption of humans being a niche
>> specific species.
>
>> I haven't had a chance to look at DOHU yet so I don't know. You should
be
>> aware however, that whatever theory you come up with you have to account
for
>> why other species didn't achieve the same. In other words you have to
>> explain what it was specifically that caused chimpanzees to become human.
>> DOHU sounds too vague to achieve that end. But then again, I haven't
read
>> it yet.
>
>I wrote:
>
>> >So perhaps we can agree that there might be a way to tell the story of
>> >human evolution the way it is and still integrate it into our social,
>> >cultural, political and religious systems.
>
>Jim responded:
>
>> I don't know. It's that word integrate that bothers me.
>
>Well I concur that our cultural, civil, social and religious traditions and
>values are much more important than an accurate account of how and why we
got
>to be the way we are. Yet when the story is told within the language and
>context of these traditions and values, it sheds a whole new light on the
>wisdom and truth in these values and traditions. By the same token, most
of
>these secular and religious traditions and values reinforce the validity of
>the story.
>
They don't reinforce. They're mutually exclusive. It wasn't very long ago
that I thought as you do. But now I know differently.
>For me, all these pieces fit. This is one of the main reasons why I think
>this is the dawn of human understanding. And by the way, this broad
context
>may be a good way to frame your discovery.
>
>The main problem, as I see it, is that hardly anyone else seems to grasp
how
>exciting and interesting all this is. I doubt if anyone else is reading
this
>post or the others that preceded it. The lesson seems to be it is not the
>contents, but how you tell the story that sparks the interest and holds the
>attention of most people.
>
>-----== Posted via Deja News, The Leader in Internet Discussion ==-----
>http://www.dejanews.com/ Now offering spam-free web-based newsreading
Jim McGinn
Any scientific based understanding of human origins has got to explain why
humans have evolved such a resistance to scientific based understandings of
human origins.
Norman K. McPhail
> >[I've snipped out most of the points we agree on so we can concentrate
> on
> >what I think are the unresolved issues.]
> >Jim Wrote:
> I don't think you really have a good grasp on what I am saying here. It's
> very hard to explain this to somebody who doesn't have a background in
> paleontology and/or evolutionary theory.
You may well be correct in this. But keep in mind that you have not
told me the core elements of your idea. What's more, you have not taken
the time to read the DOHU. The point is simply that until we take the
time to exhchage thoughts and define our terms more precisely, we won't
be able to tell how close or distant our ideas are from one another.
Jim wrote:
> I am not a proponent of any of the switch-to-become-a-generalist
> hypotheses--of which there are many, among them being Indirect
> Specialization Hypothesis and Multiple Habitat hypothesis. In my mind they
> all lack Parsimony.
I expect your hypothesis is lean and mean and I expect that it's as good
as you say it is. If it is as good as I hope it is, it deserves to be
expressed in a way that the average person can understand it. I think
you owe it to the world to do whatever it takes to make it clearly
understood.
Isn't that what good scientists are supposed to do regardless of the
consequences? Or if, as you say, the consequences are so potentially
destructive maybe you should bury it forever and hope no one else ever
figures it out.
On the other hand, maybe someone else won't be so conscious of the
adverse consequences. So perhaps you ought to put the best spin
possible on it so the net effect does as little damage as possible.
I wrote:
> >Well I concur that our cultural, civil, social and religious traditions and
> >values are much more important than an accurate account of how and why we
> got
> >to be the way we are. Yet when the story is told within the language and
> >context of these traditions and values, it sheds a whole new light on the
> >wisdom and truth in these values and traditions. By the same token, most
> of
> >these secular and religious traditions and values reinforce the validity of
> >the story.
Jim responded:
> They don't reinforce. They're mutually exclusive. It wasn't very long ago
> that I thought as you do. But now I know differently.
> Any scientific based understanding of human origins has got to explain why
> humans have evolved such a resistance to scientific based understandings of
> human origins.
I think I understand why you say they are mutually exclusive, but
obviously I'm just guessing. I also agree that a "...scientific based
understanding our human origins" ought to help us learn why most of us
have such a hard time grasping such an understanding.
NK...@my-dejanews.com
Jim McGinn wrote:
>
> Norman K. McPhail wrote in message <357424...@socal.wanet.com>...
> >Norman K. McPhail wrote:
> >>
> >> >
> >> > Norman K. McPhail wrote in message <356F12...@socal.wanet.com>...
> >> > >Jim McGinn wrote:
> >>
> >> > >> Norman K. McPhail wrote in message <356DD0...@socal.wanet.com>...
> >> > >> >Jim McGinn wrote:
> >>
> >> > >> >> Norman K. McPhail wrote in message
> <356C9B...@socal.wanet.com>...
> >> > >> >> >Paul Crowley wrote:
> >>
> >> > >> >> >> On Tue, 26 May 1998 16:52:51 -0700, "Jim McGinn"
> >> > >> >> >> <jimm...@msn.com> wrote:
> >>
> >> > >> >> >> >>Paul Crowley heeft geschreven in bericht
> >> > >> >Norm wrote:
> >[snip]
> >> > >Most of us now grasp the fact that we humans have bent some of the > >
> >laws of nature.
> >
> >
-----== Posted via Deja News, The Leader in Internet Discussion ==-----
no...@socal.wanet.com
Jim McGinn wrote:
>
> Norman K. McPhail wrote in message <357360...@socal.wanet.com>...
> >Jim McGinn wrote:
> >>
> >> Norman K. McPhail wrote in message <356F12...@socal.wanet.com>...
> >> >Jim McGinn wrote:
> >
> >> >> Norman K. McPhail wrote in message <356DD0...@socal.wanet.com>...
> >> >> >Jim McGinn wrote:
> >
> >> >> >> Norman K. McPhail wrote in message
> <356C9B...@socal.wanet.com>...
> >> >> >> >Paul Crowley wrote:
> >
> >> >> >> >> On Tue, 26 May 1998 16:52:51 -0700, "Jim McGinn"
> >> >> >> >> <jimm...@msn.com> wrote:
> >
> >> >> >> >> >>Paul Crowley heeft geschreven in bericht
> >
> >[I've snipped out most of the points we agree on so we can concentrate on
what I think are the unresolved issues.]
> >>
I wrote:
> >We might agree on these things. But I doubt that you would agree with
> >me when I claim that there are no laws of nature. Still, when I get
> >through explaining why I think what we call "the laws of nature" are
> >caused by our blind spot, we might agree to some extent.
> >
> >
Jim responded:
> My understanding of laws of nature is that they are unchangeable and
> immutable over time and space. Maybe you might consider looking for a
> better word than laws.
The term laws is part of the problem. For me, it implies a set of rules that
are imposed in some way by forces greater than we can fathom.
It is our cause and effect or problem and solution thought processes that
makes nature appear to have a set of laws or rules governing things. These
same thought processes help cause a blind spot that hides a good part of the
way things are from our understanding. The worst thing about this blind spot
is that it keeps us from understanding how blind we are.
My view is that to understand these hidden realms, we ought to start with the
notion of differences. I have no clue as to why differences appear. But once
they occur, self organizing processes can also start.
I think the ways the universe has evolved is just the self organizing data,
matter and energy differences we see taking place through the differences we
call space/time. The rules we call the 'laws of nature' are just the ways
all these differences have evolved so far. I think these rules may be as
changeable as the differences and the self organizing processes themselves.
(Does this make any sense?)
I wrote:
> >> >Yet we've seen that even though our forebears were adaptable, they were
> >> >not what we might call fit.
> >>
> >> If they weren't fit we wouldn't be here.
> >Again, I'm making an arbitrary division between physical and mental
> >fitness. You seem to be saying they are the same thing. I just say
> >they are both the same and differ. Is there a good reason why they
> >can't be the same and different?
Jim responded:
> I think its the word fit that's causing the problem. It has a relatively
> specific connotation within any biological based discipline (one that brings
> many philosophers to refer to it as a tautology). How about it you use the
> word abilities instead of fitness.
Abilities works. Would traits also work here?
I wrote:
> >I have no idea what the current paradigm of evolutionary theory is. Yet
> >my guess is that there would not be many who would agree with my theory.
> >So it's hard for me to imagine that my notions reflect the current
> >paradigm.
Jim responded:
> What I mean by this is that it is typical to the subject matter of human
> evolutionary theory to see theorists proposing solutions that use what we
> might refer to as reverse adaptationists thinking. It goes something like
> this: humans are intelligent, therefore it we can imagine the environmental
> situations that would require them pick up tool and apply their intelligence
> then we can figure out the cause of human evolution. We see this kind of
> thinking over and over again in this newsgroup. It's like a broken record.
We agree that this is a trap that most of us have fallen into at one time or
another. I've tried very hard to avoid the trap in describing how I think
human understanding came to be. On the other hand, once it starts to rear
it's funny head, it can be a self referencing component of a self organizing
process.
Jim wrote:
> This kind of thinking works very well for niche specific species but it has
> not, and never will, prove effective for humans. Most theorists are simply
> unable to come to grips with the fact that humans have broken out of the
> constraints of being a niche specific species.
I think we agree on this point. I use the word generalist, but I'm trying to
make the same point. I think your way of describing this is the best I've
seen so far.
Jim wrote:
> They quite literally don't
> know how to deal with it. Accordingly your statements above seem to >
reflect
> this popular notion.
I may not have said it clearly enough. Someone of your background would
probably quickly jump to that conclusion. But let me assure you, I have come
to my own conclusion that this switch to becoming a generalist was one of the
main steps that led to the great encephalization of our forebears.
Jim Wrote:
> I'm saying that safety and sustenance drive change for all species.
> Not just humans. This kind of thinking tells us nothing about why
> humans are so *truly* unique.
I wrote:
> >Are you saying that changing food sources and threats don't select > >for
individuals who can find ways to meet these new tests? Or are > >you saying
that in the case of our forebears, there was a set of
> >conditions and sequences that caused them to jump to a different mode > >of
adapting to these tests? One that is some ways was qualitatively >
>different.
Jim responded:
> This is more accurate. Moreover I think (know) I've happened upon exactly
> what it is. (However, I'm not going to release this understanding until
> I've had some more experience dealing with what I might offhandedly refer to
> as the "reverse adaptationist niche-specific assumptions that currently
> dominate almost all thought in this discipline.") Human evolutionary theory
> is an extremely difficult field. It's the most intellectually seductive
> field there is. Everybody from the time they are seven years old tends to
> think that they have the correct understanding of human origins. Its very
> human to think you know where we come from and why we are here.
>
> My approach is highly reductionist, mechanistic, deterministic, but
> relativistic. The relativistic aspects of my approach are borne out of the
> application of reductionism, mechanism, and determinism, in that when such
> is applied to reality one realizes that relativism is the way reality
> actually is. The highly absolutistic approach that is indemic in the
> current paradigm is scientifically inferior due to the fact that is
> absolutistic assumptions (which are built into our language and thought
> processes) cause us to caricaturize many aspect of reality (especially cause
> and effect) rather than reflect it accurately. (I hope this makes sense.)
It is perfectly clear and makes sense to me. I have come to the same
conclusions on my own.
Jim Wrote:
> >> And it is, essentially ready to be released. But I am not going to
> release
> >> it until I've had some experience wrestling with the paradigmatic
> >> assumptions of the current paradigm.
I responded:
> >For what it's worth, I'd be happy to share my thoughts on this very real
> >and illusive problem. It might even be something a good media expert
> >might be able to help with.
Jim responded:
> This sounds like something I may very well be interested in.
>
Jim Wrote:
> My focus with respect to where I hope to make a contribution to this field
> focuses on that point 4 to 5 million years ago when it all began.
> Consequently the only field data that I am interested in involves
> chimpanzees and the environmental change that took place back then. As far
> as I'm concerned until we figure out what happened at that point 4 to 5
> million years ago to our chimpanzee-like ancestors the rest of human
> evolution is bound to be speculative at best and highly misleading at worst
> (due to the fact that we are such a different animal now than we were when
> the process began). As I see it any theorist that is looking for the cause
> of human evolution is wasting their time if they look anywhere else. The
> clues are all there. It's just a matter of putting them all together, and
> most importantly looking beyond the assumption of humans being a niche
> specific species.
> I haven't had a chance to look at DOHU yet so I don't know. You should be
> aware however, that whatever theory you come up with you have to account for
> why other species didn't achieve the same. In other words you have to
> explain what it was specifically that caused chimpanzees to become human.
> DOHU sounds too vague to achieve that end. But then again, I haven't read
> it yet.
I wrote:
> >So perhaps we can agree that there might be a way to tell the story of
> >human evolution the way it is and still integrate it into our social,
> >cultural, political and religious systems.
Jim responded:
> I don't know. It's that word integrate that bothers me.
Well I concur that our cultural, civil, social and religious traditions and
values are much more important than an accurate account of how and why we got
to be the way we are. Yet when the story is told within the language and
context of these traditions and values, it sheds a whole new light on the
wisdom and truth in these values and traditions. By the same token, most of
these secular and religious traditions and values reinforce the validity of
the story.
For me, all these pieces fit. This is one of the main reasons why I think
this is the dawn of human understanding. And by the way, this broad context
may be a good way to frame your discovery.
The main problem, as I see it, is that hardly anyone else seems to grasp how
exciting and interesting all this is. I doubt if anyone else is reading this
post or the others that preceded it. The lesson seems to be it is not the
contents, but how you tell the story that sparks the interest and holds the
attention of most people.
-----== Posted via Deja News, The Leader in Internet Discussion ==-----
Jim McGinn
Norman K. McPhail wrote in message <35763D...@socal.wanet.com>...
>> >[I've snipped out most of the points we agree on so we can concentrate
>> on
>> >what I think are the unresolved issues.]
>
>> >Jim Wrote:
>
>> I don't think you really have a good grasp on what I am saying here.
It's
>> very hard to explain this to somebody who doesn't have a background in
>> paleontology and/or evolutionary theory.
>
>You may well be correct in this. But keep in mind that you have not
>told me the core elements of your idea. What's more, you have not taken
>the time to read the DOHU. The point is simply that until we take the
>time to exhchage thoughts and define our terms more precisely, we won't
>be able to tell how close or distant our ideas are from one another.
>
>Jim wrote:
>
>> I am not a proponent of any of the switch-to-become-a-generalist
>> hypotheses--of which there are many, among them being Indirect
>> Specialization Hypothesis and Multiple Habitat hypothesis. In my mind
they
>> all lack Parsimony.
>
>I expect your hypothesis is lean and mean and I expect that it's as good
>as you say it is. If it is as good as I hope it is, it deserves to be
>expressed in a way that the average person can understand it. I think
>you owe it to the world to do whatever it takes to make it clearly
>understood.
>
>Isn't that what good scientists are supposed to do regardless of the
>consequences? Or if, as you say, the consequences are so potentially
>destructive maybe you should bury it forever and hope no one else ever
>figures it out.
>
>On the other hand, maybe someone else won't be so conscious of the
>adverse consequences. So perhaps you ought to put the best spin
>possible on it so the net effect does as little damage as possible.
you've hit the nail on the head here.
>
>I wrote:
>
>> >Well I concur that our cultural, civil, social and religious traditions
and
>> >values are much more important than an accurate account of how and why
we
>> got
>> >to be the way we are. Yet when the story is told within the language
and
>> >context of these traditions and values, it sheds a whole new light on
the
>> >wisdom and truth in these values and traditions. By the same token,
most
>> of
>> >these secular and religious traditions and values reinforce the validity
of
>> >the story.
>
>Jim responded:
>
>> They don't reinforce. They're mutually exclusive. It wasn't very long
ago
>> that I thought as you do. But now I know differently.
>
>> Any scientific based understanding of human origins has got to explain
why
>> humans have evolved such a resistance to scientific based understandings
of
>> human origins.
>
>I think I understand why you say they are mutually exclusive, but
>obviously I'm just guessing. I also agree that a "...scientific based
>understanding our human origins" ought to help us learn why most of us
>have such a hard time grasping such an understanding.
Its more than just, as you state, " . . . why most of us have such a hard
time grasping such an understanding." Rather its why we have evolved a
resistance to such an understanding as, literally, a survival mechanism.
The understanding of human evolution that I have discovered not only shows
us how and why humans evolved but it shows us that many of us--in the least
the greater majority of us--will be better off without this understanding.
Jim McGinn
Marc Verhaegen
Gerrit Hanenburg heeft geschreven in bericht
>>>- gorilla length in boisei ER-739, OH-36, L-40-19
This message in a previous form was not sent through, because too much "old"
text, so I have to "snip" some interesting things.
...
>>>Long arms are most parsimoniously interpreted as a primitive retention
>>>(symplesiomorphy).
Long arms, yes. Very long arms, no. The difference between rel.arm length in
orang & gorilla is larger than that between gorilla & human, see the work of
Schultz. Therefore the LCA of Pan-Homo-Gorilla had long arms, but probably
not very long (cf.orang, gibbon) arms.
An other argument is that extreme features usu. developed latest. IOW
because human rel.arm length is not much longer than cercopith rel.arm
length, the apes & certainly the Asiatic apes are derived in arm length. IMO
the very long arms of the apes are all derived (in parallel).
(For recent work on the importance of parallelism see JB Losos etc.
"..replicated adaptive radiations.." Sci.279:115, G.Vogel "For island
lizards, history repeats itself" Sci.279:2043, PH Harvey & L.Partridge
"Different routes to similar ends" Nat.392:552.
It is not enough realised by people that study evolution that parallelism,
convergence, fluctuating evolution is the essence of Darwinian adaptation
(but unfortunately it blurs evol.trees).
In the fossil record we see arm lengthening happening late (later than 2
mya):
- in the East Afircan robust line: the arm bones of gorilla length,
- in the East African gracile line: OH-62 had much longer arm bones than
Lucy.
>>If it was not boisei, it must have been Gorilla (IMO both) - what else?
>
>They're unlikely to be Gorilla
I didn't mean gorilla but belonging to the genus Gorilla rather than to Pan
or Homo.
If we have to choose between the 3 living African genera, the absolute size
indicates Gorilla.
The only other reasonable possibiltiy (the opinion of CE Oxnard) is that the
australopiths belonged to a fourth lineage that went completely extinct. The
molecular data suggest we have to split the australopiths into a large-sized
group belonging to Gorilla, and a smaller-sized group belonging to Homo-Pan.
The "problem" of many anthropologists is that there happens to be a large
amount of parallelism (which is only natural in evolution!) between the
lines leading to gorillas and that leading to (common) chimps.
White & Harris 1977 "Suid evolution.." Sci.198:13 saw exactly the same
problems in suid evolution, but their view was more readily accepted because
pigs are further away from us.
IOW, IMO, boisei belongs to the gorilla clade.
- Homo: very long legs, rel.short arms
- Pan: rel.short legs, rel.long arms
- Gorilla: very long arms, rel.short legs
The very long arm bones only fit Gorilla, but had not (yet?) evolved all
knuckle-walking features so long ago (2-1 mya).
K-W in gorillas & chimps probably evolved in parallel (IMO from more
bipedal ancestors). Gorilla K-W anatomy & ontogeny are different from & much
better developed (Inouyi 1992 AJPA suppl.14:55) & therefore probably older
than in chimps. IOW the K-W evolution leading to common chimp "followed"
that of gorilla (parallel, but perhaps somewhat later).
>(they lack the deep olecranon fossa
>with steep and sharp lateral margin and the proximoanterior
>orientation of the trochlear notch and heavily buttressed coronoid
>process characteristic of the knucklewalking apes).
Okay, but some K-W features were already developing 2-1 mya:
- great size (length & robusticity)
- L-40-19 curvature & cross-section cf. knuckle-walkers (Howell & Wood 1974
Nat.249:174)
- ER-739: "knuckle-walker condition not unlike the extant Afr.apes (Leakey
1971 Nat.231:241)
>They are probably P.boisei, but their taxonomic status is uncertain
>without associated diagnosable craniodental material, since isolated
>early hominin postcranial elements are difficult to diagnose (as
>McHenry (1994: 258) suggests, these large forelimbs may also belong to
>the species with the largest hindlimbs (e.g. KNM-ER 1481, possibly
>Homo rudolfensis).
Then you have to imagine an enormous creature with arms of gorilla length &
legs of human length, something like a giant spider monkey.
No: arms>legs in apes (& boisei & OH-62), legs>arms in Homo.
(IOW, OH-62 was some sort of chimp, too small for belonging to Gorilla)
Marc Verhaegen
Paul Crowley heeft geschreven in bericht
>"Dwight E. Howell"
>
>>> It would have been only marginally more common than in historical
>>> times -- only when desperate circumstances forced it. Otherwise
>>> the hominids would have known to avoid the liver.
>
>>If you eat your dog you may die of vitamin poisoning but it won't show
>>on fossil bones. That would only occur if you ate dog on a regular bases
>>for some time so that the condition could become chronic before you
>>died.
>
...
>Also if you got this reaction from eating dog liver on two or
>three occasions, and lived, you'd never eat it again. The only
>people who do so are in desperate circumstances and become too
>ill to know what they are doing.
Paul, do you mean ER-1808 died from acute hypervit.A?
(this is not what Walker etc. said)
I don't understand your preoccupation with dog eating:
- There is no serious evidence of vit.A intoxication. Even if the condition
in ER-1808 is pathological (not certain: it could have been adaptive),
Walker etc.1982 (A possible case of hypervit.A in H.erectus. Nat.296:248)
give a whole series of possible explanations: chronic (not acute?)
hypervit.A,
hypervit.D, hypoparathyroidism, fluorisis, hypovit.C (scurvy), generalised
cortical hyperostosis, osteomyelitis including syphilis & yaws.
- Even if chronic hypervit.A was the explanation (not impossible, but rather
improbable), why dog eating? Dogs are domesticated probably 'only' 100,000
ya. If they ate dogs to such an extent, the (wild) dogs would never stayed
around them & domestication would not have happened IMO.
- Even if hypervit.A was the explanation, eating the liver of seals, etc.
would have been more probable (& seems to be the most likely cause of
hypervit.A
today).
Marc
Marc Verhaegen
Paul Crowley >Marc Verhaegen"
This message was not posted (too much "old" material). So I cut a few
things.
>>No evidence of vit.A poisoning in hominid fossils! This solution was
>>"invented" because they could find any better.
>>(The thick bones can only be explained by slow diving.)
>This is quite wrong. See Alan Walker's "The Wisdom of Bones".
>The bones of KNM-ER 1808 and the Seveso hominid had a
>pathological layer which was quite unlike normal bone. When they
>were found they were not even identified as hominid bone.
(yaws osteomyelitis was proposed for the Seveso hominid)
Why assume that the ER-1808 tibia was pathological? Why not adaptive?
(Several neandertal features were once considered pathological)
Even if pathological, why hypervit.A? Walker etc.1982 Nat.296:248 give a lot
of other pathol.possibilities.
Even if hypervit.A, why by eating dog liver?? Why not bee brood as somebody
suggested!?
see M.Skinner 1991 JHE 20:493.
Eating vit.A pills or eating fish or whale or seal liver are the most common
causes of hypervit.A today.
Has anybody compared H.erectus' periostal bone deposition (esp. histology or
RX) with that in the vertebra of Lucy & Sts-14?
>>> you need to explain why all primates, other than us,
>>>possess them, considering they have an enormous range of diets.
>>
>>Gigantopith. had small canines. Some Sivapith. "ramapiths" had small
>>canines. Hapalemur (bamboo lemur) has small canines (not much longer than
>>its incisors & much shorter than Lemur). Some believe Gigantopith. ate a
lot
>>of bamboo.
>
>There may be some slight exceptions to the rule (all primates
>have large canines). You still need to explain it.
Slight exceptions??
Primate canines range from very short to very long, about 1x to 5x incisor
size. Primates are generally frugi/omnivores. Why should they not have
longer canines?
I just "explained", it's very simple, smaller canines (not only in primates)
usu. means an evolution towards herbivory, eg,
- robusts < early australopiths
- "Ramapith" < most Sivapith.
- Gigantopith < orangs
- Hapalemur < Lemur
- panda < bear
But canine reduction is also seen in most pinnipeds vs terrestrial
carnivores, & in most odontocete cetaceans - cf. eating fish or squid?
>
>>>Imagine us re-growing large canines! We would _first_ have to change our
>>method of mastication. Why on earth would we?
>>
>>The australopiths (very clear in africanus) still had buttressed maxillae
>>for the canines.
>
>So do we -- after four or so million years with canines the same
>size as incisors,
No, not 4 my.
H.erectus Sangiran <2mya still have projecting canines (p.36 in B.Rensch
1972 Homo sapiens. Columbia UP)
> our canine roots are still much deeper. Go to a mirror and have a look at
your gums.
Indeed, if we or australopiths needed longer canines (eg, more fruit-eating
but no knives) we could easily regrow longer canines, since our canine roots
are still deeper.
>>>As you well know, changes in dentition are extraordinarily slow
>>>in all taxa. They are distinctive to orders, families and
>>>genera. Your disregard of the permanence of their nature is
>>>cavalier.
As you well know, substantial changes in dentition are seen in australopiths
<1my.
And even within H.sapiens (<200,000), eg, more incisive prognathism in
Africans, more shovellike incisors in Asians.
>>("cavalier"? horse-rider?)
>
>Cavalier as in supporters of Charles I of England: "showing a
>haughty disregard". You need a good English dictionary. Thank
>God Dutch is not the language of the internet.
>
>Paul.
Paul Crowley
>If I were a leopard I would think twice before attacking a male boisei.
How could a male boisei be more dangerous to a leopard at_night_
than a male gorilla? The gorilla's bite is much more fearful. I
believe that the only way any hominids could have coped with the
danger of such nocturnal predation was by driving the predators
from their territory by means of regular patrolling by day --
probably with associated canines (dogs). Of course, this would
ony have been possible in certain areas or even locations.
>(You're comparing a leopard that can't afford to be hurt & a gorilla or
>boisei that will fight for its life.)
Leopards do prey on gorillas; possibly only on juveniles or on
sick adults.
>> The features relate to a niche that the
>>animal discovered. When you look at other species, you always
>>explain their existence from their features taken as a whole.
>
>Of course, but you can understand all their features apart!
>(Evolution works in parallel on all those different features. The
>individuals with the best combinations with survive.)
This is not true. The niche determines the combination that
works. It then maintains it by eliminating any features that
stray too far.
>>bipedalism does not go with clinging infants
>
>?? kangaroos
Primates don't have a pouch.
>(& wading gorillas in Congo Brazzaville forests)
I'd want to see this properly. How do female gorillas with young
infants manage to wade in water more than about 3 feet deep?
>> bipedalism requires altricial infants
>
>??
It's a theory I've put forward here many times. A female ape
with a 2 or 3-year old infant cannot travel upright. She has to
put the infant down. So the infant must be altricial.
>> manipulative hands require bipedalism;
>
>racoons
We're talking about large primates that will put serious weight
on their front limbs when quadrupedal.
>> the absence of canines requires manipulative hands;
>
>most herbivores
We're talking about primates.
>>the use of clubs requires bipedalism;
>
>chimps
The regular or continual use of clubs requires bipedalism.
>> sweating requies good supplies of water and salt;
>
>(water yes, it gives the cooling, but salt?)
Sweat is isotonic; its salt content reflects that of the blood.
So an animal that sweats heavily will continually lose salt. It
has to be able to replace it readily. So a species that develops
heavy sweating must live by the sea, and consume a diet
containing salt.
>>the absence of canines requires the use of clubs;
>
>horse?? capibara?? etc.
We are talking about large primates that can't readily flee or
hide from big cats.
> bipedalism requires the use of clubs; and so on.
>
>kangaroo
We are talking about large primates that can't escape predators
by running.
>>They are all inter-linked....
>
>They are "inter-linked" because they exist in humans! Post hoc ergo propter
>hoc.
We are trying to explain human evolution. But you can take any
species and study its characteristics. Some of these will be
unique, but all of them will be intimately inter-linked.
Paul.
Marc Verhaegen
Paul Crowley >Marc Verhaegen"
>>No evidence of vit.A poisoning in hominid fossils! This solution was
>>"invented" because they could find any better.
>>(The thick bones can only be explained by slow diving.)
>This is quite wrong. See Alan Walker's "The Wisdom of Bones".
>The bones of KNM-ER 1808 and the Seveso hominid had a
>pathological layer which was quite unlike normal bone. When they
>were found they were not even identified as hominid bone.
Why assume that the ER-1808 tibia was pathological? Why not adaptive?
(Several neandertal features were once considered pathological)
Even if pathological, why hypervit.A? Walker etc.1982 Nat.296:248 give a lot
of other pathol.possibilities.
Even if hypervit.A, why by eating dog liver??
Has anybody compared H.erectus' periostal bone deposition (esp. histology or
RX) with that in vertebra of Lucy & Sts-14?
...
>>Gigantopith. had small canines. Some Sivapith. "ramapiths" had small
>>canines. Hapalemur (bamboo lemur) has small canines (not much longer than
>>its incisors & much shorter than Lemur). Some believe Gigantopith. ate a
lot
>>of bamboo.
>
>There may be some slight exceptions to the rule (all primates
>have large canines). You still need to explain it.
Slight exceptions??
Primate canines range from very short to very long, about 1x to 5x incisor
size. (Primates are generally frugi/omnivores. Why should they not have
longer canines?)
I just "explained": smaller canines (not only in primates) = evolution
toward herbivory (eg, Australopith, Gigantopith, Hapalemur < Lemur, panda <
bear)
>
>
>>>Imagine us re-growing large canines! We would _first_ have to change our
>>method of mastication. Why on earth would we?
>>
>>The australopiths (very clear in africanus) still had buttressed maxillae
>>for the canines.
>
>So do we -- after four or so million years with canines the same
>size as incisors, our canine roots are still much deeper. Go to
>a mirror and have a look at your gums.
Indeed, if we or australopiths needed longer canines (eg, more fruit-eating
but no knives) there is no reason to not regrow longer canines.
>
>>>As you well know, changes in dentition are extraordinarily slow
>>>in all taxa. They are distinctive to orders, families and
>>>genera. Your disregard of the permanence of their nature is
>>>cavalier.
Substantial changes in dentition are seen in australopiths <1my.
And even within H.sapiens (<200,000).
Marc
Marc Verhaegen
Paul Crowley heeft geschreven in bericht
>On Wed, 3 Jun 1998 23:56:46 +0200, "Marc Verhaegen"
><Marc.Ve...@village.uunet.be> wrote:
...
>believe that the only way any hominids could have coped with the
>danger of such nocturnal predation was by driving the predators
>from their territory by means of regular patrolling by day --
>probably with associated canines (dogs). Of course, this would
>ony have been possible in certain areas or even locations.
Australopiths with dogs??? Please Paul. Why not sheep with dogs?
...
>>> The features relate to a niche that the
>>>animal discovered. When you look at other species, you always
>>>explain their existence from their features taken as a whole.
>>
>>Of course, but you can understand all their features apart!
>>(Evolution works in parallel on all those different features. The
>>individuals with the best combinations with survive.)
>
>This is not true. The niche determines the combination that
>works. It then maintains it by eliminating any features that
>stray too far.
I think you must read RJ Silson 1988 (Additive genes in evolution and
selection. Greenfield Publ., Tring). Yes, selection works so well and so
fast because the individuals with the best combinations are preserved (the
more "good" features you have in a certain milieu, the better your surviving
chances), but the features themselves are inherited apart. You say those
features are only suited in combination, that's nonsense: they all have to
be good on their own (in the given environment), otherwise their chances of
being selected are negligible.
...
>>(& wading gorillas in Congo Brazzaville forests)
>
>I'd want to see this properly. How do female gorillas with young
>infants manage to wade in water more than about 3 feet deep?
They swim (in swamps, full of the herbs the gorillas eat) and cling to their
mothers. You should see the film, beautiful. These swamps are/were quite
common in the tropics, and are the milieu where forest elephants or Asicatic
rhinos or hippos or capibaras live.
...
>>> manipulative hands require bipedalism;
>>
>>racoons
>
>We're talking about large primates that will put serious weight
>on their front limbs when quadrupedal.
Even chimps with their knuckle-walking hands can pick up needles.
...
>>> sweating requies good supplies of water and salt;
>>
>>(water yes, it gives the cooling, but salt?)
>
>Sweat is isotonic; its salt content reflects that of the blood.
No, there is active excretion of natrium.
...
>>>They are all inter-linked....
>>
>>They are "inter-linked" because they exist in humans! Post hoc ergo
propter hoc.
>
>We are trying to explain human evolution. But you can take any
>species and study its characteristics. Some of these will be
>unique, but all of them will be intimately inter-linked.
Primates are mammals just as any other. When you keep believing that humans
or even primates are different from other mammals, you'll never be able to
explain our evolution.
We are no exception. It's only the combination of our features that makes us
unique, not the features themselves. But then all species are unique, though
some combinations (eg, human, elephant) are of course much more unique than
others. Paul, you must start thinking more analytically.
You make things unnecessarily complicated. It's simple: you must not explain
short canines plus using clubs, you must explain a) short canines, b) using
clubs. Etc.
(Most anthropologists are even worse than you.)
For instance, short canines are seen in many herbivores. Using sticks or
clubs is seen in capuchins, chimps etc. Bipedalism is seen in all wading
primates. Etc.
Marc
Dwight E. Howell
> Sweat is isotonic; its salt content reflects that of the blood.
> has to be able to replace it readily. So a species that develops
> heavy sweating must live by the sea, and consume a diet
> containing salt.
The above statement may reflect the authors opinion but is obviously way
wrong.
The natives in the heart of the Australian out back sweated profusely
but did not live near the sea. The native in the New Guinea Highlands
have only recently obtained such a source of salt such salt.
The news from Brazil is of the discovery of a new tribe near the
mountains and in the lowlands but never contacted by Europeans who had
no source of sea salt.
Even the farmers of western China suffered and sometimes still suffer
from iodine deficiency because they don't use sea salt. The condition
was common in most inland regions though not all.
The answer is staring you in the face Paul. How do all the people get
along without sea salt?
I'm counting on you to use your brain this time around Paul. Don't let
me down. How do all these people not to mention nearly all the wild
herbivores get along without sea salt?
If you can't figure this out on your own look up salt in any cheap or
other wise encyclopedia. Heck, a good dictionary might do.
Dwight E. Howell
Marc Verhaegen wrote:
> Paul Crowley >Marc Verhaegen"
>
> This message was not posted (too much "old" material). So I cut a few
> things.
>
> >>No evidence of vit.A poisoning in hominid fossils! This solution was
>
> >>"invented" because they could find any better.
> >>(The thick bones can only be explained by slow diving.)
>
> >This is quite wrong. See Alan Walker's "The Wisdom of Bones".
> >The bones of KNM-ER 1808 and the Seveso hominid had a
> >pathological layer which was quite unlike normal bone. When they
> >were found they were not even identified as hominid bone.
>
> (yaws osteomyelitis was proposed for the Seveso hominid)
>
> Why assume that the ER-1808 tibia was pathological? Why not adaptive?
> (Several neandertal features were once considered pathological)
> Even if pathological, why hypervit.A? Walker etc.1982 Nat.296:248 give
> a lot
> of other pathol.possibilities.
> Even if hypervit.A, why by eating dog liver?? Why not bee brood as
> somebody
> suggested!?
> see M.Skinner 1991 JHE 20:493.
> Eating vit.A pills or eating fish or whale or seal liver are the most
> common
> causes of hypervit.A today.
>
> Has anybody compared H.erectus' periostal bone deposition (esp.
> histology or
> RX) with that in the vertebra of Lucy & Sts-14?
>
> >>> you need to explain why all primates, other than us,
> >>>possess them, considering they have an enormous range of diets.
> >>
> >>Gigantopith. had small canines. Some Sivapith. "ramapiths" had small
>
> >>canines. Hapalemur (bamboo lemur) has small canines (not much longer
> than
> >>its incisors & much shorter than Lemur). Some believe Gigantopith.
> ate a
> lot
> >>of bamboo.
> >
> >There may be some slight exceptions to the rule (all primates
> >have large canines). You still need to explain it.
>
> Slight exceptions??
> Primate canines range from very short to very long, about 1x to 5x
> incisor
> size. Primates are generally frugi/omnivores. Why should they not have
>
> longer canines?
> I just "explained", it's very simple, smaller canines (not only in
> primates)
> usu. means an evolution towards herbivory, eg,
> - robusts < early australopiths
> - "Ramapith" < most Sivapith.
> - Gigantopith < orangs
> - Hapalemur < Lemur
> - panda < bear
> But canine reduction is also seen in most pinnipeds vs terrestrial
> carnivores, & in most odontocete cetaceans - cf. eating fish or squid?
>
> >
> >>>Imagine us re-growing large canines! We would _first_ have to
> change our
> >>method of mastication. Why on earth would we?
> >>
> >>The australopiths (very clear in africanus) still had buttressed
> maxillae
> >>for the canines.
> >
> >So do we -- after four or so million years with canines the same
> >size as incisors,
>
> No, not 4 my.
> H.erectus Sangiran <2mya still have projecting canines (p.36 in
> B.Rensch
> 1972 Homo sapiens. Columbia UP)
>
> > our canine roots are still much deeper. Go to a mirror and have a
> look at
> your gums.
>
> Indeed, if we or australopiths needed longer canines (eg, more
> fruit-eating
> but no knives) we could easily regrow longer canines, since our canine
> roots
> are still deeper.
>
> >>>As you well know, changes in dentition are extraordinarily slow
> >>>in all taxa. They are distinctive to orders, families and
> >>>genera. Your disregard of the permanence of their nature is
> >>>cavalier.
>
> As you well know, substantial changes in dentition are seen in
> australopiths
> <1my.
> And even within H.sapiens (<200,000), eg, more incisive prognathism in
>
> Africans, more shovellike incisors in Asians.
>
> >>("cavalier"? horse-rider?)
> >
> >Cavalier as in supporters of Charles I of England: "showing a
> >haughty disregard". You need a good English dictionary. Thank
> >God Dutch is not the language of the internet.
> >
> >Paul.
By the way have any of you gentlemen noted that YOU can't close your
mouth so that your jaw teeth touch and slide your jaws from side to side
as early HS or the apes in question could. Turns out a big chunk of the
modern human race has an overbit that locks our jaws just as well as big
canines ever could only both sexes have this defect or whatever it is.
Paul Crowley
>Paul, do you mean ER-1808 died from acute hypervit.A?
>(this is not what Walker etc. said)
It's what he says in his "The Wisdom of Bones".
>I don't understand your preoccupation with dog eating:
It appears to be the main way modern victims acquired the
condition; I see no great reason to believe that earlier
hominids behaved differently -- i.e. they went to desert
locations, starved and ate their animals.
>Even if hypervit.A, why by eating dog liver??
There was a group of hominids because KNM_ER 1808 would have
taken some weeks, or months, to die and would have needed care
and protection during that time. That group clearly knew nothing
about the dangers of carnivore liver; so they were eating
something unusual. It's not likely that they captured a series
of wild cats, canids or hyenas. If they were capable of that,
they'd have hunted them normally and known the danger. They were
clearly in desperate situation. So what are we left with?
My "early association with dogs" hypothesis has been argued at
length here. Apart from KNM-ER 1808 there's no good evidence
either way. But I have seen no other account that seriously
tries to explain the ability of hominids to survive devastating
predation (especially nocturnal predation) prior (or even after)
the acquisiton of fire.
Hopefully it will soon be possible to date, from DNA studies, the
relative atrophication of the human sense of smell. It could
only come from the relationship with canids.
>- There is no serious evidence of vit.A intoxication. Even if the condition
>in ER-1808 is pathological (not certain: it could have been adaptive),
>Walker etc.1982 (A possible case of hypervit.A in H.erectus. Nat.296:248)
>give a whole series of possible explanations: chronic (not acute?)
>hypervit.A,
>hypervit.D, hypoparathyroidism, fluorisis, hypovit.C (scurvy), generalised
>cortical hyperostosis,
None of these seem to present similar effects on the long bones.
>osteomyelitis including syphilis & yaws.
Diseases like these usually need large and dense populations.
>- Even if chronic hypervit.A was the explanation (not impossible, but rather
>improbable), why dog eating? Dogs are domesticated probably 'only' 100,000
>ya.
What conditions arose at 100 kya that made domestication
desirable and possible, which weren't there before? Or did it
become a new and fashionable hobby, a bit like skateboarding?
>If they ate dogs to such an extent, the (wild) dogs would never stayed
>around them & domestication would not have happened IMO.
People who eat dogs regularly know about the liver problem. Dog
liver is only eaten by people in desperate circumstances who have
never had occasion to try it before.
>- Even if hypervit.A was the explanation, eating the liver of seals, etc.
>would have been more probable (& seems to be the most likely cause of
>hypervit.A today).
Those who hunt seals (like the Inuit) or eat carnivorous fish
(like us) do so regularly and learn to avoid the liver. And East
Rudolf is a long way from the sea.
Paul.
Paul Crowley
>> Sweat is isotonic; its salt content reflects that of the blood.
>> So an animal that sweats heavily will continually lose salt. It
>> has to be able to replace it readily. So a species that develops
>> heavy sweating must live by the sea, and consume a diet
>> containing salt.
>The natives in the heart of the Australian out back sweated profusely
>but did not live near the sea. The native in the New Guinea Highlands
>have only recently obtained such a source of salt such salt.
I presume that you accept that salt is essential in the human
diet. If so, we are only talking of its source -- whether it has
to be the sea or can be obtained inland.
>The news from Brazil is of the discovery of a new tribe near the
>mountains and in the lowlands but never contacted by Europeans who had
>no source of sea salt.
Many modern people live in places where it's hard to get salt.
They have to live near it, or frequently travel distances to it,
or pay for it in one way or another. The question is: "Would
such an animal have evolved in such a location?" or "Would a
species without ready access to salt have evolved a mechanism
that required large quantities?"
I suggest that the answers are clearly "no". There are plenty of
other cooling mechanisms that are not wasteful of salt. Panting,
throat pouches, large floppy ears, high crests, and so on. An
animal that evolves a system that dumps out so much salt must
normally have had an abundance of it in its diet.
We must also have evolved in a habitat with warm nocturnal
temperatures, since we have no insulation against cold. Such fat
as we may have is in the wrong places. This is especially
noticeable in our children and infants. All such habitats are
close to the sea.
> How do all these people not to mention nearly all the wild
>herbivores get along without sea salt?
All mammals need salt. But only humans regularly sweat it out in
quantity. Others that occasionally sweat, such as horses, have
to be migratory; they search out salt deposits on their travels.
Paul.
Paul Crowley
>Even chimps with their knuckle-walking hands can pick up needles.
Are you sure? Their "fine grip" is between their thumb and the
side of their forefinger. I can't pick up needle like that. Can
you? They'd use their lips for such delicate tasks.
>>Sweat is isotonic; its salt content reflects that of the blood.
>
>No, there is active excretion of natrium.
What evidence do you have for this?
>Primates are mammals just as any other. When you keep believing
>that humans or even primates are different from other mammals,
>you'll never be able to explain our evolution.
If I've done this, please point out how.
>We are no exception. It's only the combination of our features
>that makes us unique, not the features themselves. But then all
>species are unique, though some combinations (eg, human,
>elephant) are of course much more unique than others. Paul, you
>must start thinking more analytically.
You need to think more sythetically.
>You make things unnecessarily complicated. It's simple: you must
>not explain short canines plus using clubs, you must explain
>a) short canines, b) using clubs. Etc.
If a taxa appears to undergo two major changes simultaneously and
a possible link can be seen, then it is much more parsimonious to
propose one reason rather than two.
>For instance, short canines are seen in many herbivores.
Herbivores have short canines mainly in order to eat grass. It's
not sensible to propose a grass-eating primate, or even in the
hominid (normal definition) line, a leaf-eating one. A taxa
rarely develops new digestive systems; and if one did, there
should be living relatives.
>Using sticks or clubs is seen in capuchins, chimps etc.
Chimps, etc., don't use clubs regularly, so there's no pressure
for them to develop bipedalism or drop the use of canines.
>Bipedalism is seen in all wading primates. Etc.
Wading primates don't show enough bipedalism to be able to use
clubs or be forced to put infants down.
Generally you don't appreciate the difficulty of finding a new
niche. On continents a finch cannot adapt to a tit diet because
the tits are already there. A primate is not going to start
eating vegetation in an open area because there are already
plenty of highly specialist bovids and antelopes.
If you are going to propose such a jump you need to say how and
why such a niche came into existence -- why there were no bovids
already eating that vegetation, or if there were, what advantages
the primate had over them. You also need to say why no modern
primate occupies that niche, or a closely related one.
Paul.
Dwight E. Howell
Paul Crowley wrote:
Most likely but that doesn't' mean that somebody might not eat some
especially if food was short or maybe dine on fox, weasel, etc.
> Dog
> liver is only eaten by people in desperate circumstances who have
> never had occasion to try it before.
>
How would you even start to prove this?
> >- Even if hypervit.A was the explanation, eating the liver of seals,
> etc.
> >would have been more probable (& seems to be the most likely cause of
>
> >hypervit.A today).
>
> Those who hunt seals (like the Inuit) or eat carnivorous fish
> (like us) do so regularly and learn to avoid the liver. And East
> Rudolf is a long way from the sea.
>
But in a land rich in meat eaters of all shapes and sizes.
> Paul.
The real problem here is that for the condition to become chronic and
show in the bones is that he would have had to eat parts of perhaps a
dozen or so animals over a period of weeks. The group was most unlikely
to have that many dogs. What was most likely happening at this stage was
that pups would be taken from wild flesh eaters and keep for a while as
pets and maybe hunting companions. If food ran short they became lunch.
You might over a time span of years develop such a condition but it is
still sort of far fetched. The time frame between canine meals is just
to long.
Of course if somebody developed a taste for the livers of flesh eaters
anything is possible.
Dwight E. Howell
Paul Crowley wrote:
> On Tue, 09 Jun 1998 21:27:04 -0500, "Dwight E. Howell"
> <deo...@usit.net> wrote:
>
> >> Sweat is isotonic; its salt content reflects that of the blood.
> >> So an animal that sweats heavily will continually lose salt. It
> >> has to be able to replace it readily. So a species that develops
> >> heavy sweating must live by the sea, and consume a diet
> >> containing salt.
>
> >The natives in the heart of the Australian out back sweated profusely
>
> >but did not live near the sea. The native in the New Guinea Highlands
>
> >have only recently obtained such a source of salt such salt.
>
> I presume that you accept that salt is essential in the human
> diet. If so, we are only talking of its source -- whether it has
> to be the sea or can be obtained inland.
>
> >The news from Brazil is of the discovery of a new tribe near the
> >mountains and in the lowlands but never contacted by Europeans who
> had
> >no source of sea salt.
>
> Many modern people live in places where it's hard to get salt.
> They have to live near it, or frequently travel distances to it,
> or pay for it in one way or another. The question is: "Would
> such an animal have evolved in such a location?" or "Would a
> species without ready access to salt have evolved a mechanism
> that required large quantities?"
>
The answer is yes if the salt is there to be gotten. We also don't have
the ability to drink salty water or get rid of excess salt. Something
needed in animals that live in salt water and useful in deserts. Profuse
sweating would be a big problem for a salt water creature unless it can
drink salt water or had a good source of fresh water always available.
It would still be a bad idea unless the pay off was big.
> I suggest that the answers are clearly "no". There are plenty of
> other cooling mechanisms that are not wasteful of salt. Panting,
> throat pouches, large floppy ears, high crests, and so on. An
> animal that evolves a system that dumps out so much salt must
> normally have had an abundance of it in its diet.
>
> We must also have evolved in a habitat with warm nocturnal
> temperatures, since we have no insulation against cold. Such fat
> as we may have is in the wrong places. This is especially
> noticeable in our children and infants. All such habitats are
> close to the sea.
>
Please work on the above. It does not seem to have a main idea or even
belong together.
> > How do all these people not to mention nearly all the wild
> >herbivores get along without sea salt?
>
> All mammals need salt. But only humans regularly sweat it out in
> quantity. Others that occasionally sweat, such as horses, have
> to be migratory; they search out salt deposits on their travels.
>
The wild horse of the American west is not migratory but it still gets
salt at the local salt lick. The fact is that at least small amounts of
not very pure salt are widely distributed and are commonly exploited by
animals as well as people. It is there if you want it in most cases. It
thus does not constitute a barrier except in your head.
>
By the way most tropic people living on an unimproved diet are notable
for a lack of fat. Being fat is sort of a luxury.
> Paul.
Dwight E. Howell
Paul Crowley wrote:
> On Tue, 9 Jun 1998 22:23:14 +0200, "Marc Verhaegen"
> <Marc.Ve...@village.uunet.be> wrote:
>
> >Even chimps with their knuckle-walking hands can pick up needles.
>
> Are you sure? Their "fine grip" is between their thumb and the
> side of their forefinger. I can't pick up needle like that. Can
> you? They'd use their lips for such delicate tasks.
>
> >>Sweat is isotonic; its salt content reflects that of the blood.
> >
What happened to all other hominids seems to very plain and straight
forward. We eliminated them. Even Gigantopithocus (sp) which was more
related to Orangutans( sp). May be a few died from other environmental
reasons but I would not wager on it.
Marc Verhaegen
Paul Crowley heeft geschreven in bericht
<35810c83...@news.indigo.ie>...
>On Tue, 9 Jun 1998 22:23:14 +0200, "Marc Verhaegen"
><Marc.Ve...@village.uunet.be> wrote:
>
>>Even chimps with their knuckle-walking hands can pick up needles.
>
>Are you sure? Their "fine grip" is between their thumb and the
>side of their forefinger. I can't pick up needle like that. Can
>you? They'd use their lips for such delicate tasks.
I read it somewhere, I think, but am not sure.
(In fact, apes have narrower fingertips than humans, ie, more suited for
fine grasping than our broader fingertips, wouldn't you think?)
>>>Sweat is isotonic; its salt content reflects that of the blood.
>>
>>No, there is active excretion of natrium.
>
>What evidence do you have for this?
Sorry, I should have said: sweat is not isotonic. As in the kidneys, there
are active excretions and reabsorptions of ions (it's a long time ago that I
had to learn this).
See, eg, Schmidt-Nielsen 1979 Desert Animals (Dover NY): "values for sodium
& chloride for sweat vary a great deal, & range from about 5 to over 100
mEq/l"
...
>>You make things unnecessarily complicated. It's simple: you must
>>not explain short canines plus using clubs, you must explain
>>a) short canines, b) using clubs. Etc.
>
>If a taxa appears to undergo two major changes simultaneously and
>a possible link can be seen, then it is much more parsimonious to
>propose one reason rather than two.
Simultaneous?? Why do you think so?
Even then, the combination of 2 features is less parsimonious than the 2
features apart!
...
Paul, about canine reduction & herbivory, etc., please re-read & re-think
our previous discussions.
Marc
Marc Verhaegen
Paul Crowley >Marc Verhaegen
>>Paul, do you mean ER-1808 died from acute hypervit.A?
>>(this is not what Walker etc. said)
>
>It's what he says in his "The Wisdom of Bones".
but not what he says in Nature 296:248 (1982).
>>I don't understand your preoccupation with dog eating:
>
>It appears to be the main way modern victims acquired the condition;
I thought modern humans usu. get hypervit.A by eating fish or whale or seal
liver.
See E.Morgan 1982 The aquatic ape. Souvenir London p.122
> I see no great reason to believe that earlier
>hominids behaved differently -- i.e. they went to desert
>locations, starved and ate their animals.
"their" animals: DNA studies say domestication of modern dogs is "only"
100,000 years, as you know: the LCA of dogs & wolves lived ca.100,000 years
ago.
Or do you believe they ate their "wolves", re-domesticated wolves, ate them
again, re-domesticatted them again, etc.. etc.??
>>Even if hypervit.A, why by eating dog liver??
>
>There was a group of hominids because KNM-ER 1808 would have
>taken some weeks, or months, to die and would have needed care
>and protection during that time. That group clearly knew nothing
>about the dangers of carnivore liver; so they were eating
>something unusual. It's not likely that they captured a series
>of wild cats, canids or hyenas. If they were capable of that,
>they'd have hunted them normally and known the danger. They were
>clearly in desperate situation. So what are we left with?
Fish, seal, dugong, turtle, perhaps, but why dog???
(still in the supposition that the bone thickening was pathological and that
vit.A was the reason)
>My "early association with dogs" hypothesis has been argued at
>length here. Apart from KNM-ER 1808 there's no good evidence
>either way. But I have seen no other account that seriously
>tries to explain the ability of hominids to survive devastating
>predation (especially nocturnal predation) prior (or even after)
>the acquisiton of fire.
And devastating predation by dogs/wolves?? Why would you let you domesticate
by your prey??
>Hopefully it will soon be possible to date, from DNA studies, the
>relative atrophication of the human sense of smell. It could
>only come from the relationship with canids.
No, our poor olfaction is what is seen in aquatic mammals, eg, mysticetes
have rudimentary olfactory bulbs, odontocetes have even less.
The human olf.bulb is about one third that of chimps, and even chimps have
smaller olf.bulbs than baboons. Our wading ancestors (mangrove swamps?)
needed less olfaction than terrestrial relatives (baboons..), our diving
ancestors needed even less.
>>- There is no serious evidence of vit.A intoxication. Even if the
condition
>>in ER-1808 is pathological (not certain: it could have been adaptive),
>>Walker etc.1982 (A possible case of hypervit.A in H.erectus. Nat.296:248)
>>give a whole series of possible explanations: chronic (not acute?)
hypervit.A,
>>hypervit.D, hypoparathyroidism, fluorisis, hypovit.C (scurvy), generalised
>>cortical hyperostosis,
>
>None of these seem to present similar effects on the long bones.
???
(the list includes acute & chronic vit.A)
>>osteomyelitis including syphilis & yaws.
>
>Diseases like these usually need large and dense populations.
certainly not necessarily
>>- Even if chronic hypervit.A was the explanation (not impossible, but
rather
>>improbable), why dog eating? Dogs are domesticated probably 'only' 100,000
ya.
>
>What conditions arose at 100 kya that made domestication
>desirable and possible, which weren't there before?
...
That's not the point. There is the DNA evidence of dog domestication 100
kya.
(If you want some speculation:
The LCA of living humans lived ca.150-100 kya ("Afr.Eve"). Perhaps it's
exactly dog domestication that made us superior to earlier humans:
protection against other carnivores? against enemies? better hunting? large
game hunting?
IMO our final reterrestrialisation (full bipedalism with basicranial flexion
etc., no much diving any more, frequent hunting of large game) took place
only ca.150 kya in Africa. From there they rapidly spread over Eurasia &
wiped out other Homo species (neandertal, erectus).
Marc
Marc Verhaegen
Paul Crowley
>>My "early association with dogs" hypothesis has been argued at
>>length here. Apart from KNM-ER 1808 there's no good evidence either way.
Paul, if you only have ER-1808, you could perhaps argue that there was an
association between hypervit.A and Homo (erectus), but all this says
absolutely nothing about the australopithecines.
You must make the distinction. H.erectus is probably "close" to us (split
probably at least 1 mya, cf. Neandertals/humans~500,000 ya), australopiths
are much further related (probably more than 4 mya).
When I first read the Walker-Leakey 1982 Nat.296:248 paper on ER-1808, I
assumed that this bone thickening was not pathological (pathologies are
always exceptions & thus less probable than the healthy state), but just
another way of making erectus' bones heavier (selection always works in
parallel), like the narrower bone marrow. But of course, other explanations
are possible.
>>What conditions arose at 100 kya that made domestication
>>desirable and possible, which weren't there before?
>There is the DNA "evidence" of dog domestication 100 kya.
>If you want some speculation:
>The LCA of living humans lived ca.150-100 kya ("Afr.Eve"). Perhaps it's
>exactly dog domestication that made us superior to earlier humans:
>protection against other carnivores? against enemies? better hunting? large
>game hunting?
...
>Marc
But, yes, why dog domestication 100 or perhaps 150 kya??
- Cooperation in hunting, at first by accident? eg, humans (with fire? with
spears?) driving herds of prey toward wolf packs? Then the wolves killed the
prey animals at their side, the humans at the other side, and gradually they
came closer & respected each other. Fire is probably older than 150 kya,
spears/harpoons no doubt are older (400 kya German finds).
- An African Eve branch leaving Africa ca.100 kya? (wolves live in Eurasia).
But then, why did they only leave Africa 100 kya?
Marc
Jukka Korpela
>"their" animals: DNA studies say domestication of modern dogs is "only"
>100,000 years, as you know: the LCA of dogs & wolves lived ca.100,000 years
>ago.
Dogs are wolves. That is, dogs and wolves are quite capable of
cross-breeding (producing fertile offspring), and in modern scientific
presentations they are regarded as one species. Thus, the very concept
of last common ancestor of dogs and wolves makes no sense.
DNA studies cannot say when dogs were domesticated, although they
might give us _some_ data related to that. (There are certainly racial
differences within Canis lupus, and something might be deduced from
quantitative information related to that, but we would then need to
_assume_ how much interbreeding there has been between dogs and
wolves. Certainly more than nowadays, but how much more?)
I have never before seen such an estimate of 100,000 years. Usually
estimates are order of magnitude smaller. On the other hand, the whole
topic is fuzzy. Domestication, especially when speaking about dogs, is
a very vague concept. We don't even know how dogs were domesticated.
There might have been a very long hangaround period in the relation of
wolves to people, perhaps resembling the relationship between dingos
and abos.
--
Yucca, http://www.hut.fi/u/jkorpela/ or http://yucca.hut.fi/yucca.html
Paul Crowley
On Fri, 12 Jun 1998 21:44:42 -0500, "Dwight E. Howell"
<deo...@usit.net> wrote:
>Paul Crowley wrote:
>> People who eat dogs regularly know about the liver problem.
>
>Most likely but that doesn't' mean that somebody might not eat some
>especially if food was short or maybe dine on fox, weasel, etc.
We can take it that food was virtually always short. If hominids
had been eating animals with poisonous livers, they'd have taken
a few bites of liver from time to time, and in a few generations
the species would have adapted. (I have, in fact, heard that
Inuit have a higher tolerance to vitamin-A derived from their
diet of seals -- although they know to avoid the liver, and they
never touch polar-bear liver). So, we can be sure that they
weren't hunting foxes, weasels, or any carnivorous animals; and
we should doubt if they hunted much at all until quite recently.
>> Dog
>> liver is only eaten by people in desperate circumstances who have
>> never had occasion to try it before.
>
>How would you even start to prove this?
I'm lost as to the sense of your question. How does one prove
1+1=2? Individuals in societies (such as ours) that don't eat
dogs will only do so when a small band gets isolated in a desert.
And they do it because they're ignorant of the dangers. Societies
that do eat dogs will know the dangers. You probably eat
mackerel, but you don't eat mackerel liver -- although if you
found yourself on a desert island you might do so out of
ignorance.
> The real problem here is that for the condition to become chronic and
>show in the bones is that he would have had to eat parts of perhaps a
>dozen or so animals over a period of weeks. The group was most unlikely
>to have that many dogs.
What happens (to groups like that of Mawson in the Antarctic) is
that the weakest members of the group get sore gums and loose
teeth. So they are given the softest meat -- the liver, while
the stronger chew on the stringy muscle and sinew. The sick get
sicker, but no one understands the cause. Eating most of the
livers of three or four dogs over a few weeks would be enough to
kill you.
>What was most likely happening at this stage was
>that pups would be taken from wild flesh eaters and keep for a while as
>pets and maybe hunting companions. If food ran short they became lunch.
That's not the way things work. The vast majority of humans feel
a taboo against eating dog meat. This makes sense -- if a
society allows its working animals to be eaten when some
individuals get a bit peckish, then those animals will disappear.
There's a similar taboo against eating horse meat in this
country. There's one against beef in India. Such taboos only
break down in desperate situations.
Paul.
Paul Crowley
On Fri, 12 Jun 1998 22:09:36 -0500, "Dwight E. Howell"
<deo...@usit.net> wrote:
>Paul Crowley wrote:
>> Many modern people live in places where it's hard to get salt.
>> They have to live near it, or frequently travel distances to it,
>> or pay for it in one way or another. The question is: "Would
>> such an animal have evolved in such a location?" or "Would a
>> species without ready access to salt have evolved a mechanism
>> that required large quantities?"
>
>The answer is yes if the salt is there to be gotten.
If the costs of getting are high (and away from the coast they
usually are) then they wouldn't seek to waste it.
>We also don't have the ability to drink salty water or get rid of
>excess salt. Something needed in animals that live in salt water
>and useful in deserts.
I was not suggesting that we recently evolved from animals that
lived in water.
>Profuse
>sweating would be a big problem for a salt water creature unless it can
>drink salt water or had a good source of fresh water always available.
>It would still be a bad idea unless the pay off was big.
A species that developed heavy sweating as a cooling mechanism
must generally have had good sources of fresh water.
>> We must also have evolved in a habitat with warm nocturnal
>> temperatures, since we have no insulation against cold. Such fat
>> as we may have is in the wrong places. This is especially
>> noticeable in our children and infants. All such habitats are
>> close to the sea.
>
>Please work on the above. It does not seem to have a main idea or even
>belong together.
It all seems quite clear to me. Our heavy sweating (requiring a
lot of salt and fresh water) tells us that we evolved on the
littoral. This is confirmed by our absence of insulation,
especially on our small infants; they would die of hypothermia
if they spent nights anywhere that wasn't warm. The only places
that are warm at night are close to large bodies of water,
especially the sea.
Paul.
Paul Crowley
On Fri, 12 Jun 1998 22:18:38 -0500, "Dwight E. Howell"
<deo...@usit.net> wrote:
>Paul Crowley wrote:
>> If you are going to propose such a jump you need to say how and
>> why such a niche came into existence -- why there were no bovids
>> already eating that vegetation, or if there were, what advantages
>> the primate had over them. You also need to say why no modern
>> primate occupies that niche, or a closely related one.
>What happened to all other hominids seems to very plain and straight
>forward. We eliminated them. Even Gigantopithocus (sp) which was more
>related to Orangutans( sp). May be a few died from other environmental
>reasons but I would not wager on it.
Homo_sap (or its predecessors) would have eliminated competing
species in the same habitat. It wouldn't have touched a "marsh
hominid" or mangrove-swamp-hominid or savanna-hominid or
vegetation-eating-hominid anymore that it affected the other
large apes (before this century).
Paul.
Marc Verhaegen
Jukka Korpela heeft geschreven in bericht
<3582f844...@news.cs.hut.fi>...
>Dogs are wolves.
...
>I have never before seen such an estimate of 100,000 years.
V.Morell 1997 "The origin of dogs..." Sci.276:1647 gives ca.135,000 ya.
CurtAdams
crow...@hxtmail.cxm (Paul Crowley) writes:
>The only places
>that are warm at night are close to large bodies of water,
>especially the sea.
There are a lot of humans in the tropics who wish that bizarre
claim were actually true.
Curt Adams (curt...@aol.com)
"It is better to be wrong than to be vague" - Freeman Dyson
Paul Crowley
>Paul Crowley
>
>>>My "early association with dogs" hypothesis has been argued at
>>>length here. Apart from KNM-ER 1808 there's no good evidence either way.
>
>Paul, if you only have ER-1808, you could perhaps argue that there was an
>association between hypervit.A and Homo (erectus), but all this says
>absolutely nothing about the australopithecines.
>You must make the distinction. H.erectus is probably "close" to us (split
>probably at least 1 mya, cf. Neandertals/humans~500,000 ya), australopiths
>are much further related (probably more than 4 mya).
It's only partly a question as to how close they were to us. We
need an answer to how a slow, night-blind primate with a very low
rate of reproduction could survive on the ground against a wide
range of fearsome predators. And if you say they slept in the
trees like chimps, an account of how and why they diverged from
chimps, and when, why and how they completed the change
>There is the DNA "evidence" of dog domestication 100 kya.
The study by Wayne et al in Science last July identified four
clades of dogs, the oldest dating back 135 kya. This indicates
IMO a minimum date, and the existence of other clades, now
extinct, should be assumed.
>The LCA of living humans lived ca.150-100 kya ("Afr.Eve").
There's only one "clade" of humans now, but we don't rule out
others existing before 150 kya. I see a constant stream of
movement from the wild canid population to the domesticated one.
Bands of hominids would lose their dogs frequently (in
evolutionary time) through predation, disease, and often when
there was a famine. Sometimes they'd replace them from the wild.
>But, yes, why dog domestication 100 or perhaps 150 kya??
>- Cooperation in hunting, at first by accident? eg, humans (with fire? with
>spears?) driving herds of prey toward wolf packs? Then the wolves killed the
>prey animals at their side, the humans at the other side, and gradually they
>came closer & respected each other. Fire is probably older than 150 kya,
>spears/harpoons no doubt are older (400 kya German finds).
Wolves/dogs don't "respect" humans. That's the wrong way of
looking at it. Other species in such relationships don't
cogitate about it. Guppies and shrimps (that occupy the same
hole) don't "respect" each other. The relationship works, and
that's all. In any case, an animal that grows up wild is rarely
likely to want to associate with humans. But look at the pups.
Wolf/jackal/fox/wild-dog pups must have been adopted by hominids
on hundreds of thousands of occasions. The operation is trivial.
The question is what was the first occasion that it was likely to
"work". That is, when was it likely that wild canid pups,
brought up by hominids, stayed with them on becoming adult? The
arrangement would suit both species perfectly. The canids could
locate animals that hominids could kill, such as tortoises,
snakes, porcupines, ratels or pangolins. They could chase others
up small trees, or down small holes -- for the hominids to catch:
mongooses, smaller cats, monkeys and baboons. They would detect,
and often scare off, diurnal and nocturnal predators, including
other hominids.
Canids do form such associations with other species. Coyotes
routinely work with badgers in stable long-term partnerships.
My own opinion is that hominids formed that relationship as soon
as they began to sleep on the ground, around 4.9 mya, and that it
was a crucial part of their niche.
>- An African Eve branch leaving Africa ca.100 kya? (wolves live in Eurasia).
>But then, why did they only leave Africa 100 kya?
Other places were occupied by dangerous hominids (such as
Neanderthals) and they couldn't only overcome/replace them when
they had acquired significantly superior technology.
Paul.
Paul Crowley
>
>Paul Crowley >Marc Verhaegen
>
>
>>>Paul, do you mean ER-1808 died from acute hypervit.A?
>>>(this is not what Walker etc. said)
>>
>>It's what he says in his "The Wisdom of Bones".
>
>but not what he says in Nature 296:248 (1982).
Obviously by 1982 he had not made a serious investigation. His
book was published in 1996. See pages 128 ff.
>>My "early association with dogs" hypothesis has been argued at
>>length here. Apart from KNM-ER 1808 there's no good evidence
>>either way. But I have seen no other account that seriously
>>tries to explain the ability of hominids to survive devastating
>>predation (especially nocturnal predation) prior (or even after)
>>the acquisiton of fire.
>
>And devastating predation by dogs/wolves?? Why would you let you domesticate
>by your prey??
You'd tame the pups -- something that can be done for an enormous
range of species; herd animals that can accept a human as the
dominant member of the group are especially susceptible.
However, you have not answered the question (not that I really
expect an answer from anyone): "How did hominins avoid
devastating predation?"
>>Hopefully it will soon be possible to date, from DNA studies, the
>>relative atrophication of the human sense of smell. It could
>>only come from the relationship with canids.
>
>No, our poor olfaction is what is seen in aquatic mammals, eg, mysticetes
>have rudimentary olfactory bulbs, odontocetes have even less.
>The human olf.bulb is about one third that of chimps, and even chimps have
>smaller olf.bulbs than baboons. Our wading ancestors (mangrove swamps?)
>needed less olfaction than terrestrial relatives (baboons..), our diving
>ancestors needed even less.
You have to accept that human ancestors have been largely
terrestrial for a long time -- in that they spent a lot of time
on land where they were vulnerable to a large variety of
extremely effective predators. As soon as this started, their
olfaction would rapidly re-establish itself -- and should be
stronger than that of chimps that live in forests and sleep in
trees.
>There is the DNA evidence of dog domestication 100 kya.
Wayne's study gives the latest measurable date for the split.
Not the earliest. Further it's callibrated on the coyote/wolf
split dated to 1 mya. Wolves and coyotes have probably existed
as distinct species for many millions (?15+) of years. Those two
canid niches are quite separate and are replicated across several
continents. However all canids interbreed, including wolves and
coyotes, so 1 mya date for the "split" is simply what can be
measured.
>IMO our final reterrestrialisation (full bipedalism with basicranial flexion
>etc., no much diving any more, frequent hunting of large game) took place
>only ca.150 kya in Africa. From there they rapidly spread over Eurasia &
>wiped out other Homo species (neandertal, erectus).
1) How do you explain all the stone tools in non-marshy areas
during the last 2.5 Myr? And why should a marsh-ape have needed
such tools, and come to use and store them?
2) The post-cranial skeleton of Turkana boy is almost identical
to ours, so it's very hard to see how he could have lived in a
very different niche.
3) What drove the largely aquatic ape into extinction during the
last 150 kya? It was, presumably, widely distibuted occupying
mangrove and other swamps throughout the tropics. Homo_sap does
not use these and should have left its occupants largely
unmolested.
4) Why do we not show the least inclination to return to swamps?
We don't visit them on our holidays. In fact they strike us as
unpleasant, unhealthy, hostile places to which we are not in the
least adapted.
Paul.
Paul Crowley
On 14 Jun 1998 22:59:51 GMT, curt...@aol.com (CurtAdams) wrote:
>crow...@hxtmail.cxm (Paul Crowley) writes:
>
>>The only places
>>that are warm at night are close to large bodies of water,
>>especially the sea.
>
>There are a lot of humans in the tropics who wish that bizarre
>claim were actually true.
I should have said "the only places that are _consistently_ warm
at night are close to large bodies of water . . ".
While it can sometimes be very warm at night in the tropics, this
cannot be guarranteed for the whole year, even at sea level.
Continental temperatures can fall rapidly at night. That is the
main reason virtually all other mammals have fur.
Look at the size and shape of human infants up to, say, 4 years
old and think about the climate for which they evolved. They
clearly had a way of keeping warm at night in the open; that
could only have been in consistently warm ambient temperatures.
Of course, you could easily disprove my hypothesis -- just point
out some places, well away from the sea or large lakes, where the
temperature stays above 15 C every night throughout the year.
Paul.
CurtAdams
crow...@hxtmail.cxm (Paul Crowley) writes:
>Of course, you could easily disprove my hypothesis -- just point
>out some places, well away from the sea or large lakes, where the
>temperature stays above 15 C every night throughout the year.
The Congo, Amazonia, and almost anyplace in West Africa south of
the Sahara.
Also, you're neglecting something - the only problem human
infants have with chill is lack of fur. We have no evidence
that any hominid other than us lacked fur. For all we know
Neanderthal might have been as furry as the mythical Sasquatch.
H.N. used some clothing, I believe, but it was very cold where
they lived and ape fur would have been very inadequate.
Lorenzo L. Love
Paul Crowley wrote:
[snip]
> However, you have not answered the question (not that I really
> expect an answer from anyone): "How did hominins avoid
> devastating predation?"
>
[snip]
> Paul.
Here kitty, kitty.
Lorenzo
Marc Verhaegen
Paul Crowley heeft geschreven in bericht <3586a18...@news.indigo.ie>...
>>>>Paul, do you mean ER-1808 died from acute hypervit.A?
>>>>(this is not what Walker etc. said)
>>>
>>>It's what he says in his "The Wisdom of Bones".
>>
>>but not what he says in Nature 296:248 (1982).
>
>Obviously by 1982 he had not made a serious investigation. His
>book was published in 1996. See pages 128 ff.
I haven't read it. (Later..?)
(If it was vit.A intoxication, it was by eating fish, turtle, dugong... --
not dog!)
...
>You'd tame the pups.
Yes, that might be the most probable start of dog domestication -- but not
of eating dogs!
>However, you have not answered the question (not that I really
>expect an answer from anyone): "How did hominins avoid
>devastating predation?"
Paul, I really don't see your problem. What devastating predation???
- For the australopiths, +- the same problem as African apes.
- For Homo: When they still lived in the mangrove forests, they slept in the
branches. They fleed or jumped in the water when leopards or so were
approaching. When already more aquatic, see Derek Ellis 1991 "Is an aquatic
ape viable interms of marine ecology and primate behaviour?" Maggie Roede
ed. "The aquatic ape: fact of fiction?" Souvenir London.
>>>Hopefully it will soon be possible to date, from DNA studies, the
>>>relative atrophication of the human sense of smell. It could
>>>only come from the relationship with canids.
>>
>>No, our poor olfaction is what is seen in aquatic mammals, eg, mysticetes
>>have rudimentary olfactory bulbs, odontocetes have even less.
>>The human olf.bulb is about one third that of chimps, and even chimps have
>>smaller olf.bulbs than baboons. Our wading ancestors (mangrove swamps?)
>>needed less olfaction than terrestrial relatives (baboons..), our diving
>>ancestors needed even less.
>You have to accept that human ancestors have been largely
>terrestrial for a long time -- in that they spent a lot of time
>on land where they were vulnerable to a large variety of
>extremely effective predators.
Why do I have to accept such nonsense?? (What do you mean by "long time"?)
> As soon as this started, their
>olfaction would rapidly re-establish itself -- and should be
>stronger than that of chimps that live in forests and sleep in
>trees.
IMO thick skulls = frequent diving!
IOW H.sapiens is only "recently" "fully" ex-aquatic.
(Definitions??)
>>There is the DNA evidence of dog domestication 100 kya.
>
>Wayne's study gives the latest measurable date for the split.
>Not the earliest. Further it's callibrated on the coyote/wolf
>split dated to 1 mya. Wolves and coyotes have probably existed
>as distinct species for many millions (?15+) of years. Those two
>canid niches are quite separate and are replicated across several
>continents. However all canids interbreed, including wolves and
>coyotes, so 1 mya date for the "split" is simply what can be
>measured.
>
>>IMO our final reterrestrialisation (full bipedalism with basicranial
flexion
>>etc., no much diving any more, frequent hunting of large game) took place
>>only ca.150 kya in Africa. From there they rapidly spread over Eurasia &
>>wiped out other Homo species (neandertal, erectus).
Cf. Caesar killing 1 million of Gauls, or Spaniards killing Aztecs etc., or
Australians eliminating aboriginals (I just read D.Quammen 1996 "The song of
the dodo" Simon & Schuster NY).
>1) How do you explain all the stone tools in non-marshy areas during the
last 2.5 Myr? And why should a marsh-ape have needed such tools, and come
to use and store them?
Stone tools are always of Homo, never of "apes".
>2) The post-cranial skeleton of Turkana boy is almost identical to ours, so
it's very hard to see how he could have lived in a very different niche.
Why a very different niche??
>3) What drove the largely aquatic ape into extinction during the last 150
kya? It was, presumably, widely distibuted occupying mangrove and other
swamps throughout the tropics. H.sapiens does not use these and should have
left its occupants largely unmolested.
No aquatic "apes" the last 150 kya, but (semi)aquatic humans.
>4) Why do we not show the least inclination to return to swamps? We don't
visit them on our holidays. In fact they strike us as unpleasant,
unhealthy, hostile places to which we are not in the least adapted.
Of course: mangrove swamps = perhaps 4 mya.
WADING APES
(with thanks to Norm McPhail)
Previously, the anthropological consensus was that bipedalism first appeared
about four million years ago. New evidence now suggests that this date ought
to be set back by at least another four million years. The significance of
this new finding is that the stem hominid – the last common ancestor of the
African great apes (gorillas, chimpanzees and humans) – may have walked part
of the time on two legs.
For the most part, our human ancestors had to work within the same
biological constraints that other mammals do to this day. There is much to
be learned by comparing the parallel or convergent adaptations of different
animals in similar environments. Thus, we find that many evolutionary
insights can be gained by working comparatively.
Wading primates naturally adopt a bipedal gait in shallow water. Proboscis
monkeys cross stretches of water on two legs to reach other mangrove trees.
Lowland gorillas go wading on their hind legs through forest swamps to eat
sedges. In the same way, the earliest hominids might have become partial
bipedalists in the mangrove swamps. In our opinion, a basic hominid
population around the Red Sea gave rise to different offshoots that entered
the African inland following the rivers upstream. This led to
australopithecines and African apes, and finally humans.
Hylobatids (the lesser apes or gibbons) and pongids (the Asian great apes or
orang-utans) live in Asia, whereas hominids (humans, chimps and gorillas)
live in Africa. The ten-million-years-old Ankarapithecus from Anatolia
displayed features of both pongids and hominids (1). These data suggest that
pongids and hominids split in Asia, perhaps in the Near East. According to
the molecular evidence, pongids and hominids split some ten or eight million
years ago; the forebears of the gorillas and those of humans and chimps then
broke off about eight or six million years ago; the ancestors of the
chimpanzees and those of humans then separated between six and four million
years (2).
We think it is probable that the stem hominids lived in the mangrove forests
around the Red Sea. They might have partly fed on shellfish growing on the
mangrove trunks exposed at low tide. Note that long-chain poly-unsaturated
lipid ratios of tropical fish and shellfish are more similar to those in the
human brain than all other food sources (3). Presumably these hominid
ancestors had thick enamel, just as earlier Ankarapithecus(1) and later
Australopithecus did. Thick enamel is typical of capuchin monkeys or sea
otters that eat hard-shelled foods such as nuts or molluscs (4-5).
Tool use is seen in lots of animals. But the most obvious examples are the
capuchin monkeys, chimpanzees and sea otters. They all try to open
hard-shelled foods by hammering with hard objects. Sea otters and mangrove
capuchins crack shellfish with stones, the capuchins even use oyster shells
when stones are not available (4), and the chimpanzees and capuchins also
crack open nuts with stones. It thus seems likely that tool use, and
especially stone tool use, often began with shellfish or perhaps nut eating.
No doubt, the hominids, like mangrove capuchins and sea otters, manipulated
hard objects for opening nuts and oysters. Arguably, this was the beginning
of tool use.
The stem hominids must have crossed the Red Sea and entered Africa at some
time between ten and six million years ago, where they soon radiated into
the forebears of gorillas, chimpanzees and humans. Since fossilisation is
difficult in mangrove areas, only the inland offshoots are discovered in the
fossil record. Presumably, several branches went extinct. Many of these
inland branches evolved in parallel. We may expect that, as they followed
the rivers upstream, the shellfish in their diet was replaced by plant food
and they became gradually more herbivorous and terrestrial again.
The gorilla branch first colonised the African inland, possibly along the
Rift Valley. Eventually, they became herbivorous. The chimpanzee branch
followed and developed parallel features, but the chimps remained more
omni-frugivorous. Perhaps both branches became even more quadrupedal again.
Knuckle-walking in African apes is easily derivable from short-legged
bipedalism (6). Since their interlude of frequent wading and shellfish
collecting was probably short and partial, few traces would remain in
present-day chimpanzees and gorillas. Features like bipedal locomotion,
technological skills, dextrous hands and even enlarged brains might diminish
or disappear. In some ways, we can view many changes as a U-turn back to the
niche specialities that most primates occupy.
A.afarensis shows enamel microwear features for aquatic plant feeding
similar to mountain beavers and capybaras (7). They typically lived in
swale-like streamside gallery woodlands (8). This is where they might have
waded bipedally in search of swamp herbs and sedges. Lowland gorillas
frequently do this to this day in the shallow waters of tropical forest
clearings (9). Gradually A.boisei evolved smaller front teeth but much
broader back teeth with thick and heavily worn enamel. This suggests hard
woody or tough-shelled diets such as nuts, bark, reeds, cane and sedges.
In the meantime, a part of the population was left behind at the coasts.
Homo erectus-like people colonised the Indian Ocean shores, and already two
million years ago they even reached as far as Java. Over time, they had
improved their shellfish collection and preparation techniques. Stone use
and tool manipulation proceeded as a means of extracting the meat. In our
view, it is likely that this advanced their swimming and even their diving
capabilities (10).
Dextrous hands and large brains then helped them to occupy inland milieus.
Since about two million years ago, different Homo populations became, to
different degrees, fully terrestrial and long-legged bipeds. These lines
included ergaster and perhaps already rudolfensis in Africa, and erectus and
later neanderthalensis outside Africa. Finally, sapiens arrived.
1. B Algaput et al. 1996. A new specimen of Ankaar-pithcus meteai from the
Sinap Formation of central Anatolia. Nature 382, 349-351.
2. S Kumar, SB Hedges 1998. A molecular timescale for vertebrate evolution.
Nature 392, 917-920
3. CL Broadhurst, SC Cunnane, MA Crawford 1998. Rift Valley fish and
shellfish provided brain-specific nutrition for early Homo. Brit. J. Nutr.
79, 3-21.
4. MEB Fernandes 1991. Tool use and predation of oysters by the tufted
capuchin in brackish water mangrove swamp. Primates 32, 529-531.
5. A Walker 1981. Diet and teeth – dietary hypotheses and human evolution.
Phil. Trans. R. Soc. Lond. B 292, 57-64.
6. SJ Edelstein 1987. An alternative paradigm for hominoid evolution. Hum.
Evol. 2, 169-174.
7. PF Puech, F Cianfarani, H Albertini 1986. Dental microwear studies as an
indicator for plant food in early hominids. Hum. Evol. 1, 507-515.
8. SC Radosevich, GJ Retallack, M Taieb 1992. Reassessment of the
paleoenvironment and preservation of hominid fossils from Hadar, Ethiopia.
Am. J. phys. Anthrop. 87, 15-27.
9. D Chadwik 1995. Ndoki – last place on earth. Natl Geogr. 188, 2-43.
10. E Schagatay 1996. The human diving response – effects of temperature and
training. Univ. Lund.
Marc Verhaegen
CurtAdams >Paul Crowley
...
>Also, you're neglecting something - the only problem human infants have
with chill is lack of fur.
Human babies weigh twice as much as newborn gorillas, yet they are shorter
in length, but they are much much fatter.
>We have no evidence that any hominid other than us lacked fur.
Several apes have large naked areas, eg, naked chests in lowland gorillas,
"baldness" in common chimps, "beards" & hair distribution in orangs. SC Coon
(1954 "The story of man" Knopf NY) says that chimps before birth have head
hairs & brows like we.
>....H.N. used some clothing, I believe, but it was very cold where they
lived and ape fur would have been very inadequate.
Yes, there have been found Neandertal "needles", I believe.
Marc