David Attenborough & AAT
Marc Verhaegen
Father Christmas very kindly brought me David Attenborough's new book 'The
Life of Mammals' (based on the new BBC TV series), and there are a couple of
passages of interest (sorry if this has been mentioned before).
The first relates to Mario's otters' fur and salt: [Start quote] "In
Scotland, some otters live along the coast and regularly hunt in the sea.
This causes them an dditional though minor problem. If the sea water dries
on their fur, the salt clogs their sweat glands, so when they return to land
after a fishing trip, they usually wash temselves in the fresh-water that
accumulates in small pools in the peat bogs. "One species of otter,
however, spends all its life at sea. It lives all along the west coast of
North America from Alaska to California and it has taken its adaptations for
water-living several steps further. Sea otters have the thickest fur of any
species in the family. Indeed, it is the thickest fur produced by any
mammal, with a million filaments to the square inch. All the hairs on a
human being's head number only about a tenth as many. To exploit the
insulating potential of this fur to the full, sea otters spend time each day
lying on the surface of the sea, blowing into their under-fur to ensure that
it is always fully topped up with air. Their skin fits so loosely around
their body that they can pull almost every part of it within reach of their
mouths. Even so, living permanently in water saps a great deal of heat from
an otter's body and it has to eat prodigiously in order to remain warm.
Every day it consumes about a third of its own body weight. It is as if a
human being, in order not to starve, has to eat a hundred hamburgers daily.
" [...] Even the major step of giving birth at sea has been achieved without
substantial physical changes. The new-born babies cannot swim until they are
about ten weeks old, but this causes them few problems. They are so fat and
their fur is so woolly that they are naturally buoyant and when they are not
lying on their mother's stomach drinking her milk, they loll about quite
happily among the floating kelp straps." [End quote] Which all seems
to confirm what Mario has been saying very nicely.
The second passage relates to bipedalism and the AAT: [Start quote]
"There are few more contentious issues in the story of humanity's evolution
than the explanation of what it was that caused four-footed knuckle-walking
to be abandoned in favour of a two-footed stride. There are several
theories. Maybe it was to allow our ancestors to carry things in their
hands - food that they had just collected, a simple stone tool that had
taken some time and skill to chip into effective shape, or maybe an infant
that lacked the clasping hands and feet needed to cling to its mother like a
baby ape. Maybe it was to get a clearer view over grass-covered plains to
spot a stalking carnivore. Maybe, if the climate was as hot as some believe,
it was to minimise the amount of the body exposed directly to the sun out on
the open plains - just the shoulders and the top of the head, instead of the
whole length of the torso.
"There is yet another theory that was first proposed half a century ago and
is often dismissed by many as far-fetched. Nonetheless it still has its
adherents. Some six million years ago, this part of Africa was rent apart by
earth movements associated with the formation of the Rift Valley. Sea water
poured in from the Red Sea away to the north. Isolated patches of higher
ground turned into islands and great areas became shallow lagoons. If that
happened, then there would undoubtedly be a great deal of food to be
collected on the margins andin the shallows of such lagoons - shellfish,
crustaceans, small fish. Intelligent inquisitive primates would surely have
been quick to exploit such a new and rich food supply. Doubtless those early
hominoids would have soon discovered a way to crack open molluscs and tear
apart crustaceans just as capuchins and crab-eating macaques do today. Maybe
some went into deeper water to look for food or to reach new feeding grounds
on the shores of nearby islets. If they did, an upright stance would have
brought them great advantages, not the least of which was that it enabled a
female to carry her baby above the water. "A vivid picture of such a
scene in reality comes from some islands in the delta of the Congo. There
chimps that have been individually rescued from lives of deprived captivity
have been released in order that they may learn to fend for themselves in
the wild before they are given total liberty. While they are doing so, they
are provided with daily supplies of bananas. As the boats of those caring
for them approach every morning, the chimps wade out towards them
two-footedly, anxious for their bananas. The males sometimes hold their long
arms above their heads, with hands clasped. Females come too holding their
infants high on their chests. With the water supporting their body and
helping their balance, an upright stance comes easily to them and with their
shorter bowed ape-legs hidden by the water they look extraordinarily human,
except for their jutting jaws and low receding foreheads with heavy
eyebrow-ridges. In fact they look uncannily, eerily, like the many
reconstructions that have been made over the years of creatures that might
have been the link between apes and humanity. As these chimpanzees have
become more accustomed to their new, if temporary, homes, they have become
more confident in the water. It is usually said that chimps do not swim.
Perhaps that is the case in normal circumstances, but one at least of these
males has shown that if there is a need to do so, they certainly can. He has
now started to swim out, way beyond his depth to get to the food-carrying
boat first. "Could living near and occasionally in water have been the
circumstance which led mankind's ancestors to move from knuckle-walking to
full bipedalism? Proponents of the theory invoke several pieces of
anatomical evidence to suggest that humanity did indeed have an amphibious
phase. Human beings, compared to chimps and orangs, have next to no body
hair. Why did they lose it? In water, hair is a relatively ineffective
insulator. In consequence, many water-living mammals - seals, whales,
hippos - have lost theirs. Hair runs in tracts that form runnels down which
water trickles away. The tracts on the body of a four-footed animal run down
at right angles to its spine, across its flanks to its belly. Our hair
tracts, such as they are, however, are different. Instead of running roughly
parallel to our ribs, they run at right angles to them, down from our
shoulders parallel to our spine, suggesting that we were already standing
upright when our bodies were just as hairy as that of a chimpanzee. Our skin
differs from that of all other living apes in another way. It has abundant
sweat glands that produce an oily secretion. That too is an adaptation that
could be very valuable for a creature that lived in and out of water.
Particularly persuasive is the fact that when we develop fat, we accumulate
it in a layer immediately beneath our skin. The only other mammals that
develop subcutaneous layers of fat in this way are seals and whales - and
they do so to insulate themselves from the chilling water. If our ancestors
had spent a significant amount of time in the water, such a fat layer would
have been very valuable. "If that crucial shift in posture did indeed
happen when our remote ancestors were living in and around lagoons, it would
also help to explain how another important change occurred at this time - a
huge increase in the size of our ancestors' brains. Developing and operating
a brain takes a lot of energy. Fruits, seeds, roots and other vegetation are
sufficient to fuel ape-sized brains. We, however, have gigantic brains, by
far the largest in proportion to the size of our bodies of any species of
mammal. Keeping them functioning consumes 20% of all the energy that we get
from our food, even though our brain accounts for only 2% of our body
weight. Evolving a large brain could only have happened among creatures that
had an abundant supply of rich food. Shellfish would have provided exactly
that." [End quote]
Attenborough doesn't actually say that he endorses the AAT, but then he
doesn't have to. A few lines on some of the many conventional theories on
bipedalism, liberally sprinkled with 'maybe's, as against two pages or so on
AAT, plus a nice photo of a bipedal chimp in waist-deep water. We could
quibble over some of his details, but it is nice to see this in a book that
will sell millions of copies. Let's hope the appropriate section of the TV
program doesn't fudge the issue. --
Pauline Ross
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Mario Petrinovic
news:3e0af0d4$0$90233$ba62...@news.skynet.be...
> In water, hair is a relatively ineffective
> insulator. In consequence, many water-living mammals - seals, whales,
> hippos - have lost theirs.
Did I hear "seals"? -- Mario
Marc Verhaegen
"Mario Petrinovic" <mario.pe...@zg.tel.hr> wrote in message
news:auf63q$2k3m$1...@as201.hinet.hr...
> > In water, hair is a relatively ineffective insulator. In consequence,
many water-living mammals - seals, whales, hippos - have lost theirs.
> Did I hear "seals"? -- Mario
Yes, fur is rel.ineffective in water: it's compressed the deeper you dive,
and you have to groom it . Seals need a fur fot outside the water: on land
or on ice.
Marc
Mario Petrinovic
But it looks like he said that seals lost hair just like whales and
hippos did. To be honest, it never looked to me like some seals have much of
hair. True seals (which are living circumpolarly) have a lot of blubber and
sparse hair. Mediterranean monk seal (wnich lives close to equator) has the
least hair of all (AFAIK). -- Mario
Marc Verhaegen
> > > > In water, hair is a relatively ineffective insulator. In
consequence, many water-living mammals - seals, whales, hippos - have lost
theirs.
> > > Did I hear "seals"? -- Mario
> > Yes, fur is rel.ineffective in water: it's compressed the deeper you
dive, and you have to groom it. Seals need a fur fot outside the water: on
land or on ice. Marc
> But it looks like he said that seals lost hair just like whales and hippos
did. To be honest, it never looked to me like some seals have much of hair.
True seals (which are living circumpolarly) have a lot of blubber and sparse
hair. Mediterranean monk seal (wnich lives close to equator) has the least
hair of all (AFAIK). -- Mario
Sorry, Mario, I was absent-minded, yes, you're right: Attenborough is wrong
here of course: only elephant seals lack fur, and if he meant "pinnipeds",
only some very large pinnipeds lack fur: apart from elephant seals, only
male adult Steller's sealions & walruses, but these are no true seals. He
must have meant seacows? All fully aquatic mammals (=Sirenia+Cetacea) are
furless. In cold regions, very large semi-aquatics (>500-1000 kg) are
furless. In tropical regions, the medium-sized (>20-50 kg) semi-aquatics are
furless (eg, pygmy hippos, babirusas) but also some medium-sized
non-aquatics that spend a lot of time in burrows can be very sparsely-haired
(aardvarks, wrat hogs, hunting-dogs) & some very large non-burrowing
terrestrials are furless (all elephant species, most rhino species, but not,
eg, giraffes). Of small species, only fully fossorial ones are furless
(naked molerats). The negative connection with burrowing & water suggests
friction is correlated with furlessness. This is also seen in humans
(clothing).
Marc Verhaegen
http://www.onelist.com/community/AAT
http://allserv.rug.ac.be/~mvaneech/Verhaegen.html
Marc Verhaegen
> ... David Attenborough's new book 'The Life of Mammals' (based on the new
BBC TV series), ... The second passage relates to bipedalism and the AAT:
[Start quote] "There are few more contentious issues in the story of
humanity's evolution than the explanation of what it was that caused
four-footed knuckle-walking to be abandoned in favour of a two-footed
stride. There are several theories. Maybe it was to allow our ancestors to
carry things in their hands - food that they had just collected, a simple
stone tool that had taken some time and skill to chip into effective shape
Unlikely: the most tool-using & tool-making mammals are quadrupeds: sea
otters, capuchin monkeys.
> , or maybe an infant that lacked the clasping hands and feet needed to
cling to its mother like a baby ape. Maybe it was to get a clearer view over
grass-covered plains to spot a stalking carnivore.
Extremely unlikely: the carnivore will spot you more easily. If you want to
spot predators it's enough when you only now & then stand on 2 legs (cf.
Suricata).
> Maybe, if the climate was as hot as some believe, it was to minimise the
amount of the body exposed directly to the sun out on the open plains - just
the shoulders and the top of the head, instead of the whole length of the
torso.
Even more unlikely: if that were true, a lot of mammals would have run
bipedally. Besides it only works at midday.
> "There is yet another theory that was first proposed half a century ago
and is often dismissed by many as far-fetched.
Dismissed only by those who have themselves extremely far-fetched ideas of
human evolution.
> ... "Could living near and occasionally in water have been the
circumstance which led mankind's ancestors to move from knuckle-walking to
full bipedalism?
?? Knuckle-walking is recent: it's only seen in extant gorillas & chimps.
Fossil African hominids ca.4-2 Ma (Lucy, anamensis, boisei) had partial
knuckle-walking features. IOW, it's more likely the other way round:
knuckle-walking evolved from some sort of bipedalism (eg, as seen in the
bipedal+climbing short-legged apiths).
> Proponents of the theory invoke several pieces of anatomical evidence to
suggest that humanity did indeed have an amphibious phase. Human beings,
compared to chimps and orangs, have next to no body hair. Why did they lose
it? In water, hair is a relatively ineffective insulator. In consequence,
many water-living mammals - seals, whales, hippos - have lost theirs.
As Mario said, this is wrong: most seals have fur. Perhaps Attenborough
meant "seacows, whales, hippos"?
> Hair runs in tracts that form runnels down which water trickles away. The
tracts on the body of a four-footed animal run down at right angles to its
spine, across its flanks to its belly. Our hair tracts, such as they are,
however, are different. Instead of running roughly parallel to our ribs,
they run at right angles to them, down from our shoulders parallel to our
spine, suggesting that we were already standing upright when our bodies were
just as hairy as that of a chimpanzee. Our skin differs from that of all
other living apes in another way. It has abundant sweat glands that produce
an oily secretion ...
?? I thought eccrine sweating is rather watery. Not oily at all AFAIK?
Curious Amateur
>
snip
>All fully aquatic mammals (=Sirenia+Cetacea) are
>furless.
Incorrect:
Otariidae - Northern Fur Seal, Stellar Sea Lion, and California Sea Lion
Phocidae - Habor Seal, Ringed Seal, Gray Seal, Harp Seal, Bearded Seal,Hooded
Seal. (don't confuse short fur with no fur).
>In cold regions, very large semi-aquatics (>500-1000 kg) are
>furless.
Incorrect:
Ursus - Polar Bear.
In tropical regions, the medium-sized (>20-50 kg) semi-aquatics are
>furless (eg, pygmy hippos, babirusas) but also some medium-sized
>non-aquatics that spend a lot of time in burrows can be very sparsely-haired
>(aardvarks, wrat hogs, hunting-dogs)
Marc, how much time must be spent in a burrow to fit this description? And
neither hunting dogs nor wart hogs are "sparsely-haired", they're
short-haired, not 'no-haired'.
>& some very large non-burrowing
>terrestrials are furless (all elephant species, most rhino species, but not,
>eg, giraffes). Of small species, only fully fossorial ones are furless
>(naked molerats). The negative connection with burrowing & water suggests
>friction is correlated with furlessness. This is also seen in humans
>(clothing).
Marc, burrowing is not responsible for furlessness. Examine Rodentia which
probably includes the largest number of burrowing species. You could add
members of the weasel family as well, several of whom routinely hunt their
prey in burrows (spending more time in them than wart hogs and hunting dogs)..
You could also add members from Insectivora and Lagomorpha to this list.
Seems to me you don't get into true hairlessness when it comes to
Sirenia till you hit a rather large size:
Walrus - 2000+lbs
Northern Elephant Seal - 8000+lbs
Delphinidae is virtually hairless and comes in sizes that are comparable to
our own, but its form is so advanced along the line of aquatic development as
to make it hard to compare with humans.
Consider that Otariidae, the most recent of the Pinnipeds to go aquatic, are
furred. Phocidae is furred. To find un-furred pinnipeds you have to achieve a
body weight over 2000 pounds. To find un-furred fully aquatic species in our
weight category you have to look at the extreme aquatic developments in
Cetaceans.
In other words, Marc, nature does not give you a readily comparable example of
what you think happened to humans. All the more recent aquatic adaptations
(Pinnipeds beneath 2000 pounds) are furry, and all of them show far more
adaptation to an aquatic environment than humans. All of the hairless aquatic
mammals (Cetaceans and really large pinnipeds) show extreme aquatic
adaptation, far more than humans.
Burrowing does not lead to hairlessness (Rodentia, Insectivora, Lagomorpha,
Carnivora[weasels and badgers]).
Let's examine two really recent exploiters of the aquatic habitat: the
North American sea otter and the polar bear.
The sea otter spends almost all of its life at sea. It hardly ever lands. Its
skin is covered in fur packed so tight as to keep the water away from the
skin. Only the hind feet are webbed. It's about 5.5 feet long and weighs about
100 pounds (about the size of a ten year old child). It lives in shallow water
(about 200 feet of depth). It's at least as aquatic as any pinniped, spending
more time in the water.
The polar bear is semi-aqautic. It hunts on land and in the open water. It
lacks webbing, but can swim underwater. It is furred, and is the largest
terrestial carnivore extant.
Neither of these bolster your argument that somewhere down the ancestral tree
our ancestors had a semi-aquatic existence.
Let's look at the adaptations:
1. SC fat - supposed to insulate us against cold water, yet hypothermia is
still a challenge for swimmers. We allegedly waded in water, yet we have SC
fat all over (not just in the lower limbs). Easier to see SC fat as an
adaptation to assist us through times when food is lacking (and indeed this is
the most prevalent use of SC fat amongst modern humans).
2. Hairlessness - supposed to reduce our drag in the water. No
comparablly hairless aquatic or semi-aquatic mammal exists. Delphinidae are
far too developed and Pinnipeds have fur unless over 2000 pounds. Easier to
see hairlessness as a means of remaining cool (less heat retention, melanin
blocking UV radiation).
3. Webbing - supposed to improve swimming ability. Ask any swimmer if they
swim faster with their fingers spread open, revealing the web, or with their
fingers closed, turning their entire hand into a paddle. Webbing does not
improve upon the basic human ability to swim, and indeed is never used for
swimming by a competent swimmer. In the case of incompetent swimmers, webbing
does not prevent drowning. What appears to be webbing are the muscles of the
palm of the hand, somewhat enlarged compared to our simian cousins, providing
us with more surface area and power to provide our hands with a superior grip.
4. Holding breath - Despite claims to the contrary, animals do hold their
breath if they find themselves submerged in water. I've seen dogs hold their
breath so as to be silent as possible while trying to pick out a faint sound.
All animals, including humans, can panic, run out of air, and drown. However,
the immediate reaction is to hold their breath.
5. More sweat glands - Supposed to produce oily secretions which assist in
insulating the body and keeping it warm. Easier to see this as concomittant
with the loss of hair. Smaller hair follicles and roots provide more room for
sweat glands, which also assist the body in remaining cool through
evaporation. To stay warm humans smear fat upon their bodies. Long distance
swimmers still do this. Human sweat is inadequate for the task. In fact, the
insulating fat swimmers spread on their bodies is to plug up the sweat glands
and by preventing sweating cause the body's temperature to rise to compensate
for the loss of heat caused by contact with water.
So let's see what we have now: Hairlessness and more sweat glands to keep us
cooler suggests we were dealing with hot weather enough to thrive better by
adapting to it.
SC fat suggests an annual season where food is difficult to obtain.
'Webbing' suggests a development to provide our hands with a superior grip.
Holding breath is a trait we share with all air-breathing animals. No more
indicative of an aquatic existence than it is in any animal.
None of these adaptations improves our ability to exist in an aquatic
environment.
CA
Curious Amateur
snip (sorry, there were no credits for one of the sets of quotes)
>> Maybe, if the climate was as hot as some believe, it was to minimise the
>amount of the body exposed directly to the sun out on the open plains - just
>the shoulders and the top of the head, instead of the whole length of the
>torso.
>
>Even more unlikely: if that were true, a lot of mammals would have run
>bipedally.
And how would they have done that given their skeltal structure, Marc? Which
ones have hips/legs/rear feet that can be easily converted to bipedalism?
Simians have a long history of using their hips, legs and rear feet for an
upright position. Bipedalism is not such a big step beyond knuckle-walking.
>Besides it only works at midday.
When the sun is most intense.
snip
>> ... "Could living near and occasionally in water have been the
>circumstance which led mankind's ancestors to move from knuckle-walking to
>full bipedalism?
>
>?? Knuckle-walking is recent: it's only seen in extant gorillas & chimps.
>Fossil African hominids ca.4-2 Ma (Lucy, anamensis, boisei) had partial
>knuckle-walking features. IOW, it's more likely the other way round:
>knuckle-walking evolved from some sort of bipedalism (eg, as seen in the
>bipedal+climbing short-legged apiths).
I'd like to see you refute Owen Lovejoy's analysis of Lucy's method of
locomotion. Lucy was an obligate biped, not a knuckle-walker (not even
sometimes, the hip wouldn't allow it any better than it allows us to
knuckle-walk).
CA
Marc Verhaegen
"Curious Amateur" <no_...@home.guv> wrote in message
news:q2jP9.12455$%R6.7...@news20.bellglobal.com...
> >> Maybe, if the climate was as hot as some believe, it was to minimise
the amount of the body exposed directly to the sun out on the open plains -
just the shoulders and the top of the head, instead of the whole length of
the torso.
> >Even more unlikely: if that were true, a lot of mammals would have run
bipedally.
> And how would they have done that given their skeltal structure, Marc?
A lot of monkeys run sometimes on 2 legs, but savanna baboons are more
quadruped than forest ones.
> Which ones have hips/legs/rear feet that can be easily converted to
bipedalism?
Why do you think human hips... can "easily be converted to bipedalism"??
> Simians have a long history of using their hips, legs and rear feet for an
upright position.
Exactly. Savanna baboons are very quadruped.
> Bipedalism is not such a big step beyond knuckle-walking.
Beyond?? Why beyond? You probably mean KWing is not such a big step beyond
short-legged bipedalism as in apiths? It's the other way round of course:
KWers live today. Apiths (4-2 Ma) were less KWing than today's chimps &
gorillas (0 Ma). No doubt you know that KWing features have been described
in A.anamensis, afarensis & boisei?
> >Besides it only works at midday.
> When the sun is most intense.
Yes: it only works between say 11.30 am & 0.30 pm. A very short period, no
sensible man goes out then. And no savanna mammal stands on its hind legs at
noon. It's the most incredible idea I ever heard. "... the hypothesis of a
foraging or hunting male accords ill with the meridian theory of Wheeler
that our ancestors became bipedal to minimise direct solar radiation at
midday and retained a hairy heat shield only on top of the head (1984, 1988,
in imitation of D. H. K. Lee, in Newman, 1970; and in Schmidt-Nielsen 1974,
p. 89). If we accept this reasoning, it must have been the women who ranged
over the plains at noon while the balding and bearded males rested in the
shade."
> >> ... "Could living near and occasionally in water have been the
circumstance which led mankind's ancestors to move from knuckle-walking to
full bipedalism?
> >?? Knuckle-walking is recent: it's only seen in extant gorillas & chimps.
Fossil African hominids ca.4-2 Ma (Lucy, anamensis, boisei) had partial
knuckle-walking features. IOW, it's more likely the other way round:
knuckle-walking evolved from some sort of bipedalism (eg, as seen in the
bipedal+climbing short-legged apiths).
> I'd like to see you refute Owen Lovejoy's analysis of Lucy's method of
locomotion. Lucy was an obligate biped, not a knuckle-walker (not even
sometimes, the hip wouldn't allow it any better than it allows us to
knuckle-walk). CA
CA, you have a lot to read.
1) J.Clarke 2000 "What the StW 573 Australopithecus skeleton reveals about
early hominid bipedalism" AAPA abstracts:126: "... the foot had both bipedal
& climbing capabilities, whilst the arm & hand indicate adaptation to
arboreal locomotion. This skeleton's foot morphology is consistent with the
bipedal Laetoli footprint trails, which are not those of fully human feet,
but which have very clear ape-like morphology." What is "an obligate
biped"?? Is a wader-climber an obligate biped IYO?
2) Richmond & Strait 2000 Nature 404:382-5 say that Lucy (as well as
anamensis) had some KWing features.
3) The hip joint has not much to do with KWing. Leg length has. No doubt you
know that apiths had short legs, like African apes, unlike humans?
Marc Verhaegen
"Curious Amateur" <no_...@home.guv> wrote in message
> >All fully aquatic mammals (=Sirenia+Cetacea) are furless.
> Incorrect:
?? Sirenia & Cetacea are furless, no?
> Otariidae - Northern Fur Seal, Stellar Sea Lion, and California Sea Lion
Phocidae - Habor Seal, Ringed Seal, Gray Seal, Harp Seal, Bearded
Seal,Hooded Seal. (don't confuse short fur with no fur).
These are not furless, CA. Aren't you confusing something?? You do know they
spend an important part of their life on land or ice?
> >In cold regions, very large semi-aquatics (>500-1000 kg) are furless.
> Incorrect: Ursus - Polar Bear.
OK, thanks.
> >In tropical regions, the medium-sized (>20-50 kg) semi-aquatics are
furless (eg, pygmy hippos, babirusas) but also some medium-sized
non-aquatics that spend a lot of time in burrows can be very sparsely-haired
(aardvarks, wrat hogs, hunting-dogs)
> Marc, how much time must be spent in a burrow to fit this description? And
neither hunting dogs nor wart hogs are "sparsely-haired", they're
short-haired, not 'no-haired'.
OK, that would tend to restrict the furless ones to (semi)aquatic.
> >& some very large non-burrowing terrestrials are furless (all elephant
species, most rhino species, but not, eg, giraffes). Of small species, only
fully fossorial ones are furless (naked molerats). The negative connection
with burrowing & water suggests friction is correlated with furlessness.
This is also seen in humans (clothing).
> Marc, burrowing is not responsible for furlessness. Examine Rodentia which
probably includes the largest number of burrowing species. You could add
members of the weasel family as well, several of whom routinely hunt their
prey in burrows (spending more time in them than wart hogs and hunting
dogs).. You could also add members from Insectivora and Lagomorpha to this
list.
Reread what I said, CA: "in tropical regions".
(BTW, I listed furless mammals. Why would I add rabbits??)
> Seems to me you don't get into true hairlessness when it comes to Sirenia
till you hit a rather large size: Walrus - 2000+lbs Northern Elephant Seal -
8000+lbs
You do know what Sirenia are??
> Delphinidae is virtually hairless and comes in sizes that are comparable
to our own, but its form is so advanced along the line of aquatic
development as to make it hard to compare with humans.
Again: you are not following the argument. Cetacea are fully aquatic. The
time spent on land has no influence in fully aquatics.
> Consider that Otariidae, the most recent of the Pinnipeds to go aquatic,
are furred. Phocidae is furred. To find un-furred pinnipeds you have to
achieve a body weight over 2000 pounds. To find un-furred fully aquatic
species in our weight category you have to look at the extreme aquatic
developments in Cetaceans.
Again: make the distinction between tropical & non-tropical species. And
don't forget Steller sealions (<1000kg). Please re-read carelully what I
said.
> In other words, Marc, nature does not give you a readily comparable
example of what you think happened to humans.
Can you read my thoughts?? CA, re-read what I said: all I said about humans
was "clothing"! Clothing! Did I mention AAT??
> All the more recent aquatic adaptations (Pinnipeds beneath 2000 pounds)
are furry, and all of them show far more adaptation to an aquatic
environment than humans. All of the hairless aquatic mammals (Cetaceans and
really large pinnipeds) show extreme aquatic adaptation, far more than
humans.
Yes. So what?
> Burrowing does not lead to hairlessness (Rodentia, Insectivora,
Lagomorpha, Carnivora[weasels and badgers]).
Try to have a shaded view, CA. It's obvious that different factors are
involved, eg, body size, climate etc.
> Let's examine two really recent exploiters of the aquatic habitat: the
North American sea otter and the polar bear. The sea otter spends almost
all of its life at sea. It hardly ever lands. Its skin is covered in fur
packed so tight as to keep the water away from the skin. Only the hind feet
are webbed. It's about 5.5 feet long and weighs about 100 pounds (about the
size of a ten year old child). It lives in shallow water (about 200 feet of
depth). It's at least as aquatic as any pinniped, spending more time in the
water. The polar bear is semi-aqautic. It hunts on land and in the open
water. It lacks webbing, but can swim underwater. It is furred, and is the
largest terrestial carnivore extant. Neither of these bolster your
argument that somewhere down the ancestral tree our ancestors had a
semi-aquatic existence.
Again: if I had an "argument" in the above, it was "clothes"!
> Let's look at the adaptations: 1. SC fat - supposed to insulate us against
cold water, yet hypothermia is still a challenge for swimmers.
Not in tropical waters. Certainly not in fat people. To the contrary.
> We allegedly waded in water, yet we have SC fat all over (not just in the
lower limbs).
Human diving skills (not present in apes) clearly proves human ancestors
were parttime divers.
> Easier to see SC fat as an adaptation to assist us through times when food
is lacking (and indeed this is the most prevalent use of SC fat amongst
modern humans).
No, CA. All mammals lack food sometimes. Monkeys & apes have 10 times less
body fat than humans. Don't they lack food sometimes?
> 2. Hairlessness - supposed to reduce our drag in the water. No comparablly
hairless aquatic or semi-aquatic mammal exists. Delphinidae are far too
developed and Pinnipeds have fur unless over 2000 pounds. Easier to see
hairlessness as a means of remaining cool (less heat retention, melanin
blocking UV radiation).
See above.
> 3. Webbing - supposed to improve swimming ability. ...
Did I use that argument?? First define webbing. Syndactyly in hylobatids is
more likely for grasping branches. Dogs & cats & cows have webbing between
the toes. Just check your dog.
> 4. Holding breath - Despite claims to the contrary, animals do hold their
breath if they find themselves submerged in water. I've seen dogs hold their
breath so as to be silent as possible while trying to pick out a faint
sound. All animals, including humans, can panic, run out of air, and drown.
However, the immediate reaction is to hold their breath.
No dog or ape can hold its breath for several minutes. No dog or ape dives
tens of metres deep.
> 5. More sweat glands - Supposed to produce oily secretions which assist in
insulating the body and keeping it warm. Easier to see this as concomittant
with the loss of hair. Smaller hair follicles and roots provide more room
for sweat glands, which also assist the body in remaining cool through
evaporation. To stay warm humans smear fat upon their bodies. Long distance
swimmers still do this. Human sweat is inadequate for the task. In fact, the
insulating fat swimmers spread on their bodies is to plug up the sweat
glands and by preventing sweating cause the body's temperature to rise to
compensate for the loss of heat caused by contact with water.
1) Eccrine sweating is watery, not oily.
2) Thermoactive eccrine sweating is abundant in sealions & humans on land. I
have no examples of this in other mammals.
> So let's see what we have now: Hairlessness and more sweat glands to keep
us cooler
CA, you're making up your own "facts".
- Hairlessness: Don't you know that shaving off fur increases body
temperature in open places?
- Eccrine sweat glands cool off humans & sealions on land.
> suggests we were dealing with hot weather enough to thrive better by
adapting to it.
?? Please don't make up your own "facts".
> SC fat suggests an annual season where food is difficult to obtain.
Again: that's wishful thinking, CA. You are simply assuming what you want to
assume. Facts please. The only primates that have seasonal fat (not SC but
in the tail) are fat-tailed prosimians (estivation). Do you believe our
ancestors (since the Homo-Pan split) spent the summer sleeping in tree
holes??
> 'Webbing' suggests a development to provide our hands with a superior
grip.
Then why do dogs have webbing between the toes? what do dogs have to grasp?
> Holding breath is a trait we share with all air-breathing animals. No more
indicative of an aquatic existence than it is in any animal.
Completely wrong. Human breath hold is far superior to that of dogs or apes,
and superior to that of pigs, inferior to that of Cetacea, can best be
comparred to that of beavers (E.Schagatay 1996 "The human diving response:
effects of temperature and training" Univ.Lund Sweden).
> None of these adaptations improves our ability to exist in an aquatic
environment. CA
As I showed, breath-holding & SC fat are clear adaptations for spending more
time in water. Do you deny that ostriches had flying ancestors? Why don't
you give your own explanation why humans differ from chimps? Of course
ostriches are adapted to the lifestyle they live today, does that prevent
them from having flying ancestors?
Curious Amateur
This may make some of my answers here seem a bit out of context to the
material you've chosen to quote. My answers may make more sense if read
alongside the other things I said in my previous response to this thread.
In article <3e0e3d67$0$90227$ba62...@news.skynet.be>, "Marc Verhaegen"
<fa20...@skynet.be> wrote:
>
>"Curious Amateur" <no_...@home.guv> wrote in message
>news:q2jP9.12455$%R6.7...@news20.bellglobal.com...
>
>> >> Maybe, if the climate was as hot as some believe, it was to minimise
>the amount of the body exposed directly to the sun out on the open plains -
>just the shoulders and the top of the head, instead of the whole length of
>the torso.
>
>> >Even more unlikely: if that were true, a lot of mammals would have run
>bipedally.
>
>> And how would they have done that given their skeltal structure, Marc?
>
>A lot of monkeys run sometimes on 2 legs, but savanna baboons are more
>quadruped than forest ones.
I was asking about savannah quadrapeds like the hooved mammals. My point being
that to argue that all mammals would adopt bipedality ignores the fact that
most mammals are nowhere near ready to evolve into a bipedal form.
>> Which ones have hips/legs/rear feet that can be easily converted to
>bipedalism?
>
>Why do you think human hips... can "easily be converted to bipedalism"??
I don't understand this question. First, it is not an answer to my question.
Second, human hips are already bipedal.
>> Simians have a long history of using their hips, legs and rear feet for an
>upright position.
>
>Exactly. Savanna baboons are very quadruped.
When moving on the ground, in a forest or on the savannah, all simians are
quadrapeds. The amount of quadrapedalism depends upon the amount of time on
the ground compared to the amount of time in a tree. Since the savannah has
fewer trees than a forest, it is understandable that savannah babbons spend
more time on the ground than their forest cousins. Thus they spend more time
as quadrapeds than forest baboons.
Your argument does not contradict bipedalism in the savannah, Marc. It merely
demonstrates that an obligate quadraped, given fewer trees to climb, spends
more time on the ground.
>> Bipedalism is not such a big step beyond knuckle-walking.
>
>Beyond?? Why beyond? You probably mean KWing is not such a big step beyond
>short-legged bipedalism as in apiths? It's the other way round of course:
>KWers live today. Apiths (4-2 Ma) were less KWing than today's chimps &
>gorillas (0 Ma). No doubt you know that KWing features have been described
>in A.anamensis, afarensis & boisei?
Not according to Owen Lovejoy, who reconstructed the afarensis hip and did the
initial analysis with the actual specimens. I'm still waiting for you to
refute his analysis.
And shall I ask you where the knuckle indentations were in the castings
at Laetoli? While human-like footprints were evident, there was no sign of
knuckle-walking.
>
>
>
>
>> >Besides it only works at midday.
>
>> When the sun is most intense.
>
>Yes: it only works between say 11.30 am & 0.30 pm.
It depends upon season and lasts for longer than an hour, Marc. At any other
time the angle of the sun provides more opportunity for shade.
>A very short period, no sensible man goes out then.
"mad dogs and Englishmen" ;-)
But you are thinking of Europeans who are poorly suited for savannah life.
Africans do not have the same problems.
>And no savanna mammal stands on its hind legs at
>noon. It's the most incredible idea I ever heard.
I agree. But you were the one arguing that if it were advantageous to be
bipedal in the savannah then all the animals would become bipedal. You seem to
ignore the liklihood of ungulate hips evolving into bipedal hips.
>"... the hypothesis of a
>foraging or hunting male accords ill with the meridian theory of Wheeler
>that our ancestors became bipedal to minimise direct solar radiation at
>midday and retained a hairy heat shield only on top of the head (1984, 1988,
>in imitation of D. H. K. Lee, in Newman, 1970; and in Schmidt-Nielsen 1974,
>p. 89). If we accept this reasoning, it must have been the women who ranged
>over the plains at noon while the balding and bearded males rested in the
>shade."
I doubt balding was an issue, as these creatures were dying before 40 ;-)
As for beards, I tend to think of this as the result of sexual
selection, like the peacock's feathers.
>> >> ... "Could living near and occasionally in water have been the
>circumstance which led mankind's ancestors to move from knuckle-walking to
>full bipedalism?
>
>> >?? Knuckle-walking is recent: it's only seen in extant gorillas & chimps.
>Fossil African hominids ca.4-2 Ma (Lucy, anamensis, boisei) had partial
>knuckle-walking features. IOW, it's more likely the other way round:
>knuckle-walking evolved from some sort of bipedalism (eg, as seen in the
>bipedal+climbing short-legged apiths).
>
>> I'd like to see you refute Owen Lovejoy's analysis of Lucy's method of
>locomotion. Lucy was an obligate biped, not a knuckle-walker (not even
>sometimes, the hip wouldn't allow it any better than it allows us to
>knuckle-walk). CA
>
>CA, you have a lot to read.
>1) J.Clarke 2000 "What the StW 573 Australopithecus skeleton reveals about
>early hominid bipedalism" AAPA abstracts:126: "... the foot had both bipedal
>& climbing capabilities, whilst the arm & hand indicate adaptation to
>arboreal locomotion. This skeleton's foot morphology is consistent with the
>bipedal Laetoli footprint trails, which are not those of fully human feet,
>but which have very clear ape-like morphology."
Sorry, Marc, but that is not convincing enough. I am aware others debated the
issue. I am also aware that many of them met with Lovejoy at Johanson's
institute and their objections were blown away. I'll stand by Lovejoy's
assessment of afarensis' locomotion.
>What is "an obligate
>biped"?? Is a wader-climber an obligate biped IYO?
An "obligate biped" is one who, when on the ground, routinely walks on two
legs. As long as this is true, it doesn't matter whether the individual wades,
climbs, or swims.
>2) Richmond & Strait 2000 Nature 404:382-5 say that Lucy (as well as
>anamensis) had some KWing features.
Get back to me on this when either Lovejoy or Johanson claim such things.
>3) The hip joint has not much to do with KWing.
Wrong. Compare the hip of a human with that of a chimp, and then compare both
with afarensis. There is a big difference and the result is knuckle-walking
and a rolling gait in chimps.
>Leg length has.
By that argument you'd have pygmies walking like chimps, Marc. Midgets and
dwarves too.
It doesn't happen because they all have human hips. Leg length makes no
difference at all.
>No doubt you
>know that apiths had short legs, like African apes, unlike humans?
See above. Dwarves and midgets are routinely shorter than afarensis.
Marc, human children have the shortest human legs of all, much shorter than
afarensis. When was the last time you saw a knuckle-walking three year old
human child? They run around on two little legs, fully bipedal.
Please accept that leg length does not impose knuckle-walking on anything. It
doesn't affect midgets, dwarves, pygmies or little children, all of whom fit
within the limits of afarensis' leg length. If you want to argue that leg
length affected afarensis' locomotion and required knuckle-walking, then you
have to explain why none of those I've mentioned are affected.
The truth is it is the shape of the hip and the connection points between hip
and leg that result in knuckle-walking. The ape has to have a centre of
gravity far in front of the hip to make knuckle-walking work. In a
knuckle-walker, that centre of gravity falls between the centre of gravity of
a fully developed quadraped (say a horse) and the centre of gravity of a fully
bipedal creature (such as a human or ostrich).
CA
Marc Verhaegen
"AC" <sp...@nospam.com.invalid> wrote in message
news:slrnb0svm...@ts1.alberni.net...
> Namely, the fossil record.
Yes, the fossil record says Homo ergaster-erectus dispersed apparently in a
remarkably short time over southern Eurasia ca.1.8 Ma (fossils or tools of
that age in Algeria, Israel, Georgia, Java - IOW, this "fast" dispersal
happened along the coasts of the Mediterranean & Indian Ocean). The
subsequent sea level changes have usu. hindered fossilisation, but at some
places the seacoasts of that time can still be found, and here we find Homo
fossils amid shells, corals & barnacles (eg, Mojokerto Java ca.1.8 Ma).
IOW, the fossil record completely confirms the comparative evidence Alister
Hardy described in 1960 ("Was Man more aquatic in the past?" New Scientist):
how a sea-side lifestyle - incl. wading, swimming, collecting coconuts,
edible shells, turtles, crabs, seaweeds etc. - explains many typically human
features that are absent in chimps, and that are unexplained by all savanna
scenarios, eg, reduction of climbing skills, very large brain, greater
breathing control (= preadaptation for speech), very dextrous hands (stone
tool use to open nuts & shells), reduction of fur, thicker fat tissues,
longer legs, more linear body build, high needs of iodine, sodium,
poly-unsaturated fatty acids, etc.
The only problem is that many old savanna believers are so biased &
convinced of their Holy Savanna Theory (with no evidence at all BTW) that
don't want to see this & refuse to discuss the data. Luckily it's only the
less informed laymen that have these outdated savanna ideas that can still
be found in popular books. Many leading paleoanthropologists are wiser & are
more open-minded, eg, http://allserv.rug.ac.be/~mvaneech/outthere.htm
Curious Amateur
>
>"Curious Amateur" <no_...@home.guv> wrote in message
>news:tTiP9.12453$%R6.7...@news20.bellglobal.com...
>
>> >All fully aquatic mammals (=Sirenia+Cetacea) are furless.
>
>> Incorrect:
>
>?? Sirenia & Cetacea are furless, no?
>
>> Otariidae - Northern Fur Seal, Stellar Sea Lion, and California Sea Lion
>Phocidae - Habor Seal, Ringed Seal, Gray Seal, Harp Seal, Bearded
>Seal,Hooded Seal. (don't confuse short fur with no fur).
>
>These are not furless, CA. Aren't you confusing something??
Yes, confused Sirenia with Pinnpedia (whoops).
>You do know they
>spend an important part of their life on land or ice?
Important but not a lot of their life. Mating and birthing occur on land/ice,
usually for a few weeks. The rest of the year they are in the water.
You are not arguing that they are not fully aquatic, are you? Orcas beach
themselves to catch unwary seals. This does not reduce Orcas from being fully
aquatic.
>> >In cold regions, very large semi-aquatics (>500-1000 kg) are furless.
>
>> Incorrect: Ursus - Polar Bear.
>
>OK, thanks.
:-)
>> >In tropical regions, the medium-sized (>20-50 kg) semi-aquatics are
>furless (eg, pygmy hippos, babirusas) but also some medium-sized
>non-aquatics that spend a lot of time in burrows can be very sparsely-haired
>(aardvarks, wrat hogs, hunting-dogs)
>
>> Marc, how much time must be spent in a burrow to fit this description? And
>neither hunting dogs nor wart hogs are "sparsely-haired", they're
>short-haired, not 'no-haired'.
>
>OK, that would tend to restrict the furless ones to (semi)aquatic.
Not entirely, but certainly primarily.
>> >& some very large non-burrowing terrestrials are furless (all elephant
>species, most rhino species, but not, eg, giraffes). Of small species, only
>fully fossorial ones are furless (naked molerats). The negative connection
>with burrowing & water suggests friction is correlated with furlessness.
>This is also seen in humans (clothing).
>
>> Marc, burrowing is not responsible for furlessness. Examine Rodentia which
>probably includes the largest number of burrowing species. You could add
>members of the weasel family as well, several of whom routinely hunt their
>prey in burrows (spending more time in them than wart hogs and hunting
>dogs).. You could also add members from Insectivora and Lagomorpha to this
>list.
>
>Reread what I said, CA: "in tropical regions".
You don't think they have Rodentia, Insectivora, and Lagomorpha in tropical
regions? And aren't elephants and rhinos savannah creatures?
>(BTW, I listed furless mammals. Why would I add rabbits??)
You argued a relationship between burrowing and hairlessness. Rabbits are
burrowing animals and are not furless.
>
>
>> Seems to me you don't get into true hairlessness when it comes to Sirenia
>till you hit a rather large size: Walrus - 2000+lbs Northern Elephant Seal -
>8000+lbs
>
>You do know what Sirenia are??
Dugongs and manatees. Its been awhile since I had to recall such things ;-)
>> Delphinidae is virtually hairless and comes in sizes that are comparable
>to our own, but its form is so advanced along the line of aquatic
>development as to make it hard to compare with humans.
>
>Again: you are not following the argument. Cetacea are fully aquatic. The
>time spent on land has no influence in fully aquatics.
>
>
>> Consider that Otariidae, the most recent of the Pinnipeds to go aquatic,
>are furred. Phocidae is furred. To find un-furred pinnipeds you have to
>achieve a body weight over 2000 pounds. To find un-furred fully aquatic
>species in our weight category you have to look at the extreme aquatic
>developments in Cetaceans.
>
>Again: make the distinction between tropical & non-tropical species. And
>don't forget Steller sealions (<1000kg). Please re-read carelully what I
>said.
Stellers are not furless.
>> In other words, Marc, nature does not give you a readily comparable
>example of what you think happened to humans.
>
>Can you read my thoughts?? CA, re-read what I said: all I said about humans
>was "clothing"! Clothing! Did I mention AAT??
Do you need to mention AAT for me to make an independent observation, Marc?
Yes in fat people, Marc. They too suffer hypothermia (poor circulation, if
nothing else). As for tropical waters not causing hypothermia, if true then
there was no need to develop SC fat for the sake of being semi-aquatic.
>
>> We allegedly waded in water, yet we have SC fat all over (not just in the
>lower limbs).
>
>Human diving skills (not present in apes) clearly proves human ancestors
>were parttime divers.
Human diving skills (which are _not_ inherited, by the way) just shows we
learned how to jump in the water with style. It certainly does not demonstrate
any physical adaptation to water.
>> Easier to see SC fat as an adaptation to assist us through times when food
>is lacking (and indeed this is the most prevalent use of SC fat amongst
>modern humans).
>
>No, CA. All mammals lack food sometimes. Monkeys & apes have 10 times less
>body fat than humans. Don't they lack food sometimes?
Obviously not, or we'd find a lot of starved monkeys dead, wouldn't we?
You've discounted the need for SC fat in tropical waters (no hypothermia), and
you've discounted the need for SC fat to protect the organism through times of
hunger (which is what SC fat is used for today by most humans). So what is
your explanation for SC fat?
>> 3. Webbing - supposed to improve swimming ability. ...
>
>Did I use that argument?? First define webbing. Syndactyly in hylobatids is
>more likely for grasping branches. Dogs & cats & cows have webbing between
>the toes. Just check your dog.
So we are agreed that webbing has nothing to do with a proposed aquatic
existence.
>> 4. Holding breath - Despite claims to the contrary, animals do hold their
>breath if they find themselves submerged in water. I've seen dogs hold their
>breath so as to be silent as possible while trying to pick out a faint
>sound. All animals, including humans, can panic, run out of air, and drown.
>However, the immediate reaction is to hold their breath.
>
>No dog or ape can hold its breath for several minutes. No dog or ape dives
>tens of metres deep.
The polar bear does. And until you can come up with a reason for a dog or ape
to either of the above, I'd say you can't get them to do it because they can't
figure out why they should.
In other words, it could just as easily be a lack of motive or ability to
comprehend the need as it could be an inability.
At any rate, you are quibbling over minutes and meters, and ignoring the fact
they can and do hold their breath. If we are going to quibble over minutes and
metres, then let's use the sperm whale as our standard rather than humans ;-)
With such a standard, humans are not much better than dogs or apes.
>
>
>> 5. More sweat glands - Supposed to produce oily secretions which assist in
>insulating the body and keeping it warm. Easier to see this as concomittant
>with the loss of hair. Smaller hair follicles and roots provide more room
>for sweat glands, which also assist the body in remaining cool through
>evaporation. To stay warm humans smear fat upon their bodies. Long distance
>swimmers still do this. Human sweat is inadequate for the task. In fact, the
>insulating fat swimmers spread on their bodies is to plug up the sweat
>glands and by preventing sweating cause the body's temperature to rise to
>compensate for the loss of heat caused by contact with water.
>
>1) Eccrine sweating is watery, not oily.
>2) Thermoactive eccrine sweating is abundant in sealions & humans on land. I
>have no examples of this in other mammals.
Try horses and cattle.
>> So let's see what we have now: Hairlessness and more sweat glands to keep
>us cooler
>
>CA, you're making up your own "facts".
Hardly.
>- Hairlessness: Don't you know that shaving off fur increases body
>temperature in open places?
I have a friend who shaves his beard and close-crops his hair every summer to
cool down. Exposing more skin to wind allows for faster evaporation of sweat,
and thus cools down the body. Anyone whose worn clothing on a hot day, and
then had the chance to "peel" some of it off will appreciate the loss of
"fur".
>- Eccrine sweat glands cool off humans & sealions on land.
>
>> suggests we were dealing with hot weather enough to thrive better by
>adapting to it.
>
>?? Please don't make up your own "facts".
Marc, these "made-up" facts are personal experiences of mine or those I've
known. These are repeatable experiments.
>> SC fat suggests an annual season where food is difficult to obtain.
>
>Again: that's wishful thinking, CA. You are simply assuming what you want to
>assume. Facts please. The only primates that have seasonal fat (not SC but
>in the tail) are fat-tailed prosimians (estivation). Do you believe our
>ancestors (since the Homo-Pan split) spent the summer sleeping in tree
>holes??
SC fat is created during times of plenty, and are depleted through times of
hunger. Ask your doctor, Marc. It doesn't take Einstein to figure out that
this ability helps an organism make best use of the resources. Bears routinely
do this every year, laying on fat for the winter hibernation when they will
burn a considerable amount of fat keeping warm and alive without eating.
Simians lacking this adaptation obviously have a reasonably reliable
year-round supply of food. They have no need to stock up on food energy for
times of crisis.
>> 'Webbing' suggests a development to provide our hands with a superior
>grip.
>
>Then why do dogs have webbing between the toes? what do dogs have to grasp?
Webbing helps them to keep their toes together and pointed in the same
direction, important for long chases.
>> Holding breath is a trait we share with all air-breathing animals. No more
>indicative of an aquatic existence than it is in any animal.
>
>Completely wrong. Human breath hold is far superior to that of dogs or apes,
>and superior to that of pigs, inferior to that of Cetacea, can best be
>comparred to that of beavers (E.Schagatay 1996 "The human diving response:
>effects of temperature and training" Univ.Lund Sweden).
Which only shows we can be convinced to do something others are unwilling to
do. This does not demonstrate an inability in animals, only an unwillingness.
Unless these scientists were willing to do something as inhuman as to drwon
these poor creatures to see how long they'd hold their breath, I'd question
the results as indicating a problem with motivating the animal in question.
>> None of these adaptations improves our ability to exist in an aquatic
>environment. CA
>
>As I showed, breath-holding & SC fat are clear adaptations for spending more
>time in water.
Actually, you've shown that SC fat had nothing to do with tropical waters (no
hypothermia), and unless this ability appeared in humans after they left
Africa and entered temperate waters, it has nothing to do with an aquatic
existence at all.
With breath-holding all you've demonstrated is it is very difficult for humans
to motivate animals to hold their breath.
>Do you deny that ostriches had flying ancestors?
I haven't given it any thought, to be honest, and unless there are compelling
reasons to associate ostriches with a flying ancestor I believe it is possible
for the ostrich to derive from a terrestrial bird. Did it occur to you that
flightless birds (ie dinosaurs) are the primitive version of birds? Where do
you draw the line between a feathered, flightless dinosaur and a feathered,
flightless bird? Back at the split there was very little difference at all.
>Why don't
>you give your own explanation why humans differ from chimps?
I've been doing that, Marc. Read some of my other articles.
>Of course
>ostriches are adapted to the lifestyle they live today, does that prevent
>them from having flying ancestors?
No, it doesn't.
And you make a great argument there too. Just as an ostrich can have a flying
ancestor, a Human with sc fat and furlessness can have an ancestor that had
neither.
CA
Marc Verhaegen
"Curious Amateur" <no_...@home.guv> wrote in message
> >> >All fully aquatic mammals (=Sirenia+Cetacea) are furless.
> >> Incorrect:
> >?? Sirenia & Cetacea are furless, no?
> >> Otariidae - Northern Fur Seal, Stellar Sea Lion, and California Sea
Lion Phocidae - Habor Seal, Ringed Seal, Gray Seal, Harp Seal, Bearded
Seal,Hooded Seal. (don't confuse short fur with no fur).
> >These are not furless, CA. Aren't you confusing something??
> Yes, confused Sirenia with Pinnpedia (whoops).
OK.
> >You do know they spend an important part of their life on land or ice?
> Important but not a lot of their life. Mating and birthing occur on
land/ice, usually for a few weeks. The rest of the year they are in the
water.
Yes, if they die of cold during those weeks... I'm only suggesting they need
the fur for this crucial time on land.
> >You are not arguing that they are not fully aquatic, are you? Orcas beach
themselves to catch unwary seals. This does not reduce Orcas from being
fully aquatic.
Again confusing something, CA?
- Orcas=cetaceans, fully aquatic.
- Pinnipeds=seals etc.: birthing on land or ice.
> >> >In cold regions, very large semi-aquatics (>500-1000 kg) are furless.
> >> Incorrect: Ursus - Polar Bear.
> >OK, thanks.
> :-)
> >> >In tropical regions, the medium-sized (>20-50 kg) semi-aquatics are
furless (eg, pygmy hippos, babirusas) but also some medium-sized
non-aquatics that spend a lot of time in burrows can be very sparsely-haired
(aardvarks, wrat hogs, hunting-dogs)
> >> Marc, how much time must be spent in a burrow to fit this description?
And neither hunting dogs nor wart hogs are "sparsely-haired", they're
short-haired, not 'no-haired'.
> >OK, that would tend to restrict the furless ones to (semi)aquatic.
> Not entirely, but certainly primarily.
OK.
> >> >& some very large non-burrowing terrestrials are furless (all elephant
species, most rhino species, but not, eg, giraffes). Of small species, only
fully fossorial ones are furless (naked molerats). The negative connection
with burrowing & water suggests friction is correlated with furlessness.
This is also seen in humans (clothing).
> >> Marc, burrowing is not responsible for furlessness. Examine Rodentia
which probably includes the largest number of burrowing species. You could
add members of the weasel family as well, several of whom routinely hunt
their prey in burrows (spending more time in them than wart hogs and hunting
dogs).. You could also add members from Insectivora and Lagomorpha to this
list.
> >Reread what I said, CA: "in tropical regions".
> You don't think they have Rodentia, Insectivora, and Lagomorpha in
tropical regions?
Please re-read carefully: I also said: "medium-sized". Why do you believe
mutiple factors can't be involved?
> And aren't elephants and rhinos savannah creatures?
1 of 5 species of rhinos lives in open terrain.
1 of 3 species of elephants.
> >(BTW, I listed furless mammals. Why would I add rabbits??)
> You argued a relationship between burrowing and hairlessness.
I was listing the naked or sparsely haired mammals, remember?
> > Rabbits are burrowing animals and are not furless.
Of course: not: probably size.
> >> Seems to me you don't get into true hairlessness when it comes to
Sirenia till you hit a rather large size: Walrus - 2000+lbs Northern
Elephant Seal -8000+lbs
> >You do know what Sirenia are??
> Dugongs and manatees. Its been awhile since I had to recall such things
;-)
OK.
> >> Delphinidae is virtually hairless and comes in sizes that are
comparable to our own, but its form is so advanced along the line of aquatic
development as to make it hard to compare with humans.
> >Again: you are not following the argument. Cetacea are fully aquatic. The
time spent on land has no influence in fully aquatics.
> >> Consider that Otariidae, the most recent of the Pinnipeds to go
aquatic, are furred. Phocidae is furred. To find un-furred pinnipeds you
have to achieve a body weight over 2000 pounds. To find un-furred fully
aquatic species in our weight category you have to look at the extreme
aquatic developments in Cetaceans.
> >Again: make the distinction between tropical & non-tropical species. And
don't forget Steller sealions (<1000kg). Please re-read carelully what I
said.
> Stellers are not furless.
Females & young, yes, but as you could read above, I meant the adult male
Steller sealions are furless. Except for the manes. (Adult male Stellers &
humans have some astonishing parallels compared to their terrestrial
relatives (weasels & monkeys resp.): larger body weight, loss of fur except
manes, thick SC fat, elongated body, eccrine thermoactive sweating.)
> >> In other words, Marc, nature does not give you a readily comparable
example of what you think happened to humans.
> >Can you read my thoughts?? CA, re-read what I said: all I said about
humans was "clothing"! Clothing! Did I mention AAT??
> Do you need to mention AAT for me to make an independent observation,
Marc?
An observation?? Can you read my mind? What do you think I think happened to
humans?? Again: IMO the comparisons of furless mammals could suggest that
extant humans are (still) furless because they wear clothes. Have you given
1 argument why that should be wrong?
> >> All the more recent aquatic adaptations (Pinnipeds beneath 2000 pounds)
are furry, and all of them show far more adaptation to an aquatic
environment than humans. All of the hairless aquatic mammals (Cetaceans and
really large pinnipeds) show extreme aquatic adaptation, far more than
humans.
> >Yes. So what?
> >> Burrowing does not lead to hairlessness (Rodentia, Insectivora,
Lagomorpha, Carnivora[weasels and badgers]).
> >Try to have a shaded view, CA. It's obvious that different factors are
involved, eg, body size, climate etc.
> >> Let's look at the adaptations: 1. SC fat - supposed to insulate us
against cold water, yet hypothermia is still a challenge for swimmers.
> >Not in tropical waters. Certainly not in fat people. To the contrary.
> Yes in fat people, Marc. They too suffer hypothermia (poor circulation, if
nothing else).
I think you should inform a bit, CA. Humans display a SC layer of white fat
tissue, fairly evenly distributed over the surface of the central body parts
& comprising on average around 20 % of body weight. This fat layer is
conspicuously absent in savannah mammals & conspicuously common in the
larger aquatic ones, and demonstrably maladaptive in a hot terrestrial
environment. There are no fat animals on the savannah, with the
exception of small burrowing rodents or marsupials. In the case of these
species, the fat is brown rather than white, internal or localised (eg, in a
fat tail) rather than SC and, unlike human fat, it is subject to seasonal
fluctuation. Among larger animals, the dromedary has occasional need of a
fat store against food shortage, but here again the fat is highly
concentrated (in the hump), varies with the animal's feeding condition, and
fluctuates between 0.5 - 8 % of its body weight. The only fat animal which
exploits the grasslands around the rivers is the hippo, but it does this at
night (stays in the water during the day). In the case of marine mammals,
OTOH, the fat tissue is universal among the larger species. It varies from
20 to 25 % of the body weight in fast swimmers to more than 40 % in the
slower species. The adaptiveness of this feature in water has been further
illustrated by studies of human athletes, eg, blacks - in whom SC fat
comprises a somewhat lower % of overall body weight than in other
populations - tend to be the swiftest runners over both short & long
distances, but they are relatively poor swimmers. Successful swimmers are on
average fatter than the winners of track events; many long-distance swimmers
are even grossly fat (Pugh & Edholm 1955). The fat layer has been shown to
be an effective barrier against heat loss in water. A study of a fat Channel
swimmer revealed that when lying still in bath water at 18°C for more than
one hour, he complained of no discomfort other than boredom, whereas another
subject with much less SC fat complained of intense discomfort and showed a
drastic drop in rectal temperature after 15 minutes (ibid.). Clearly, the
possession of the fat layer facilitates spending more time in the water. The
result of one recent experiment even suggested that the converse may also be
true. It was found in a study of slightly obese women that, without dietary
restriction, an hour's daily walking or cycling reduced body weight by 10 &
12 % resp. after 6 months, while a daily swim caused a weight gain of 3 %
over the same period (Gwinup 1987). On land, OTOH, SC fat has the dual
disadvantage of reducing speed and, in hot climates, of acting as a heat
trap. An extra weight of fat tissue equivalent to only 10 % of body weight
seriously reduces speed. Even in temperate climates, no terrestrial animal
that has to run for its life - be it as predator or prey - has much fat.
Hares, eg, which escape predators by running, have much less body fat than
rabbits, which take refuge in their burrows. Excess fat can constitute a
real risk to humans taking exercise, especially in hot and sunny
environments (Austin & Lanking 1986). It has been calculated that most
land-based sports other than walking & table tennis are up to 10 times more
likely to lead to fatalities than swimming, despite the additional danger of
drowning incurred by swimmers (Dolmans 1987). And the same fat layer that is
advantageous in water, with its high thermal conductivity, is a handicap to
effective temperature control on-land. Stranded dolphins, even in cool
environments, soon die of hyperthermia; Pribilof fur seals are seriously
distressed by any activity on land at air temperatures of only 10°C. The
alleged danger of overheating on the savannah - sometimes advanced as the
reason for hairlessness - would have been compounded by the evolution of the
fat layer.
> As for tropical waters not causing hypothermia, if true then there was no
need to develop SC fat for the sake of being semi-aquatic.
Circular reasoning. Humans have no problems with hyper- nor hypothermia when
they spend the whole day in tropical water (ca.27°C). With the SC they have,
CA.
> >> We allegedly waded in water, yet we have SC fat all over (not just in
the lower limbs).
(When you're wading, you do that for feeding, the food is in the water, CA,
you have to dive or dip sometimes, don't you think?)
> >Human diving skills (not present in apes) clearly proves human ancestors
were parttime divers.
> Human diving skills (which are _not_ inherited, by the way
They _are_, CA. Ever seen a chimp dive?
>) just shows we learned how to jump in the water with style. It certainly
does not demonstrate any physical adaptation to water.
That's new. Just like climbing abilities (eg, of monkeys (not inherited
IYO??)) do not illustrate any physical adaptation to the trees?? Please, CA,
a bit serious.
> >> Easier to see SC fat as an adaptation to assist us through times when
food is lacking (and indeed this is the most prevalent use of SC fat amongst
modern humans).
> >No, CA. All mammals lack food sometimes. Monkeys & apes have 10 times
less body fat than humans. Don't they lack food sometimes?
> Obviously not, or we'd find a lot of starved monkeys dead, wouldn't we?
Is this an answer? Do you have 1 reason to think humans are more prone to
starvation than monkeys?? Or do you have a better reason why humans are 10
times fatter than monkeys or apes or dogs?
> You've discounted the need for SC fat in tropical waters (no hypothermia
No, re-read what I said: humans have no troubles with hyper- nor hypothermia
when they spend the whole day in tropical water (ca.27°C). With the SC they
have, CA.
>), and you've discounted the need for SC fat to protect the organism
through times of hunger (which is what SC fat is used for today by most
humans).
I did not. I only said that was an unlikely explanation why it evolved
originally: why don't chimps have SC fat to protect them in times of
hunger??
> So what is your explanation for SC fat?
A rudiment of beach-combers of course. What else?
> >> 3. Webbing - supposed to improve swimming ability. ...
> >Did I use that argument?? First define webbing. Syndactyly in hylobatids
is more likely for grasping branches. Dogs & cats & cows have webbing
between the toes. Just check your dog.
> So we are agreed that webbing has nothing to do with a proposed aquatic
existence.
As usual, it's more shaded than you think, CA, but I did not use that
argument here. You can find my view on this, eg, in my paper "Aquatic versus
savanna: comparative and paleo-environmental evidence" Nutrition and Health
9:165-191, 1993.
> >> 4. Holding breath - Despite claims to the contrary, animals do hold
their breath if they find themselves submerged in water. I've seen dogs hold
their breath so as to be silent as possible while trying to pick out a faint
sound. All animals, including humans, can panic, run out of air, and drown.
However, the immediate reaction is to hold their breath.
> >No dog or ape can hold its breath for several minutes. No dog or ape
dives tens of metres deep.
> The polar bear does. And until you can come up with a reason for a dog or
ape to either of the above, I'd say you can't get them to do it because they
can't figure out why they should.
Exactly, dogs or apes should not because they never dived as our ancestors
did. Polar bears OTOH dive for food.
> In other words, it could just as easily be a lack of motive or ability to
comprehend the need as it could be an inability.
No, inform: it's an inability, our precentral cortex is larger than in
chimps, largely due to the much larger representation of the breathing
musculature.
> At any rate, you are quibbling over minutes and meters, and ignoring the
fact they can and do hold their breath. If we are going to quibble over
minutes and metres, then let's use the sperm whale as our standard rather
than humans ;-)
That's very unfair, CA:
1) Holding your breath say some 50 times longer is "quibbling"?? Being able
to dive some 50 times deeper is "quibbling"?? Please a bit serious. Max.
breath hold diving is now more than 7 minutes. 7 minutes! Depth record is
over 100 m.
2) Did we ever claim human ancestors lived like sperm whales?? Again: our
view: a sea-side lifestyle - incl. wading, swimming, collecting edible
shells, turtles, crabs, coconuts, seaweeds etc. - easily explains many
typically human features that are absent in chimps, features that are
unexplained by the diverse savanna scenarios: reduction of climbing skills,
very large brain, greater breathing control, very dextrous hands (stone tool
use to open shells or nuts), reduction of fur, thicker fat tissues, longer
legs, more linear body build, high needs of iodine, sodium, poly-unsaturated
fatty acids etc. What's wrong with that? You still have to give your first
argument why our view would be wrong.
> With such a standard, humans are not much better than dogs or apes.
I estimate some 50 times. Not important to you?? Please...
> >> 5. More sweat glands - Supposed to produce oily secretions which assist
in insulating the body and keeping it warm. Easier to see this as
concomittant with the loss of hair. Smaller hair follicles and roots provide
more room for sweat glands, which also assist the body in remaining cool
through evaporation. To stay warm humans smear fat upon their bodies. Long
distance swimmers still do this. Human sweat is inadequate for the task. In
fact, the insulating fat swimmers spread on their bodies is to plug up the
sweat glands and by preventing sweating cause the body's temperature to rise
tocompensate for the loss of heat caused by contact with water.
> >1) Eccrine sweating is watery, not oily.
No answer?
> >2) Thermoactive eccrine sweating is abundant in sealions & humans on
land. I have no examples of this in other mammals.
> Try horses and cattle.
Please inform me... No, CA, no eccrine thermoactive sweating in these
animals AFAIK. AFAIK they don't even have eccrines on their bodies!
> >> So let's see what we have now: Hairlessness and more sweat glands to
keep us cooler
> >CA, you're making up your own "facts".
> Hardly.
See above. A factor of 50 doesn't mean anything to you??
> >- Hairlessness: Don't you know that shaving off fur increases body
temperature in open places?
> I have a friend who shaves his beard and close-crops his hair every summer
to cool down. Exposing more skin to wind allows for faster evaporation of
sweat, and thus cools down the body. Anyone whose worn clothing on a hot
day, and then had the chance to "peel" some of it off will appreciate the
loss of "fur".
1) Your friend's beard is underneath his face I presume.
2) When sheep are shaved they risk overheating in summer. We were discussing
hairlessness, remember?
3) Do you only sweat under your beard?
4) What about bedouins? do they like to have the chance to "peel" of their
clothes?
Again: it's a bit more shaded than you seem to think.
> >- Eccrine sweat glands cool off humans & sealions on land.
No answer?
> >> suggests we were dealing with hot weather enough to thrive better by
adapting to it.
> >?? Please don't make up your own "facts".
> Marc, these "made-up" facts are personal experiences of mine or those I've
known. These are repeatable experiments.
Yes, the sheep shaving has been discussed in the scientific literature.
> >> SC fat suggests an annual season where food is difficult to obtain.
> >Again: that's wishful thinking, CA. You are simply assuming what you want
to assume. Facts please. The only primates that have seasonal fat (not SC
but in the tail) are fat-tailed prosimians (estivation). Do you believe our
ancestors (since the Homo-Pan split) spent the summer sleeping in tree
holes??
> SC fat is created during times of plenty, and are depleted through times
of hunger. Ask your doctor, Marc.
So what? Of course it is? Did I deny that?? Just explain to me why humans
are 10 times fatter than chimps.
> It doesn't take Einstein to figure out that this ability helps an organism
make best use of the resources. Bears routinely do this every year, laying
on fat for the winter hibernation when they will burn a considerable amount
of fat keeping warm and alive without eating. Simians lacking this
adaptation obviously have a reasonably reliable year-round supply of food.
They have no need to stock up on food energy for times of crisis.
Yes, so what? Why are African people about 10 times fatter than Japanese
monkeys IYO?
> >> 'Webbing' suggests a development to provide our hands with a superior
grip.
> >Then why do dogs have webbing between the toes? what do dogs have to
grasp?
> Webbing helps them to keep their toes together and pointed in the same
direction, important for long chases.
That's 1 possible explanation. But we agreed "webbing" is not very relevant
here.
> >> Holding breath is a trait we share with all air-breathing animals. No
more indicative of an aquatic existence than it is in any animal.
> >Completely wrong. Human breath hold is far superior to that of dogs or
apes, and superior to that of pigs, inferior to that of Cetacea, can best be
comparred to that of beavers (E.Schagatay 1996 "The human diving response:
effects of temperature and training" Univ.Lund Sweden).
> Which only shows we can be convinced to do something others are unwilling
to do.
No, no, read Schagatay's book. Animals can be trained, remember: see the
title.
> This does not demonstrate an inability in animals, only an unwillingness.
No, no, please not your (wrong) impressions. Facts, CA.
> Unless these scientists were willing to do something as inhuman as to
drwon these poor creatures to see how long they'd hold their breath, I'd
question the results as indicating a problem with motivating the animal in
question.
Refusing to look at the evidence is not very scientific, CA.
> >> None of these adaptations improves our ability to exist in an aquatic
environment. CA
> >As I showed, breath-holding & SC fat are clear adaptations for spending
more time in water.
> Actually, you've shown that SC fat had nothing to do with tropical waters
(no hypothermia
No, no, I've answered this "objection" above.
>), and unless this ability appeared in humans after they left Africa and
entered temperate waters, it has nothing to do with an aquatic existence at
all.
Please, CA, think a bit: "after they left Africa"?? But African people still
live there! Why are African people about 10 times fatter than chimps IYO??
> With breath-holding all you've demonstrated is it is very difficult for
humans to motivate animals to hold their breath.
No, no, see above. It's very obvious to any unbiased observer that humans
dive many times better than chimps. Why IYO?
> >Do you deny that ostriches had flying ancestors?
> I haven't given it any thought, to be honest, and unless there are
compelling reasons to associate ostriches with a flying ancestor I believe
it is possible for the ostrich to derive from a terrestrial bird. Did it
occur to you that flightless birds (ie dinosaurs) are the primitive version
of birds? Where do you draw the line between a feathered, flightless
dinosaur and a feathered, flightless bird? Back at the split there was very
little difference at all.
So you believe that they have wings for nothing? or for running faster over
the savanna? just as you believe that humans dive many times better than
chimps for no reason? or for running faster perhaps??
> >Why don't you give your own explanation why humans differ from chimps?
> I've been doing that, Marc. Read some of my other articles.
Where can I find them? Can't you give them here in a nutshell?
> >Of course ostriches are adapted to the lifestyle they live today, does
that prevent them from having flying ancestors?
> No, it doesn't. And you make a great argument there too. Just as an
ostrich can have a flying ancestor, a Human with sc fat and furlessness can
have an ancestor that had neither. CA
No: humans are 10 times fatter than chimps. Why IYO? And they have much less
fur. Why IOY? Why can they dive & chimps can't? What is unlikely IYO in our
view than early Homo (begin Pleistocene) dispersed over southern Eurasia
along the coasts of the Mediterranean & Indian Ocean?
Michael Clark
>
> "AC" <sp...@nospam.com.invalid> wrote in message
> news:slrnb0svm...@ts1.alberni.net...
>
> > Namely, the fossil record.
[the usual]
OK, so since his plonking, the only place I see Marco is over on T.O.
Perhaps if I retrieve his sorry hide from the ol' bit bucket...
> Many leading paleoanthropologists are wiser & are
> more open-minded, eg, http://allserv.rug.ac.be/~mvaneech/outthere.htm
Nowhere have I stated, either in print or on a public platform, or on the
media, that I support the AAH!
[..]
With best wishes,
Yours sincerely,
(Professor Emeritus) Phillip V. Tobias
> Marc Verhaegen
> http://www.onelist.com/community/AAT
> http://allserv.rug.ac.be/~mvaneech/Verhaegen.html
-------------
Michael Clark
bit...@spammer.com
Hey Marco. Got that A'pith menu yet?
ejudy
> "Marc Verhaegen" wrote:
> >"Curious Amateur" <no_...@home.guv> wrote :
Now even i can appreciate this,CA.
We should keep this post _bookmarked_
somewhere as an elegant answer to that old
AAT redundant inquiry quandary.
I will recommend it to Jois as it was her
time saving efficiency idea.
I think you have done a spiffy little piece of work here, CA.
Bravo.
[...............]
I especially like the clear logic in this passage:
[...........}
This too:
>
> >Of course
> >ostriches are adapted to the lifestyle they live today, does that prevent
> >them from having flying ancestors?
>
> No, it doesn't.
>
> And you make a great argument there too. Just as an ostrich can have a flying
> ancestor, a Human with sc fat and furlessness can have an ancestor that had
> neither.
>
> CA
~ej~
...;-).... (no teeth see hahaha!)
Curious Amateur
>no_...@home.guv (Curious Amateur) wrote:
>> "Marc Verhaegen" wrote:
>> >"Curious Amateur" <no_...@home.guv> wrote :
>
>Now even i can appreciate this,CA.
>We should keep this post _bookmarked_
>somewhere as an elegant answer to that old
>AAT redundant inquiry quandary.
>I will recommend it to Jois as it was her
>time saving efficiency idea.
>I think you have done a spiffy little piece of work here, CA.
>Bravo.
Thank you :-)
snip
>
>~ej~
>....;-).... (no teeth see hahaha!)
:-)
CA
firstjois
"Michael Clark" <bit...@spammer.com> wrote in message
news:v0u6d0p...@corp.supernews.com...
: > Many leading paleoanthropologists are wiser & are
: > more open-minded, eg, http://allserv.rug.ac.be/~mvaneech/outthere.htm
:
: Nowhere have I stated, either in print or on a public platform, or on the
: media, that I support the AAH!
:
: [..]
:
: With best wishes,
:
: Yours sincerely,
:
: (Professor Emeritus) Phillip V. Tobias
:
What a shame that we haven't got some kind of photo gallery where we could
hang this one on the wall. Maybe enlarged, red border, lace edges,
seabreeze color frame. Put Marco's post beside it, slightly lower and much
smaller, of course, and dripping water naturally.
Jois
Marc Verhaegen
"firstjois" <firstjo...@hotmail.com> wrote in message
news:DP6dnc8qI-A...@comcast.com...
> : > Many leading paleoanthropologists are wiser & are more open-minded,
eg, http://allserv.rug.ac.be/~mvaneech/outthere.htm
> What a shame that we haven't got some kind of photo gallery where we could
hang this one on the wall. Maybe enlarged, red border, lace edges,
seabreeze color frame. Put Marco's post beside it, slightly lower and much
smaller, of course, and dripping water naturally. Jois
The usual blabla of the savanna believers. No contents.
Prof.Tobias on the savanna nonsense:
"Humans are not savannah-adapted animals - In rejecting the SH, I was moved
primarily by the evidence unearthed in South Africa and East Africa.
Meanwhile, Elaine Morgan had been piecing together a number of other
arguments against the SH, based on some anatomical, biochemical and
physiological data of modern humans, much of which was collected by
Belgium's Dr Marc Verhaegen, which contrast sharply with the traits in
present-day animals that are truly adapted to savannah life. As
examples, modern humans lack sun-reflecting fur and are virtually hairless.
The cooling system in our skin is quite unfit for hot, dry, exposed
environments: we have numerous sweat glands and we waste water and sodium -
not very suitable for life on the savannah. Our ability to concentrate our
urine is poor and too low and if ever our earliest ancestors were savannah
dwellers, we must have been the worst, the most profligate urinators there.
Adapted savannah-dwellers need to drink more water at a time, but most
humans are not able to drink much at a time. The quantity of our
subcutaneous fat, which would insulate us against heat loss, is never found
in truly savannah-adapted animals. In our bodily functions, chemistry
and microscopical anatomy, we should be hopeless as savannah-dwellers. So
Marc Verhaegen and Elaine Morgan, in her remarkable book, The Scars of
Evolution, came to the same conclusion that we had reached from quite
different lines of evidence: the old Savannah Hypothesis was not tenable.
All former savannah supporters must recant and this I did in London. It
was an exciting moment - living through a change of paradigm. Max
Planck, the German physicist and Nobel laureate, once wrote these words on
the replacement of an outworn paradigm: "A new scientific truth does not
triumph by convincing its opponents and making them see the light, but
rather because its opponents eventually die, and a new generation grows that
is familiar with it." That must be one of the masterpieces of cynicism on
the scientific process. Paradigm changes, I like to think, flow
overwhelmingly from new evidence and, where the evidence is sound and even
irresistible, they should be embraced just as lief by the old as by the
young. It was three weeks after my 71th birthday and I went on to declare,
"A change of paradigm shakes us up; it rejuvenates us; and, this above all,
it prevents mental fossilisation - and that is good for all of us."
Michael Clark
>
> "firstjois" <firstjo...@hotmail.com> wrote in message
> news:DP6dnc8qI-A...@comcast.com...
>
> > : > Many leading paleoanthropologists are wiser & are more open-minded,
> eg, http://allserv.rug.ac.be/~mvaneech/outthere.htm
>
> > What a shame that we haven't got some kind of photo gallery where we could
> hang this one on the wall. Maybe enlarged, red border, lace edges,
> seabreeze color frame. Put Marco's post beside it, slightly lower and much
> smaller, of course, and dripping water naturally. Jois
>
> The usual blabla of the savanna believers. No contents.
>
> Prof.Tobias on the savanna nonsense:
Nowhere have I stated, either in print or on a public platform, or on the
media, that I support the AAH!
[..]
With best wishes,
Yours sincerely,
(Professor Emeritus) Phillip V. Tobias
[macro]
> Marc Verhaegen
> http://www.onelist.com/community/AAT
> http://allserv.rug.ac.be/~mvaneech/Verhaegen.html
firstjois
[snip]
Hi MB,
+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+
Nowhere have I stated, either in print or on a public platform, or on the
media, that I support the AAH!
[..]
With best wishes,
Yours sincerely,
(Professor Emeritus) Phillip V. Tobias
*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+
I did read something that reminded me of the AAR group this past week:
On the first day of puppy
The little dear made wee
On the carpeting in the hallway
On the second day of puppy
The little dear made wee
Underneath our tree
On the carpeting in the hallway
On the third day of puppy
The little dear made wee
Right in Marco's shoe
Underneath our tree
On the carpeting in the hallway
Well, I guess you can figure out what the rest would be about, eh?
Jois
+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+
Nowhere have I stated, either in print or on a public platform, or on the
media, that I support the AAH!
[..]
With best wishes,
Yours sincerely,
(Professor Emeritus) Phillip V. Tobias
*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+
Dr. Tobias, I bet you are a lovely person! Happy New Year!
Jois
Bob Keeter
bit...@spammer.com wrote on 12/29/02 3:47 PM:
Very interesting! ;-)
Marc,
Here in the States we have a saying "Back up 15 and punt!" The basic meaning
is that according to the rules of the game, you have to kick the ball to the
opposing team's offensive team and trot your offensive players off of the
field. If Im reading this thread correctly, you cite a persons's "wisdom"
in support of your theory and that person disclaims the concept, those
"quoted" words and for the record, ever even having said or written them.
This is not good. Maybe you accidentally mis-interpreted them? Maybe
someone else mis-quoted them to you! Maybe its just plain confusion! Maybe,
just maybe, its also time to consider an apology and a retraction?
IOW, "Back up 15 and punt!" 8-)
Regards
bk
AC
The Church of the Aquatic Ape, even when fully submerged in the waters of
its own lack of evidence, never retracts. I'm sure Mr. Verhaegen will
simply repeat his previous statement.
--
AC
Bob Keeter
sp...@nospam.com.invalid wrote on 12/30/02 3:02 AM:
Snippage. . . .
>>
>> Very interesting! ;-)
>>
>> Marc,
>>
>> Here in the States we have a saying "Back up 15 and punt!" The basic meaning
>> is that according to the rules of the game, you have to kick the ball to the
>> opposing team's offensive team and trot your offensive players off of the
>> field. If Im reading this thread correctly, you cite a persons's "wisdom"
>> in support of your theory and that person disclaims the concept, those
>> "quoted" words and for the record, ever even having said or written them.
>> This is not good. Maybe you accidentally mis-interpreted them? Maybe
>> someone else mis-quoted them to you! Maybe its just plain confusion! Maybe,
>> just maybe, its also time to consider an apology and a retraction?
>>
>> IOW, "Back up 15 and punt!" 8-)
>
> The Church of the Aquatic Ape, even when fully submerged in the waters of
> its own lack of evidence, never retracts. I'm sure Mr. Verhaegen will
> simply repeat his previous statement.
And thats one possibility. The other is that Marc siezed the opportunity to
gain a certain credibility and respectability. One of those "choice"
issues, . . . and you just never KNOW what choices might be made.
Regards
bk
Michael Clark
news:BA351CB0.23105%rke...@earthlink.net...
> in article v0u6d0p...@corp.supernews.com, Michael Clark at
> bit...@spammer.com wrote on 12/29/02 3:47 PM:
[Tobias quote]
> Very interesting! ;-)
>
> Marc,
>
> Here in the States we have a saying "Back up 15 and punt!" The basic meaning
> is that according to the rules of the game, you have to kick the ball to the
> opposing team's offensive team and trot your offensive players off of the
> field. If Im reading this thread correctly, you cite a persons's "wisdom"
> in support of your theory and that person disclaims the concept, those
> "quoted" words and for the record, ever even having said or written them.
> This is not good. Maybe you accidentally mis-interpreted them? Maybe
> someone else mis-quoted them to you! Maybe its just plain confusion! Maybe,
> just maybe, its also time to consider an apology and a retraction?
>
> IOW, "Back up 15 and punt!" 8-)
>
> Regards
> bk
Oh, I don't think you'll see Marco retracting anything anytime soon.
What Tobias has said (in that macro that Marco is so fond of posting)
is that he has "finally" had a parting of ways with the "savanna theory".
That's all very well and good. What our Belgian Bottlewasher fails to
grasp is that this does not equate to ~support~ for the AAR. It really
is rather simple (and Tobias has said so).
Bipedalism arose in the trees. After a certain threshold in body size
is reached, it becomes most efficient for a large-bodied, arboreal primate
to either move beneath branches or on ~top~ of them (bipedally!).
So beating up on antelope chasers on the short grass prairie, or LCA's
bent on standing up to escape the mid-day sun is literally BARKING
UP THE WRONG TREE. (lightbulb! --ding,ding!)
OK, gentle readers, let's all synchronize watches so we can accurately
measure how long it takes the ~master of the macro~ to "get it".
<tick-tock, tick-tock, tick-tock>
Lorenzo L. Love
If he was the slightest bit interested in credibility and
respectability, he wouldn't be daily making a fool of himself. It's
characteristic of his deep psychosis that he believes the stuff he makes
up.
Lorenzo L. Love
http://home.thegrid.net/~lllove
Main Entry: psy·cho·sis
Pronunciation: sI-'kO-s&s
Function: noun
Inflected Form(s): plural psy·cho·ses /-"sEz/
Etymology: New Latin
Date: 1847
: fundamental mental derangement (as schizophrenia) characterized by
defective or lost contact with reality
© 1999 by Merriam-Webster, Incorporated
Bob Keeter
lll...@thegrid.net wrote on 12/30/02 3:44 AM:
OK now! Watchit or we start critically talking about those darned "kitty
cats" and pretend that we did not recognized the parody! 8-) LOL!
Seriously, sometimes that old "reductio ad absurdium" approach just might
force a change of feathers. Here we have a direct quote that is either a
forgery, an error. The perpetrator needs to come clean, else we will all be
forced to simply chalk it up as a forgery and he drifts right off the left
hand side of the scale.
Getting caught in a mistake is not exactly a unique circumstance, failing to
own up to that mistake, or come clean on the forgery, well, that is
different. That would be one of those things that even I, arch-Libertarian
that some claim, harp on as having no place in science; not amongst the
people that we happen to agree with nor then ones that we disagree with.
So. . . . . . . Lets see how Marc chooses to address it. It could be a
mistaken quote, and a simple error in interpretation on his part, and he is
sorry for it; OR it is a forgery, intended as such, and continued as such,
and he is unrepentant for the forgery. First case, well, we have all erred.
Second case, its just a matter of truthfullness, honor, personal integrity
and scientific professionalism. (Pretty big "just" wouldnt you say? ;-) )
Professional scientists dont need and cannot tolerate forgery or lies, and
Ive even discussed that at LENGTH with some other members of this group, so
its not just an AAH issue as far as Im concerned!
So. . . we will see.
Regards
bk
Michael Clark
> in article 3E0FC0D4...@thegrid.net, Lorenzo L. Love at
> lll...@thegrid.net wrote on 12/30/02 3:44 AM:
>
No, Bob. The issue is not whether or if Marco is lying --the "Out there" article
is real enough. The issue is what sort of "spin" he puts on it. Watch your mailbox
and judge for yourself.
> Regards
> bk
>
Jim McGinn
> Bipedalism arose in the trees. After a certain threshold in body size
> is reached, it becomes most efficient for a large-bodied, arboreal primate
> to either move beneath branches or on ~top~ of them (bipedally!).
It is true that bipedalism arose in a species that occupied trees.
But it's pretty whacko to say that bipedalism arose in trees. And who
knows where you're getting this "threshold," BS.
Michael Clark
news:ac6a5059.02122...@posting.google.com...
If you're having difficulty following this, Jimmy, it isn't because you
are simply looking for an argument (which is certainly true), it is
because you don't know ~anything~ about current PA. No surprise!
Now run along and go play in the traffic.
Get run out of SBE?
---------
Michael Clark
bit...@spammer.com
"You don't build hypotheses on the basis of unsupported conjecture."
--Jim McGinn
Philip Deitiker
news:DP6dnc8qI-A...@comcast.com:
>: Nowhere have I stated, either in print or on a public platform, or on
>: the media, that I support the AAH!
>: With best wishes,
>: Yours sincerely,
>: (Professor Emeritus) Phillip V. Tobias
> What a shame that we haven't got some kind of photo gallery where we
> could hang this one on the wall. Maybe enlarged, red border, lace
> edges, seabreeze color frame. Put Marco's post beside it, slightly
> lower and much smaller, of course, and dripping water naturally.
Lol. with clowns, elves, and grimlins decorating its frame and the
inscription of some famous limey on the futility of a man's folly snaking
almost invisibly amoungst the characters of the frame.
Please folks however watch the NG line in followups:
"talk.origins,sci.anthropology,sci.anthropology.paleo"
we do not want to attract any more black waterfowl than we aptly deserve.
Bob Keeter
bit...@spammer.com wrote on 12/30/02 4:33 AM:
Snippage. . . . .
> No, Bob. The issue is not whether or if Marco is lying --the "Out there"
> article is real enough. The issue is what sort of "spin" he puts on it.
> Watch your mailbox and judge for yourself.
>
>
Guess I have a problem with the distinction some try to make between
"spinning" and "lying". Way too fine and cultured of a difference for my
feeble ole simpleton mind I guess. A thing either "IS", or it "ISN'T"! If I
were to try to maintain that an "ISN'T" is an "IS" ( Egads, doesnt that
sound downright "Clintonian"? ;-) ), no matter what 'English' I put on the
pitch, its still a lie. OOOOhhhh did I make a little double ententre there!
Just in case you werent watching of course! ;-)
Sorry, guess I just never graduated to "Technicolor" or even "gray scale" in
some things! Intellectual honesty and personal integrity just seem such
nice, well-behaved single-digit binary processes, that anyone worth of the
title "professional" or even aspiring to "respectable" have to be very
careful to observe since it underpins the "trust" others are prone to give!
But then thats the "problem" some people never get over! No amount of
affluence, position, education or reputation can truely insulate a person
from having to "tell the truth" at some point! (i.e. Nixon, Hart, Clinton;
on that last one, certainly one of these days!)
8-)
But as you said, we will all see, and what we see is definitely up to Mr.
Marc!
Have a good one, and the best of the New Year to you and yours!
Regards
bk
Philip Deitiker
news:3E0FC0D4...@thegrid.net:
> If he was the slightest bit interested in credibility and
> respectability, he wouldn't be daily making a fool of himself. It's
> characteristic of his deep psychosis that he believes the stuff he
> makes up.
He did leave the group for a time, but returned and shortly thereafter #d
and J@b followed, you notice he has been xposting between TO and sap.
His psychosis, as previously defined, may be inadequate for the new task it
has to serve, as he might have gotten a few pointers from some more rather
skilled and troll worthy loons. lol..
At some point, when fruit loops get big enough, they finally become a donut
which may be why we have sayings like
'go take a flying leap at a rolling donut'
Ah, but ladies in gentlemen this all escapes me, because somehow the AAT
has not registered with my kill filter and thus I need to do a little 'add
to score file'.
Score:: -9999
Subject: aat
Bob Keeter
Since this posting I have not seen a comprehensive reply.
Perhaps time to "punt" and retain some respectability or. . . . not.
Regards
bk
in article v0u6d0p...@corp.supernews.com, Michael Clark at
bit...@spammer.com wrote on 12/29/02 3:47 PM:
Marc Verhaegen
> Got that A'pith menu yet?
Our tooth microwear studies indicate that A. afarensis molar enamel has a
glossy polished surface that is typical of the molars of capybaras
Hydrochoerus hydrochaeris and mountain-beavers Aplodontia rufa24. Both these
semi-aquatic rodents feed mainly on riverside herbs, grasses and the bark of
young trees. The microwear of Australopithecus boisei displays more pits,
wide parallel striations and deep-recessed occlusal dentine features when
compared to A. afarensis25,26, resembling that of beavers Castor fiber,
which feed on riverine herbs, roots of water-lilies, bark and woody plants.
Apparently, an early australopith diet of fruits (larger front-teeth) and
swamp herbs (polishing) was supplemented with woody plants in the robust
australopiths (more wear). Walker's suggestion that A. boisei were
bulk-eaters of "small, hard fruits with casings, pulp, seeds and all"27
could explain the deep-recessed dentine, but not the heavily polished enamel
that is typical of marsh-plant feeders24,25.
These microwear data are consistent with two studies on South-African
australopiths28,29. Sillen provides three possibilities for low
strontium:calcium ratios in A. robustus: partial carnivory; eating leaves
and shoots of forbs and woody plants; and eating food derived from
well-drained streamside soils28. Sponheimer and Lee-Thorp state that A.
africanus "ate not only fruits and leaves but also large quantities of
carbon-13-enriched foods such as grasses and sedges or animals that ate
these plants, or both"29. However, regular consumption of savannah grasses
is incompatible with the polished, rounded microwear24,29 and predominant
meat eating is unlikely in view of the blunt molars27. More probable is a
diet of sedges and other marshland plants supplemented with fruits and
animals (e.g. tools attributed to A. robustus now suggest termite-eating30).
Independent lines of evidence thus suggest that different australopith
species regularly waded for shallow-water plants, possibly like lowland
gorillas do today15, only much more frequently. Papyrus or reed sedges were
abundant in australopith environments (Table 2) and are part of the diet of
extant hominids. Gorillas eat bamboo shoots and stalks, as well as swamp
herbs and sedges (Table 1); all hominids eat cane; bipedally wading
chimpanzees and humans collect water-lilies; and rice growing in shallow
water and other cereals are staple foods for humans.
Marc Verhaegen
> Nowhere have I stated, either in print or on a public platform, or on the
media, that I support the AAH!
Humans are not savannah-adapted animals - In rejecting the SH, I was moved
Marc Verhaegen
I have not seen a comprehensive reply of the savanna believers to what
Tobias said http://allserv.rug.ac.be/~mvaneech/outthere.htm
Humans are not savannah-adapted animals
Marc Verhaegen
>If Im reading this thread correctly, you cite a persons's "wisdom" in
support of your theory
Apparently you can't read.
>and that person disclaims the concept
Apparently he did not, he said: Nowhere have I stated, either in print or on
a public platform, or on the media, that I support the AAH!
>, those "quoted" words and for the record, ever even having said or written
them.
Keeter, I've met prof.Tobias a few times, and I know very well what he
thinks of my theory and of the SH.
http://allserv.rug.ac.be/~mvaneech/outthere.htm
Humans are not savannah-adapted animals - In rejecting the SH, I was moved
I hope you know there's a difference between saying "SH is wrong" & "SH is
not necessarily correct"
Marc Verhaegen
>
> "firstjois" <firstjo...@hotmail.com> wrote in message
> news:kaKdnZrS5dY...@comcast.com...
>
> > Nowhere have I stated, either in print or on a public platform, or on
the
> media, that I support the AAH!
Sorry I forgot the URL
http://allserv.rug.ac.be/~mvaneech/outthere.htm
Bob Keeter
fa20...@skynet.be wrote on 12/30/02 9:05 PM:
Snippage. . . .. .
>
> I hope you know there's a difference between saying "SH is wrong" & "SH is
> not necessarily correct"
>
Just as I hope that advocating a clear and logical consideration (and
possibly refutation of the AAH) is NOT the same as supporting the AAH! I,
or Prof. Tobias, or ANYONE, can say that your concept deserves an honest,
unemotional assessment without advocating its truth or credibility.
In your particular case, have you EVER said that Prof. Tobias SUPPORTED the
AAH or have you always held that he supported the honest evaluation of the
concept? AND if an honest evaluation were provide (as CA tried to provide
quite nicely on this forum recently) would you be able to unemotionally
accept the "findings" or would it be pointless?
And yea, I can sorta read a little bit. . . . . 8-)
Regards
bk
Marc Verhaegen
> Just as I hope that advocating a clear and logical consideration (and
possibly refutation of the AAH) is NOT the same as supporting the AAH!
Sigh. For the 100th time, idiot, nobody ever said that. For Tobias' opinion
on the matter just read his own paper
http://allserv.rug.ac.be/~mvaneech/outthere.htm Did he say there he
supports "AAH" (whatever that may mean)??
Marc Verhaegen
"Curious Amateur" <no_...@home.guv> wrote in message
news:IyyP9.2$rr1....@news20.bellglobal.com...
> First, I'll point out you've snipped a lot from my previous article, Marc.
CA, I'm going to snip everything. Sorry, I think you're a nice guy & I'm
sure you mean what you're saying, but there are more pleasant things to do
than repeating everything that has been discussed here many times. I realise
you're unconvinceable (because too biased IMO) - why should I do the effort?
(Please inform on the things you're discussing: you hadn't even heard of
Kenyanthropus! If you really want to understand what I'm saying on apiths
(has nothing to do with AAT) please read my Hum.Evolution papers
http://allserv.rug.ac.be/~mvaneech/Fil/Verhaegen_Human_Evolution.html )
Best - until I have more time perhaps.
Marc
Michael Clark
>
> "Michael Clark" <bit...@spammer.com> wrote in message
> news:v0v90vr...@corp.supernews.com...
>
> > Got that A'pith menu yet?
Here is another of Marco's Macros (tm). Again (!), here are the questions that
inevitably crop up.
> Our tooth microwear studies indicate that A. afarensis molar enamel has a
> glossy polished surface that is typical of the molars of capybaras
> Hydrochoerus hydrochaeris and mountain-beavers Aplodontia rufa24. Both these
> semi-aquatic rodents feed mainly on riverside herbs, grasses and the bark of
> young trees. The microwear of Australopithecus boisei displays more pits,
> wide parallel striations and deep-recessed occlusal dentine features when
> compared to A. afarensis25,26, resembling that of beavers Castor fiber,
> which feed on riverine herbs, roots of water-lilies, bark and woody plants.
> Apparently, an early australopith diet of fruits (larger front-teeth) and
> swamp herbs (polishing) was supplemented with woody plants in the robust
> australopiths (more wear). Walker's suggestion that A. boisei were
> bulk-eaters of "small, hard fruits with casings, pulp, seeds and all"27
> could explain the deep-recessed dentine, but not the heavily polished enamel
> that is typical of marsh-plant feeders24,25.
Is the "polish" (a highly subjective term) seen "ONLY" in capybaras?
Answer the question. Don't tell me that it comes exclusively from "marsh plants"
when you KNOW that it comes from a variety of sources. DON'T LIE!
> These microwear data are consistent with two studies on South-African
> australopiths28,29.
Since these are qualitative assessments, they would be "consistent" with
darn near anything. Note that neither of these sources ~support~ your story
that A'piths were exclusive eaters of "marsh plants"
> Sillen provides three possibilities for low
> strontium:calcium ratios in A. robustus: partial carnivory; eating leaves
> and shoots of forbs and woody plants; and eating food derived from
> well-drained streamside soils28. Sponheimer and Lee-Thorp state that A.
> africanus "ate not only fruits and leaves but also large quantities of
> carbon-13-enriched foods such as grasses and sedges or animals that ate
> these plants, or both"29. However, regular consumption of savannah grasses
> is incompatible with the polished, rounded microwear24,29
WHY?! What about grass SEEDS? Where are opal phytoliths found?
You need to provide an answer to ~each~ of these questions --note the
~question marks~ . What the hell is wrong with "savanna grasses", Marco?
Is this another of your desperate attempt to separate a'piths from the
savanna? Hmmm?
> and predominant
> meat eating is unlikely in view of the blunt molars27.
Do you eat meat, Marco? Are your molars "blunt"? What does that
tell you --if anything....?
> More probable is a
> diet of sedges and other marshland plants supplemented with fruits and
> animals (e.g. tools attributed to A. robustus now suggest termite-eating30).
Why "marshland plants" ? Why not "savanna grasses" (seeds)?
> Independent lines of evidence thus suggest that different australopith
> species regularly waded for shallow-water plants,
WHAT evidence? You familiarize yourself with the term taphonomy yet?
How long have you had to work it out? 10 years? 20?
> possibly like lowland
> gorillas do today15, only much more frequently.
Really? Where's your evidence for the "frequency" of wading for shallow
water plants?
> Papyrus or reed sedges were
> abundant in australopith environments (Table 2) and are part of the diet of
> extant hominids.
So are grass seeds.
> Gorillas eat bamboo shoots and stalks, as well as swamp
> herbs and sedges (Table 1); all hominids eat cane; bipedally wading
> chimpanzees and humans collect water-lilies; and rice growing in shallow
> water and other cereals are staple foods for humans.
This is not evidence in support of your contention that a'piths ate marshland
plants. This is merely handwaving and empty verbiage. Intro students get
their butts chewed for doing just this sort of "research".
-----------
Michael Clark
bit...@spammer.com
Hey Marco. Got that A'pith menu yet?
Michael Clark
>
> "Bob Keeter" <rke...@earthlink.net> wrote in message
> news:BA35F74D.2328C%rke...@earthlink.net...
>
Nowhere have I stated, either in print or on a public platform, or on the
media, that I support the AAH!
[..]
With best wishes,
Yours sincerely,
(Professor Emeritus) Phillip V. Tobias
------------
Michael Clark
No, STUPID, this is what he said:
Nowhere have I stated, either in print or on a public platform, or on the
media, that I support the AAH!
[..]
With best wishes,
Yours sincerely,
(Professor Emeritus) Phillip V. Tobias
Michael Clark
>
> "Bob Keeter" <rke...@earthlink.net> wrote in message
> news:BA351CB0.23105%rke...@earthlink.net...
>
>
> >If Im reading this thread correctly, you cite a persons's "wisdom" in
> support of your theory
>
> Apparently you can't read.
[macro]
Nowhere have I stated, either in print or on a public platform, or on the
media, that I support the AAH!
[..]
With best wishes,
Yours sincerely,
(Professor Emeritus) Phillip V. Tobias
> I hope you know there's a difference between saying "SH is wrong" & "SH is
> not necessarily correct"
And we should take our reading comprehension clues from you?
Curious Amateur
Well, I'm disappointed, Marc.
No, I won't be wasting more time on you. I did that in my previous article and
you've seen fit to discard it as "too biased".
It is too obvious you do not practice "good science", Marc. You discard facts
you do not like, regardless of how true they are.
Marc, in North America we have an epidemic of obesity. A lot of scientific
work has gone into understanding the mechanisms that affect SC fat. SC fat is
created by using fewer calories than are taken in. SC fat is burned by using
more calories than are taken in. It is well understood here that it is an
adaptive trait to deal with 'feast or famine' scenarios (seasonal variations
in the availability of food).
You claim this is wishful thinking, as if the study and experience of
biologists, dieticians and weight-watchers can be dismissed with a phrase.
That is the true wishful thinking, Marc, to ignore proven facts in favour of a
theory you cannot prove.
Your claim that fur cools the skin, and that the removal of fur heats the
skin, is another example of wishful thinking. Just ask a Husky if he's
freezing in winter with all that fur. Ask a polar bear. And then ask dogs why
they shed fur in the summer. They'll tell you it is to keep cool. You claim
some animals are hairless which are obviously not hairless (wild dogs and wart
hogs).
What faith can we place in that kind of 'research'
You claim sirenia and cetacea support your hairless=aquatic argument, while
failing to note that pinnipeds do not support that argument. You fail to note
that all three groups are far more advanced than humans when it comes to
aquatic adaptations, and that an aquatic existence is not linked to fur in any
way (pinnipeds did not need to lose fur to become as aquatic as they are, far
more aquatic than humans).
You claim hypothermia is not a problem in the tropics, yet cannot explain why
we would need a layer of SC fat to keep us warm while we're wading in those
same warm tropical waters.
And when pinned down about these discrepancies between fact and theory, you
decide I am too biased to deserve any more of your time, while
spending that time reposting the same quote from Tobias four or five times in
a row.
I don't think I need to waste any more time on AAT, do I Marc? You practice
neither "good science" nor "good education".
Erika mentioned that Jois keeps a list of responses to your 'macros'. Since my
arguments seem to have stumped you, I recommend they be included in this
archive for future use. If they can stump you once, Marc, they'll stump you
every time till you can explain yourself more clearly.
CA
Marc Verhaegen
> > Our tooth microwear studies indicate that A. afarensis molar enamel has
a glossy polished surface that is typical of the molars of capybaras
Hydrochoerus hydrochaeris and mountain-beavers Aplodontia rufa24. Both these
semi-aquatic rodents feed mainly on riverside herbs, grasses and the bark of
young trees. The microwear of Australopithecus boisei displays more pits,
wide parallel striations and deep-recessed occlusal dentine features when
compared to A. afarensis25,26, resembling that of beavers Castor fiber,
which feed on riverine herbs, roots of water-lilies, bark and woody plants.
Apparently, an early australopith diet of fruits (larger front-teeth) and
swamp herbs (polishing) was supplemented with woody plants in the robust
australopiths (more wear). Walker's suggestion that A. boisei were
bulk-eaters of "small, hard fruits with casings, pulp, seeds and all"27
could explain the deep-recessed dentine, but not the heavily polished enamel
that is typical of marsh-plant feeders24,25.
> Is the "polish" (a highly subjective term) seen "ONLY" in capybaras?
Finally willing to discuss the matter?
:-)
If you had really read the above you would have known my answer:
1) Didn't you see the word "mountain beavers"??
2) "Typical" is the word Puech used. He's not aware of exceptions AFAIK.
3) The glossy aspect of the surface comes from polishing by the wet plants
of course.
> Answer the question.
I have. Why wouldn't I answer that question??
> Don't tell me that it comes exclusively from "marsh plants" when you KNOW
that it comes from a variety of sources. DON'T LIE!
The liar tells me not to lie!? Man, you're sick.
And don't SHOUT.
> > These microwear data are consistent with two studies on South-African
australopiths28,29.
> Since these are qualitative assessments, they would be "consistent" with
darn near anything. Note that neither of these sources ~support~ your story
that A'piths were exclusive eaters of "marsh plants"
LIAR. Ourt story is NOT that apiths were exclusive marsh plant eaters. Had
you read the relevant literature you would have known.
> > Sillen provides three possibilities for low strontium:calcium ratios in
A. robustus: partial carnivory; eating leaves and shoots of forbs and woody
plants; and eating food derived from well-drained streamside soils28.
Sponheimer and Lee-Thorp state that A.africanus "ate not only fruits and
leaves but also large quantities of carbon-13-enriched foods such as grasses
and sedges or animals that ate these plants, or both"29. However, regular
consumption of savannah grasses is incompatible with the polished, rounded
microwear24,29
> WHY?! What about grass SEEDS?
INCOMPATIBLE. if you had read the relevant literature you would have know.
Seeds give a very different microwear.
> Where are opal phytoliths found? You need to provide an answer to ~each~
of these questions --note the ~question marks~ . What the hell is wrong
with "savanna grasses", Marco?
You're a real FOOL. An uninformed idiot with a big MOUTH. Apparently you
haven't even read Sponheimer&L-T's paper!?
EVERYTHING is wrong with savanna grasses: they produce a completely
different microwear: not glossy, but fabric-like microwear. You would have
known that if you had informed a little bit:
"Dental studies suggest that whereas gracile australopithecines preferred
softer fruits and vegetables, the robusts' diet included harder food items
(e.g. Robinson, 1954; Du Brul, 1977; Walker, 1981; Puech, 1992; Lee-Thorp et
al., 1994). Estimates of robust australopithecine bite force suggest
'low-energy food that had to be processed in great quantities' and food
objects 'hard and round in shape' (Demes & Creel, 1988). Du Brul (1977)
noticed dental parallelisms between the robust australopithecines and the
bamboo-eating giant panda Ailuropoda melanoleuca (broad, high and heavy
cheekbones, reduced prognathism and front teeth, broad back teeth, premolar
molarisation), as opposed to gracile australopithecines, respectively
non-panda bears. Papyrus and reed were present in the paleo-environment
of the later australopithecines (e.g. Olduvai, Chesowanja, Kromdraai), and
Cyperaceae and Gramineae are part of the diet of living African hominoids.
Gorillas eat sedges and bamboo shoots and stalks, gorillas and chimpanzees
eat cane, chimps and humans eat water lilies, and rice and other cereals are
staple food for humans. Supplementing their diet with parts of grasslike
plants might have been enabled the robusts to bridge the dry season, when
fruits and soft vegetables were scarce. Studies of dental enamel
microwear provide other details. In the early australopithecines of
Garusi-Laetoli and Hadar (A. afarensis 4-3 Myr BP), the cheekteeth enamel
has a polished surface and the microwear looks like that of the capybara
Hydrochoerus hydrochaeris and that of the mountain beaver Aplodontia rufa
(Puech et al., 1986). These animals are semi-aquatic rodents that feed
mainly on sappy marsh and riverside herbs, grasses and bark of young trees.
It has recently become clear that Western lowland gorillas G. g. gorilla
spend some time eating aquatic herbaceous vegetation (AHV) like
Hydrocharitaceae herbs and Cyperaceae sedges (Doran & McNeilage, 1997).
Comparisons of molar enamel in South African fossils show that A. robustus
ate substantially more hard food items than A. africanus (Grine & Kay,
1988). Incisal microwear suggests that A. robustus may have ingested foods
that required less extensive incisal preparation than the foods consumed by
A. africanus, such as fruits (Ungar & Grine, 1991), and 'incisors need not
be employed in the manipulation of hard objects' (Ungar & Grine, 1989).
The enamel of the East African robusts (Olduvai and Peninj) displays more
pits, wide parallel striations and deep recessed dentine, resembling that of
the beaver Castor fiber, that eats riverine and riverside herbs, roots of
water lilies, bark and woody plants in a temperate climate. 'Many food
plants growing in marsh land and indeed many grasses, have high
concentrations of siliceous particles known as opal phytoliths. The
consumption of such foods produces a great deal of wear, and the enamel and
dentine have a blunted appearance. Ancient Egyptians ate papyrus shoots
(Puech et al., 1983b) and we suppose that [O.H.16] did the same with swamp
margin plants' (Puech, 1992). Whereas the East African robusts seem to have
had aquatic plants and papyrus shoots in their diet and ate more woody
plants than the earlier australopithecines, habilis O.H.16 apparently
supplemented the AHV of the earlier australopithecines with acid fruits
(Puech, 1984). In the habilis cheekteeth, the margins of the striae have
been polished and slightly etched, resembling the microwear of the coypu
Myocastor coypus. This rodent feeds on reed, sedges, marsh plants, fruits
and molluscs in river and lake margins. It thus seems that an early
australopithecine diet of fruits (larger front teeth) and AHV (polishing)
was supplemented with unripe fruits (acid etching) in habilis, and with
woody plants in the robusts (more wear). The suggestion of Walker (1981)
that A. boisei KNM-ER 406 and 729 were bulk-eaters of whole fruits, 'small,
hard fruits with casings, pulp, seeds and all', could explain the deep
recessed occlusal dentine, but not the glossy appearance of heavily polished
enamel, which is more typical for marsh plant feeders. In terrestrial
grazers such as sheep, tooth wear is faster, with a different gradient and
fabric-like grooves."
> Is this another of your desperate attempt to separate a'piths from the
savanna? Hmmm?
SILLY IDIOT. You are completely INCAPABLE of giving 1 SINGLE argument in
favour of your IDIOTIC savanna nonsense, and you speak of desperate??
:-D
> > and predominant meat eating is unlikely in view of the blunt molars27.
> Do you eat meat, Marco? Are your molars "blunt"? What does that tell
you --if anything....?
That humans are PREDOMINANTLY frugi-herbivores. Can't you read??
> > More probable is a diet of sedges and other marshland plants
supplemented with fruits and animals (e.g. tools attributed to A. robustus
now suggest termite-eating30).
> Why "marshland plants" ? Why not "savanna grasses" (seeds)?
Because you can't read.
> > Independent lines of evidence thus suggest that different australopith
species regularly waded for shallow-water plants,
> WHAT evidence? You familiarize yourself with the term taphonomy yet? How
long have you had to work it out? 10 years? 20?
Don't ask IMBECILIC questions.
> > possibly like lowland gorillas do today15, only much more frequently.
> Really? Where's your evidence for the "frequency" of wading for shallow
water plants?
If your dentition (microwear, isotopes...) suggests the consumption of
marshland plants, why wouldn't you WADE? Forgotten that apiths are partly
bipedal?
> > Papyrus or reed sedges were abundant in australopith environments (Table
2) and are part of the diet of extant hominids.
> So are grass seeds.
In order to avoid other stupid remarks of you, I suggest you finally read my
paper "Did robust australopithecines partly feed on hard parts of
Gramineae?" Hum.Evolution 7: 63-64, 1992. Gramineae are grasses, didn't you
know?? You can find the paper at
http://allserv.rug.ac.be/~mvaneech/Fil/Verhaegen_Human_Evolution.html
> > Gorillas eat bamboo shoots and stalks, as well as swamp herbs and sedges
(Table 1); all hominids eat cane; bipedally wading chimpanzees and humans
collect water-lilies; and rice growing in shallow water and other cereals
are staple foods for humans.
> This is not evidence in support of your contention that a'piths ate
marshland plants. This is merely handwaving and empty verbiage. Intro
students get their butts chewed for doing just this sort of
"research". ----------- Michael Clark
Yes, it's apparently an unusual approach for biased savanna believers like
you...
Marc Verhaegen
> [macro]
>
> Nowhere have I stated, either in print or on a public platform, or on the
> media, that I support the AAH!
>
> [..]
>
> With best wishes,
>
> Yours sincerely,
>
> (Professor Emeritus) Phillip V. Tobias
>
> > I hope you know there's a difference between saying "SH is wrong" & "SH
is
> > not necessarily correct"
http://allserv.rug.ac.be/~mvaneech/outthere.htm Repudiation of the Savannah
Hypothesis - My disavowal of SH was based in the first place on evidence
which had been coming forth from excavations in South and East Africa. From
Sterkfontein, suggestions of greater woodland cover at the time when
Australopithecus was deposited in Member 4, had emerged from studies on
fossil pollen, but these were not compelling. Then Wits team member Marian
Bamford identified fossil vines or lianas of Dichapetalum in the same Member
4: such vines hang from forest trees and would not be expected in open
savannah. The team at Makapansgat found floral and faunal evidence that the
layers containing Australopithecus reflected forest or forest margin
conditions. From Hadar, in Ethiopia, where "Lucy" was found, and from Aramis
in Ethiopia, where Tim White's team found Ardipithecus ramidus, possibly the
oldest hominid ever discovered, well-wooded and even forested conditions
were inferred from the fauna accompanying the hominid fossils. All the
fossil evidence adds up to the small-brained, bipedal hominids of four to
2.5 million years ago having lived in a woodland or forest niche, not
savannah.
Marc Verhaegen
>
> "Marc Verhaegen" <fa20...@skynet.be> wrote in message
> news:3e10cd61$0$29627$ba62...@news.skynet.be...
> >
> > "Bob Keeter" <rke...@earthlink.net> wrote in message
> > news:BA362A0E.232CF%rke...@earthlink.net...
> >
> > > Just as I hope that advocating a clear and logical consideration (and
> > possibly refutation of the AAH) is NOT the same as supporting the AAH!
> >
> > Sigh. For the 100th time, idiot, nobody ever said that. For Tobias'
opinion
> > on the matter just read his own paper
> > http://allserv.rug.ac.be/~mvaneech/outthere.htm Did he say there he
> > supports "AAH" (whatever that may mean)??
>
> No, STUPID, this is what he said:
>
> Nowhere have I stated, either in print or on a public platform, or on the
> media, that I support the AAH!
Marc Verhaegen
"Curious Amateur" <no_...@home.guv> wrote in message
> >> First, I'll point out you've snipped a lot from my previous article,
Marc.
> >CA, I'm going to snip everything. Sorry, I think you're a nice guy & I'm
sure you mean what you're saying, but there are more pleasant things to do
than repeating everything that has been discussed here many times. I realise
you're unconvinceable (because too biased IMO) - why should I do the effort?
(Please inform on the things you're discussing: you hadn't even heard of
Kenyanthropus! If you really want to understand what I'm saying on apiths
(has nothing to do with AAT) please read my Hum.Evolution papers
http://allserv.rug.ac.be/~mvaneech/Fil/Verhaegen_Human_Evolution.html )
Best - until I have more time perhaps. Marc
> Well, I'm disappointed, Marc. No, I won't be wasting more time on
you. I did that in my previous article and you've seen fit to discard it as
"too biased". It is too obvious you do not practice "good science", Marc.
You discard facts you do not like, regardless of how true they are.
No, you did. There are still a few unanswered posts of mine.
> Marc, in North America we have an epidemic of obesity. A lot of scientific
work has gone into understanding the mechanisms that affect SC fat. SC fat
is created by using fewer calories than are taken in. SC fat is burned by
using more calories than are taken in. It is well understood here that it is
an adaptive trait to deal with 'feast or famine' scenarios (seasonal
variations in the availability of food).
Yes, why not, I never denied storage of calories may be the most important
reason why our SC fat is used today, but again: the point is: why do humans
have 10 times more adipocytes than chimps have? Why do you believe chimps
don't suffer from possible famines?? Why do you refuse to answer that
question? You're hopelessly biased, CA: you try to explain every human
feature by its possible present functions, but you "forget" to explain why
these features are absent in nonhuman primates, IOW, your explanations are a
just-so story. Sorry, I think reading further is a waste of time.
Marc
Michael Clark
>
> "Michael Clark" <bit...@spammer.com> wrote in message
> news:v11p4bp...@corp.supernews.com...
>
> > > Our tooth microwear studies indicate that A. afarensis molar enamel has
> a glossy polished surface that is typical of the molars of capybaras
> Hydrochoerus hydrochaeris and mountain-beavers Aplodontia rufa24. Both these
> semi-aquatic rodents feed mainly on riverside herbs, grasses and the bark of
> young trees. The microwear of Australopithecus boisei displays more pits,
> wide parallel striations and deep-recessed occlusal dentine features when
> compared to A. afarensis25,26, resembling that of beavers Castor fiber,
> which feed on riverine herbs, roots of water-lilies, bark and woody plants.
> Apparently, an early australopith diet of fruits (larger front-teeth) and
> swamp herbs (polishing) was supplemented with woody plants in the robust
> australopiths (more wear). Walker's suggestion that A. boisei were
> bulk-eaters of "small, hard fruits with casings, pulp, seeds and all"27
> could explain the deep-recessed dentine, but not the heavily polished enamel
> that is typical of marsh-plant feeders24,25.
>
> > Is the "polish" (a highly subjective term) seen "ONLY" in capybaras?
>
> Finally willing to discuss the matter?
> :-)
> If you had really read the above you would have known my answer:
> 1) Didn't you see the word "mountain beavers"??
Is the "polish" (a highly subjective term) seen "ONLY" in capybaras and
and mountain-beavers ?
http://www.scanning-fams.org/scanabstracts/SCANNING02/24144.html
> 2) "Typical" is the word Puech used. He's not aware of exceptions AFAIK.
So what would qualify as "atypical"?
> 3) The glossy aspect of the surface comes from polishing by the wet plants
> of course.
You are assuming your conclusion --again.
> > Answer the question.
>
> I have. Why wouldn't I answer that question??
No, you have not answered the question. I don't know, Marco,
why wouldn't you honestly address your critics?
> > Don't tell me that it comes exclusively from "marsh plants" when you KNOW
> that it comes from a variety of sources. DON'T LIE!
>
> The liar tells me not to lie!? Man, you're sick.
>
> And don't SHOUT.
So it looks to me like you have not dealt with my objection above. "Polish"
is ~not~ the exclusive domain of wetland plants --and you know this as it
has been pointed out many times.
> > > These microwear data are consistent with two studies on South-African
> australopiths28,29.
>
> > Since these are qualitative assessments, they would be "consistent" with
> darn near anything. Note that neither of these sources ~support~ your story
> that A'piths were exclusive eaters of "marsh plants"
>
> LIAR. Ourt story is NOT that apiths were exclusive marsh plant eaters. Had
> you read the relevant literature you would have known.
Shouting, Marco? Then you have no problem describing a'piths as opportunistic
omnivores. Gee, no smoke...er, "dripping" gun there.
> > > Sillen provides three possibilities for low strontium:calcium ratios in
> A. robustus: partial carnivory; eating leaves and shoots of forbs and woody
> plants; and eating food derived from well-drained streamside soils28.
> Sponheimer and Lee-Thorp state that A.africanus "ate not only fruits and
> leaves but also large quantities of carbon-13-enriched foods such as grasses
> and sedges or animals that ate these plants, or both"29. However, regular
> consumption of savannah grasses is incompatible with the polished, rounded
> microwear24,29
>
> > WHY?! What about grass SEEDS?
>
> INCOMPATIBLE. if you had read the relevant literature you would have know.
> Seeds give a very different microwear.
Do they? What sort of microwear is that?
> > Where are opal phytoliths found? You need to provide an answer to ~each~
> of these questions --note the ~question marks~ . What the hell is wrong
> with "savanna grasses", Marco?
>
> You're a real FOOL. An uninformed idiot with a big MOUTH. Apparently you
> haven't even read Sponheimer&L-T's paper!?
Here it is:
http://www.indiana.edu/~origins/X-PDF/Sponheimer&LeeThorpe.pdf.
Several times.
> EVERYTHING is wrong with savanna grasses: they produce a completely
> different microwear: not glossy, but fabric-like microwear. You would have
> known that if you had informed a little bit:
http://www.tunl.duke.edu/~cosen/cosen/field.html
http://comp.uark.edu/~pungar/index.html
http://www.clas.ufl.edu/users/daegling/research/microwear.html
> "Dental studies suggest that whereas gracile australopithecines preferred
> softer fruits and vegetables, the robusts' diet included harder food items
> (e.g. Robinson, 1954; Du Brul, 1977; Walker, 1981; Puech, 1992; Lee-Thorp et
> al., 1994). Estimates of robust australopithecine bite force suggest
> 'low-energy food that had to be processed in great quantities' and food
> objects 'hard and round in shape' (Demes & Creel, 1988). Du Brul (1977)
> noticed dental parallelisms between the robust australopithecines and the
> bamboo-eating giant panda Ailuropoda melanoleuca (broad, high and heavy
> cheekbones, reduced prognathism and front teeth, broad back teeth, premolar
> molarisation), as opposed to gracile australopithecines, respectively
> non-panda bears.
Really. Now, this is fascinating. What does it mean --exactly?
> Papyrus and reed were present in the paleo-environment
> of the later australopithecines (e.g. Olduvai, Chesowanja, Kromdraai), and
> Cyperaceae and Gramineae are part of the diet of living African hominoids.
> Gorillas eat sedges and bamboo shoots and stalks, gorillas and chimpanzees
> eat cane, chimps and humans eat water lilies, and rice and other cereals are
> staple food for humans. Supplementing their diet with parts of grasslike
> plants might have been enabled the robusts to bridge the dry season, when
> fruits and soft vegetables were scarce.
And Spon & L-T said those parts were.....?
> Studies of dental enamel
> microwear provide other details. In the early australopithecines of
> Garusi-Laetoli and Hadar (A. afarensis 4-3 Myr BP), the cheekteeth enamel
> has a polished surface and the microwear looks like that of the capybara
> Hydrochoerus hydrochaeris and that of the mountain beaver Aplodontia rufa
> (Puech et al., 1986). These animals are semi-aquatic rodents that feed
> mainly on sappy marsh and riverside herbs, grasses and bark of young trees.
Gee, Marco, your macros are a bit redundant, don't you think?
(see above)
> It has recently become clear that Western lowland gorillas G. g. gorilla
> spend some time eating aquatic herbaceous vegetation (AHV) like
> Hydrocharitaceae herbs and Cyperaceae sedges (Doran & McNeilage, 1997).
So?
> Comparisons of molar enamel in South African fossils show that A. robustus
> ate substantially more hard food items than A. africanus (Grine & Kay,
> 1988). Incisal microwear suggests that A. robustus may have ingested foods
> that required less extensive incisal preparation than the foods consumed by
> A. africanus, such as fruits (Ungar & Grine, 1991), and 'incisors need not
> be employed in the manipulation of hard objects' (Ungar & Grine, 1989).
> The enamel of the East African robusts (Olduvai and Peninj) displays more
> pits, wide parallel striations and deep recessed dentine, resembling that of
> the beaver Castor fiber, that eats riverine and riverside herbs, roots of
> water lilies, bark and woody plants in a temperate climate. 'Many food
> plants growing in marsh land and +++ indeed many grasses, +++ have high
> concentrations of siliceous particles known as opal phytoliths.
...indeed many grasses...
> The
> consumption of such foods produces a great deal of wear, and the enamel and
> dentine have a blunted appearance. Ancient Egyptians ate papyrus shoots
> (Puech et al., 1983b) and we suppose that [O.H.16] did the same with swamp
> margin plants' (Puech, 1992). Whereas the East African robusts seem to have
> had aquatic plants and papyrus shoots in their diet and ate more woody
> plants than the earlier australopithecines, habilis O.H.16 apparently
> supplemented the AHV of the earlier australopithecines
What is AHV, Marco? Is that "~aquatic~ herbaceous vegetation"? Isn't
that what you were trying to establish? Why are you speaking now as if
it's a done deal....?
> with acid fruits
> (Puech, 1984). In the habilis cheekteeth, the margins of the striae have
> been polished and slightly etched, resembling the microwear of the coypu
> Myocastor coypus. This rodent feeds on reed, sedges, marsh plants, fruits
> and molluscs in river and lake margins. It thus seems that an early
> australopithecine diet of fruits (larger front teeth) and AHV (polishing)
> was supplemented with unripe fruits (acid etching) in habilis, and with
> woody plants in the robusts (more wear).
These are your conclusions, right? I would encourage you to ~read~
(how do you say it --inform a bit) Sponheimer & Lee-Thorp's paper.
Here it is again:
http://www.indiana.edu/~origins/X-PDF/Sponheimer&LeeThorpe.pdf.
> The suggestion of Walker (1981)
> that A. boisei KNM-ER 406 and 729 were bulk-eaters of whole fruits, 'small,
> hard fruits with casings, pulp, seeds and all', could explain the deep
> recessed occlusal dentine, but not the glossy appearance of heavily polished
> enamel, which is more typical for marsh plant feeders. In terrestrial
> grazers such as sheep, tooth wear is faster, with a different gradient and
> fabric-like grooves."
>
>
> > Is this another of your desperate attempt to separate a'piths from the
> savanna? Hmmm?
>
> SILLY IDIOT. You are completely INCAPABLE of giving 1 SINGLE argument in
> favour of your IDIOTIC savanna nonsense, and you speak of desperate??
> :-D
I think I've given several. Are you shouting, Marco?
> > > and predominant meat eating is unlikely in view of the blunt molars27.
>
> > Do you eat meat, Marco? Are your molars "blunt"? What does that tell
> you --if anything....?
>
> That humans are PREDOMINANTLY frugi-herbivores. Can't you read??
I read rather well. I've even read:
http://www.indiana.edu/~origins/X-PDF/Sponheimer&LeeThorpe.pdf.
> > > More probable is a diet of sedges and other marshland plants
> supplemented with fruits and animals (e.g. tools attributed to A. robustus
> now suggest termite-eating30).
>
> > Why "marshland plants" ? Why not "savanna grasses" (seeds)?
>
> Because you can't read.
Is that why, Marco?
> > > Independent lines of evidence thus suggest that different australopith
> species regularly waded for shallow-water plants,
>
> > WHAT evidence? You familiarize yourself with the term taphonomy yet? How
> long have you had to work it out? 10 years? 20?
>
> Don't ask IMBECILIC questions.
Yes, yes, taphonomy relates to your *other* problem, doesn't it....
> > > possibly like lowland gorillas do today15, only much more frequently.
>
> > Really? Where's your evidence for the "frequency" of wading for shallow
> water plants?
>
> If your dentition (microwear, isotopes...) suggests the consumption of
> marshland plants, why wouldn't you WADE? Forgotten that apiths are partly
> bipedal?
No, I haven't forgotten about a'pith's obligate bipedalism. What evidence do
you have that a'piths ~waded~ "much more frequently" than lowland gorillas?
Try not to shout....
> > > Papyrus or reed sedges were abundant in australopith environments (Table
> 2) and are part of the diet of extant hominids.
>
> > So are grass seeds.
>
> In order to avoid other stupid remarks of you, I suggest you finally read my
> paper "Did robust australopithecines partly feed on hard parts of
> Gramineae?" Hum.Evolution 7: 63-64, 1992. Gramineae are grasses, didn't you
> know?? You can find the paper at
> http://allserv.rug.ac.be/~mvaneech/Fil/Verhaegen_Human_Evolution.html
Been there, done that. Not very impressive.
> > > Gorillas eat bamboo shoots and stalks, as well as swamp herbs and sedges
> (Table 1); all hominids eat cane; bipedally wading chimpanzees and humans
> collect water-lilies; and rice growing in shallow water and other cereals
> are staple foods for humans.
>
> > This is not evidence in support of your contention that a'piths ate
> marshland plants. This is merely handwaving and empty verbiage. Intro
> students get their butts chewed for doing just this sort of
> "research". ----------- Michael Clark
>
> Yes, it's apparently an unusual approach for biased savanna believers like
> you...
Ah yes, Bishop Verhaegen, (of the Church of the Holy Wet Ape) if this were
a different age, you'd be burning me at the stake.
Jim McGinn
> > Gorillas eat bamboo shoots and stalks, as well as swamp
> > herbs and sedges (Table 1); all hominids eat cane; bipedally wading
> > chimpanzees and humans collect water-lilies; and rice growing in shallow
> > water and other cereals are staple foods for humans.
>
> This is not evidence in support of your contention that a'piths ate marshland
> plants. This is merely handwaving and empty verbiage. Intro students get
> their butts chewed for doing just this sort of "research".
I don't see what the big controversy is here. Humans tend to be
associated with rivers and lakes. This is hardly surprising when you
consider that humans are associated with seasonal babitat. And
therein locations close to rivers and lakes tend to minimize the
environmental extremes associated with seasonal habitat.
If seasonal habitat did not exist on this planet niether would humans.
Jim
Curious Amateur
That's alright, Marc. We went through these arguments a few years ago and you
ran out when the questions became to tough and your answers too absurd to
continue with any credibility whatsoever. I was curious to see if you'd
learned anything from that, and apparently you haven't.
You can claim I didn't answer your questions, but I did. Anyone reading my
articles will see them, including you.
Accepting that SC fat is used for the "storage of calories" won't change your
claims that SC fat was developed to keep us warm while wading in warm tropical
waters, will it? You won't analyze why SC fat is used for the storage of
calories, will you? All the rhetorical questions you ask about SC fat and why
it exists devolves down to storage of calories, not keeping us warm in water
(notice how SC fat does -not- accumulate around vital organs to keep them
warm, but rather around the legs, butt and stomach which contain no vital
organs endangered by cold water [cold water which doesn't exist in the
tropics, right?]).
You'll just go on claiming SC fat was invented to keep us warm in warm
tropical waters, right? You'll continue to ask people what else it could be
used for, right? You'll claim short-haired animals are hairless, and continue
to cite savannah animals like elephant and rhino as 'semi-aquatic, hairless'
examples of AAT in action. You'll point to cetacea and sirenia while ignoring
pinnipedia, right? You'll continue to fail to notice that furry creatures with
extensive aquatic adapations demonstrate the foolishness of claiming we lost
our hair to become aquatic.
Right?
Sorry, Marc, but AAT is right up there with "man as old as coal". A fairy tale
you cannot justify against a "curious amateur" such as myself. I can only
imagine how foolish you look to those who practice science full time.
CA
firstjois
:
:
: No, STUPID, this is what he said:
:
: Nowhere have I stated, either in print or on a public platform, or on the
: media, that I support the AAH!
:
: [..]
:
: With best wishes,
:
: Yours sincerely,
:
: (Professor Emeritus) Phillip V. Tobias
: ----------
: Michael Clark
Finally an answer that Marco deserves!
Jois
Bob Keeter
firstjo...@hotmail.com wrote on 12/31/02 4:19 PM:
But "deserving" sadly does not mean "hearing"!
Regards
bk
Marc Verhaegen
"Curious Amateur" <no_...@home.guv> wrote in message
> >Yes, why not, I never denied storage of calories may be the most
important reason why our SC fat is used today, but again: the point is: why
do humans have 10 times more adipocytes than chimps have? Why do you believe
chimps don't suffer from possible famines?? Why do you refuse to answer that
question? You're hopelessly biased, CA: you try to explain every human
feature by its possible present functions, but you "forget" to explain why
these features are absent in nonhuman primates, IOW, your explanations are a
just-so story. Sorry, I think reading further is a waste of time.
> That's alright, Marc. We went through these arguments a few years ago and
you ran out when the questions became to tough
No, no, when answering became too though: it's difficult to explain
something in a foreign language to people who are unable to understand.
> and your answers too absurd to continue with any credibility whatsoever. I
was curious to see if you'd learned anything from that, and apparently you
haven't.
Apparently *you* haven't, CA.
> You can claim I didn't answer your questions, but I did. Anyone reading my
articles will see them, including you. Accepting that SC fat is used for
the "storage of calories" won't change your claims that SC fat was developed
to keep us warm while wading in warm tropical waters, will it?
Of course not: again: why do you believe chimps don't have to store energy??
why can they do with 10 times less fat tissue? That's the question you're
unable to answer.
> You won't analyze why SC fat is used for the storage of calories, will
you?
What is this for a question? Analyze SC fat? Of course it's used for storage
of calories. Why not IYO?? Does this exclude other functions?
> All the rhetorical questions you ask about SC fat and why it exists
devolves down to storage of calories, not keeping us warm in water (notice
how SC fat does -not- accumulate around vital organs to keep them warm,
CA, please, no nonsense. Inform a learn abit about thermoregulation &
isolation in mammals, eg, try to understand a little bit about brown & white
fat.
> but rather around the legs, butt and stomach which contain no vital organs
endangered by cold water [cold water which doesn't exist in the tropics,
right?]).
Obviously you don't have any insight in thermoregulation. Ever heard of
brown fat?
> You'll just go on claiming SC fat was invented to keep us warm in warm
tropical waters, right?
Invented?? No, no. You still don't know what we are claiming??
> You'll continue to ask people what else it could be used for, right?
No, no, I only want you to think a bit. Fat can have a lot of funtions. I
discussed these in my book.
> You'll claim short-haired animals are hairless
Don't be ridiculous, CA. Why wouldI??
> , and continue to cite savannah animals like elephant and rhino as
'semi-aquatic, hairless' examples of AAT in action.
Again: don't be ridiculous, CA. It's you who have an unshaded view.
> You'll point to cetacea and sirenia while ignoring pinnipedia, right?
Don't be ridiculous. Why should I??
> You'll continue to fail to notice that furry creatures with extensive
aquatic adapations demonstrate the foolishness of claiming we lost our hair
to become aquatic.
You're a liar, CA.
Marc Verhaegen
> > > > Our tooth microwear studies indicate that A. afarensis molar enamel
has a glossy polished surface that is typical of the molars of capybaras
Hydrochoerus hydrochaeris and mountain-beavers Aplodontia rufa24. Both these
semi-aquatic rodents feed mainly on riverside herbs, grasses and the bark of
young trees. The microwear of Australopithecus boisei displays more pits,
wide parallel striations and deep-recessed occlusal dentine features when
compared to A. afarensis25,26, resembling that of beavers Castor fiber,
which feed on riverine herbs, roots of water-lilies, bark and woody plants.
Apparently, an early australopith diet of fruits (larger front-teeth) and
swamp herbs (polishing) was supplemented with woody plants in the robust
australopiths (more wear). Walker's suggestion that A. boisei were
bulk-eaters of "small, hard fruits with casings, pulp, seeds and all"27
could explain the deep-recessed dentine, but not the heavily polished enamel
that is typical of marsh-plant feeders24,25.
> > > Is the "polish" (a highly subjective term) seen "ONLY" in capybaras?
> > Finally willing to discuss the matter? :-) If you had really read the
above you would have known my answer: 1) Didn't you see the word "mountain
beavers"??
> Is the "polish" (a highly subjective term
Not highly, see Grine's paper below.
> ) seen "ONLY" in capybaras and and mountain-beavers ?
http://www.scanning-fams.org/scanabstracts/SCANNING02/24144.html FE Grine,
PS Ungar & MF Teaford 2002 "Error Rates in Dental Microwear Quantification
Using Scanning Electron Microscopy" Scanning 24, 144-153
fgr...@notes.cc.sunysb.edu There is a degree of correlation between dietary
habits & dental microwear in extant primates, and this has enabled
inferences to be made about prehistoric diets. Several techniques have been
used to quantify microwear, but the comparability of results derived from
each has not been demonstrated. Moreover, neither intra- nor inter-observer
error rates in microwear quantification have been documented to date. We
here assess intra- & inter-observer error using Microware 4.0, and evaluate
inter-technique comparability using the 3 methods that have been most widely
employed in the field. This study documents an overall intra-observer error
rate of about 7 %, and an overall inter-observer error rate of some 9 %.
Both intra- & inter-observer error appears to be influenced substantially by
the nature of the micrograph being measured. In no instance did the results
obtained by different observers using Microware 4.0 differ significantly,
and there was a reasonable degree of inter-observer consistency in the rank
ordering of micrographs in relation to any given parameter. The results
obtained through the use of different quantitative techniques differed
significantly, with an overall inter-technique error rate of approximately
19 %. Several variables, including differences in magnification factor,
scanning electron microscope kV settings, and specimen detector
relationships undoubtedly contribute to the differences among the 3 methods,
but we were not able to assess their rel. importance. Microwear
quantification permits distinctions betw.broad dietary categories, but the
margin of intra- & inter-observer error should be taken into account when
defining pattern differences betw.populations or spp, or when documenting
seasonally mitigated differences within a taxon. In view of the error
introduced by the use of different methods, we suggest that a consistent
technique, such as offered by the Microware software package, be adopted by
current researchers to establish a common microwear database.
Thanks for the paper. It says nothing on capibaras or so. Grine etc. say the
method is not standardised, but researchers generally agree.
- P-F.Puech 1992 "Microwear studies of early African hominid teeth" Scanning
Microscopy 6:1083-8.
- P-F.Puech cs.1986 "Dental microwear features as an indicator for plant
food in early hominids: a preliminary study of enamel" Hum.Evol.1:507-515.
- P-F.Puech 1984 "Acidic-food choice in Homo habilis at Olduvai" Current
Anthropology 25:349-350
Puech was so surprised (like all of us, he was a savanna believer at the
time) when he studied the Afar teeth electronmicroscopically when he saw the
polishing (most likely by wet plants) that he believed afarensis (a presumed
savanna runner!) used wetland plants for cleansing the dentition & gums! The
solution is far more simple he now agrees: like other hominids (eg, lowland
gorillas) they these plants were simply part of the apith diet.
The microwear information on apiths suggests this:
- afarensis: predom. wetland plants (conform to where the fossils lay),
- robust: idem + more woody plants (more enamel damage),
- habilis: wetland plants + etching by acidic fruits (possibly papyrus
shoots, says Puech: conform to where the fossils lay, eg, Conroy 1990
"Primate evolution": "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."
The picture is quite clear, don't you think? Apiths lived in wetlands. They
were bipedal+climbing. The microwear suggests they ate wetland plants. Some
lowland gorilla populations regularly wade in search for wetland plants. Why
on earth do some idiots here still believe that apiths ran over the African
plains in search for I don't know what?? Be a bit realistic.
We can even follow the probable evolution of the diet (apart from, eg,
fruits: soft fruit consumption can't be seen in dental microwear, but
exclusive soft fruit eaters usu. have large & broad incisors): ca.2.2 Ma,
the early apith diet split into a diet that included more woody & hard
plants (eg, bamboo, reed sedges...) in the large robust apiths, and into a
more frugi-omnivorous one in small apiths. This could have been related to
the cooling at the time. Comparable dentitional changes are seen in other
herbivores in E.Africa at that time (robust apiths cf. molarisation in
rhinos, suids, equids...).
Note the microwear of erectus is very different from that of the apiths
(habilis s.s. was an apith).
> > 2) "Typical" is the word Puech used. He's not aware of exceptions AFAIK.
> So what would qualify as "atypical"?
Nothing AFAIK. It's striking that all polished enamels are seen in wetland
feeders.
> > 3) The glossy aspect of the surface comes from polishing by the wet
plants of course.
> You are assuming your conclusion --again.
Yes: polishing typically seen in wetland feeders. Water is used for
polishing purposes. Why wouldn't the wet plants have caused the polishing
IYO?
> "Polish" is ~not~ the exclusive domain of wetland plants
Ah? You have relevant information? Let's hear.
> --and you know this as it has been pointed out many times.
?? Where? Man, you see ghosts.
> > > > These microwear data are consistent with two studies on
South-African australopiths28,29.
> > > Since these are qualitative assessments, they would be "consistent"
with darn near anything. Note that neither of these sources ~support~ your
story that A'piths were exclusive eaters of "marsh plants"
> > LIAR. Ourt story is NOT that apiths were exclusive marsh plant eaters.
Had you read the relevant literature you would have known.
> Shouting, Marco?
Of course I shout at IDIOTS who shout at me.
> Then you have no problem describing a'piths as opportunistic omnivores.
Gee, no smoke...er, "dripping" gun there.
?? dripping gun? Why am I losing my time with this idiot?
> > > > Sillen provides three possibilities for low strontium:calcium ratios
in A.robustus: partial carnivory; eating leaves and shoots of forbs and
woody plants; and eating food derived from well-drained streamside soils28.
Sponheimer and Lee-Thorp state that A.africanus "ate not only fruits and
leaves but also large quantities of carbon-13-enriched foods such as grasses
and sedges or animals that ate these plants, or both"29. However, regular
consumption of savannah grasses is incompatible with the polished, rounded
microwear24,29
> > > WHY?! What about grass SEEDS?
> > INCOMPATIBLE. if you had read the relevant literature you would have
know. Seeds give a very different microwear.
> Do they?
*Read* Sponh.+LT, you fool, instead of claiming you have read it:
"Theropithecus gelada consumes grass blades, seeds, and roots nearly
exclusively ... the large difference in microwear features between
Theropithecus and A.africanus ..."
> What sort of microwear is that?
Do your own homework.
> > > Where are opal phytoliths found? You need to provide an answer to
~each~ of these questions --note the ~question marks~ . What the hell is
wrong with "savanna grasses", Marco?
> > You're a real FOOL. An uninformed idiot with a big MOUTH. Apparently you
haven't even read Sponheimer&L-T's paper!?
> Here it is:
http://www.indiana.edu/~origins/X-PDF/Sponheimer&LeeThorpe.pdf. Several
times.
- You only read what you like to read. "Theropithecus gelada consumes grass
blades, seeds, and roots nearly exclusively ... the large difference in
microwear features between Theropithecus and A.africanus ..." You hadn't
even read that Theropith.microwear is largergy different from that of
africanus??
- If you want more info on opal phytoliths, see the Ciochon paper below.
> > EVERYTHING is wrong with savanna grasses: they produce a completely
different microwear: not glossy, but fabric-like microwear. You would have
known that if you had informed a little bit:
> http://www.tunl.duke.edu/~cosen/cosen/field.html
Yes, inscribe, man, and stay there.
> http://comp.uark.edu/~pungar/index.html
Interesting, but why do you send us this twice? See my comments above.
> http://www.clas.ufl.edu/users/daegling/research/microwear.html
Thanks, Clark, very interesting. "Dental Microwear - Few techniques offer a
more direct means to assess dietary adaptations in the fossil record than
dental microwear analysis. This method involves examining the occlusal
surfaces of teeth for the gouges and striations caused by masticated food
items. Critical to the success of microwear studies is the discovery of how
feeding behavior and food items interact to produce distinctive microwear
signatures. An example of the utility of microwear as a source of
paleobiological inference is the case of Gigantopithecus blacki, the largest
primate that ever lived. With Dr. Fred Grine of SUNY Stony Brook, I tested
the hypothesis that this extinct ape subsisted on bamboo by comparing its
microwear patterns to those of two living bamboo feeders, Hapalemur (the
gentle lemur) and Ailuropoda (the giant panda). To our surprise, it appears
that Gigantopithecus was a fairly eclectic feeder with no obvious dietary
specialization -- a conclusion belied by the massive jaws of this primate."
In my 1992 paper "Did Robust Australopithecines Partly Feed on Hard Parts of
Gramineae?" Human Evolution 7: 63-64, 1992
http://allserv.rug.ac.be/~mvaneech/Fil/Verhaegen_Human_Evolution.html I
suggested: "It must be possible to test this hypothesis by comparing molar
enamel microwear of Gigantopithecus, Paranthropus and Ailuropoda." Daegling
& Grine did part of this: "Bamboo feeding, dental microwear, and diet of the
Pleistocene ape Gigantopithecus blacki" S.Afr.J.Sci.90:527-532, 1994. I
thank them for this. :-)
- J-L Voisin & A-M Bacon 2002 "Who was Giantopithecus?" Fol.prim.73:164: ".
The shape of the teeth indicates a herbivorous diet, with a high consumption
of bamboo, esp. for the sp.G.blacki. Mandibles are 3 x bigger than those of
male gorillas."
- RL Ciochon, DR Piperno & RG Thompson 1990 "Opal phytoliths found on the
teeth of the extinct ape Gigantopith.blacki: implications for paleodietary
studies" PNAS 87:8120-4: "Identification of opal phytoliths bonded to the
enamel surface of the teeth of Gi.blacki indicates that this extinct ape had
a varied diet of grasses & fruits. By using the scan.e_microscope at
magnifications of 2000-6000x, specific opal phytoliths were observed &
photographed on the fossilized teeth of an extinct species. Opal phytoliths
represent the inorganic remains of once-living plant cells, their
documentation on Gi.teeth of introduces a promising technique for diet
determination in extinct mamm.spp, which should find numerous applications
in the field of PA as well as vert.paleontology."
BTW, if had really read it, you would have found in Daegling's URL some
answers to your question about differences betw. apith & gelada enamel
microwear.
> > Papyrus and reed were present in the paleo-environment of the later
australopithecines (e.g. Olduvai, Chesowanja, Kromdraai), and Cyperaceae and
Gramineae are part of the diet of living African hominoids. Gorillas eat
sedges and bamboo shoots and stalks, gorillas and chimpanzees eat cane,
chimps and humans eat water lilies, and rice and other cereals are staple
food for humans. Supplementing their diet with parts of grasslike plants
might have been enabled the robusts to bridge the dry season, when fruits
and soft vegetables were scarce.
> And Spon & L-T said those parts were.....?
Sedges. You only have to read to abstract. Or is even that too difficult for
you?
> > It has recently become clear that Western lowland gorillas G. g. gorilla
spend some time eating aquatic herbaceous vegetation (AHV) like
Hydrocharitaceae herbs and Cyperaceae sedges (Doran & McNeilage, 1997).
> So?
Don't you even see the relevance?? How old are you, Clark? What have you
studied? Why do you believe that something that is possible for living
hominids is impossible for extinct hominids??
> > Comparisons of molar enamel in South African fossils show that A.
robustus ate substantially more hard food items than A. africanus (Grine &
Kay, 1988). Incisal microwear suggests that A. robustus may have ingested
foods that required less extensive incisal preparation than the foods
consumed by A. africanus, such as fruits (Ungar & Grine, 1991), and
'incisors need not be employed in the manipulation of hard objects' (Ungar &
Grine, 1989). The enamel of the East African robusts (Olduvai and Peninj)
displays more pits, wide parallel striations and deep recessed dentine,
resembling that of the beaver Castor fiber, that eats riverine and riverside
herbs, roots of water lilies, bark and woody plants in a temperate climate.
'Many food plants growing in marsh land and +++ indeed many grasses, +++
have high concentrations of siliceous particles known as opal phytoliths.
> ...indeed many grasses...
Yes, that's what I've been saying the whole time, see, eg, my paper above on
Gramineae. You still don't grasp it, do you? Poor boy...
> > The consumption of such foods produces a great deal of wear, and the
enamel and dentine have a blunted appearance. Ancient Egyptians ate papyrus
shoots (Puech et al., 1983b) and we suppose that [O.H.16] did the same with
swamp margin plants' (Puech, 1992). Whereas the East African robusts seem to
have had aquatic plants and papyrus shoots in their diet and ate more woody
plants than the earlier australopithecines, habilis O.H.16 apparently
supplemented the AHV of the earlier australopithecines
> What is AHV, Marco? Is that "~aquatic~ herbaceous vegetation"? Isn't
that what you were trying to establish? Why are you speaking now as if it's
a done deal....?
Why not?
> > with acid fruits (Puech, 1984). In the habilis cheekteeth, the margins
of the striae have been polished and slightly etched, resembling the
microwear of the coypu Myocastor coypus. This rodent feeds on reed, sedges,
marsh plants, fruits and molluscs in river and lake margins. It thus seems
that an early australopithecine diet of fruits (larger front teeth) and AHV
(polishing) was supplemented with unripe fruits (acid etching) in habilis,
and with woody plants in the robusts (more wear).
> These are your conclusions, right? I would encourage you to ~read~ (how
do you say it --inform a bit) Sponheimer & Lee-Thorp's paper. Here it is
again: http://www.indiana.edu/~origins/X-PDF/Sponheimer&LeeThorpe.pdf.
Yes, *read* it, man.
> > The suggestion of Walker (1981) that A. boisei KNM-ER 406 and 729 were
bulk-eaters of whole fruits, 'small, hard fruits with casings, pulp, seeds
and all', could explain the deep recessed occlusal dentine, but not the
glossy appearance of heavily polished enamel, which is more typical for
marsh plant feeders. In terrestrial grazers such as sheep, tooth wear is
faster, with a different gradient and fabric-like grooves."
No comment. Clark agrees. :-)
> > > Is this another of your desperate attempt to separate a'piths from the
savanna? Hmmm?
> > SILLY IDIOT. You are completely INCAPABLE of giving 1 SINGLE argument in
favour of your IDIOTIC savanna nonsense, and you speak of desperate?? :-D
> I think I've given several. Are you shouting, Marco?
I shout at IDIOTS who shout at me.
Again, without shouting: You are incapable of giving 1 argument in favour of
your savanna story.
> > > > and predominant meat eating is unlikely in view of the blunt
molars27.
> > > Do you eat meat, Marco? Are your molars "blunt"? What does that tell
you --if anything....?
> > That humans are PREDOMINANTLY frugi-herbivores. Can't you read??
> I read rather well. I've even read:
http://www.indiana.edu/~origins/X-PDF/Sponheimer&LeeThorpe.pdf.
You can't *read*: you hadn't even read about the baboons.
> > > > possibly like lowland gorillas do today15, only much more
frequently.
> > > Really? Where's your evidence for the "frequency" of wading for
shallow water plants?
> > If your dentition (microwear, isotopes...) suggests the consumption of
marshland plants, why wouldn't you WADE? Forgotten that apiths are partly
bipedal?
> No, I haven't forgotten about a'pith's obligate bipedalism.
Yes, of course, it's more difficult to wade on 4 than on 2 legs, don't you
think? :-)
And please no nonsense on "obligate bipedalism": it's a slogan that doesn't
say much. R.J.Clarke 2000 "What the StW 573 Australopithecus skeleton
reveals about early hominid bipedalism" AAPA abstracts:126: "...the foot had
both bipedal & climbing capabilities, whilst the arm & hand indicate
adaptation to arboreal locomotion. This skeleton's foot morphology is
consistent with the bipedal Laetoli footprint trails, which are not those of
fully hum.feet, but which have very clear ape-like morphology."
> What evidence do you have that a'piths ~waded~ "much more frequently"
than lowland gorillas? Try not to shout....
- They were bipedal.
- They ate wetland plants.
What more evidence you you want??
Marc Verhaegen
?? I said Tobias has an open mind, unlike many of you. He said
http://allserv.rug.ac.be/~mvaneech/outthere.htm "Humans are not
savannah-adapted animals" & gave the reasons why: "In rejecting the Savannah
Hypothsis, I was moved primarily by the evidence unearthed in South Africa
But perhaps Jois is no profligate urinator?
Michael Clark
>
> "Michael Clark" <bit...@spammer.com> wrote in message
> news:v12f2b7...@corp.supernews.com...
>
> > > > > Our tooth microwear studies indicate that A. afarensis molar enamel
> has a glossy polished surface that is typical of the molars of capybaras
> > Is the "polish" (a highly subjective term
>
> Not highly, see Grine's paper below.
Yes, DO see Grine's paper below.
> > ) seen "ONLY" in capybaras and and mountain-beavers ?
> http://www.scanning-fams.org/scanabstracts/SCANNING02/24144.html FE Grine,
> PS Ungar & MF Teaford 2002 "Error Rates in Dental Microwear Quantification
> Using Scanning Electron Microscopy" Scanning 24, 144-153
This study documents an overall intra-observer error
rate of about 7 %, and an overall inter-observer error rate of some 9 %.
Both intra- & inter-observer error appears to be influenced substantially by
the nature of the micrograph being measured. [...]
.....and......
The results
obtained through the use of different quantitative techniques differed
significantly, with an overall inter-technique error rate of approximately
19 %.
> Thanks for the paper. It says nothing on capibaras or so. Grine etc. say the
> method is not standardised, but researchers generally agree.
No, it says nothing about Capybaras. That is because we were talking about
"subjective" measures. Remember? I guess not --you can call an "error
rate of approximately 19 %" ~agreement~ if you like.
> - P-F.Puech 1992 "Microwear studies of early African hominid teeth" Scanning
> Microscopy 6:1083-8.
> - P-F.Puech cs.1986 "Dental microwear features as an indicator for plant
> food in early hominids: a preliminary study of enamel" Hum.Evol.1:507-515.
> - P-F.Puech 1984 "Acidic-food choice in Homo habilis at Olduvai" Current
> Anthropology 25:349-350
>
> Puech was so surprised (like all of us, he was a savanna believer at the
> time) when he studied the Afar teeth electronmicroscopically when he saw the
> polishing (most likely by wet plants) that he believed afarensis (a presumed
> savanna runner!) used wetland plants for cleansing the dentition & gums! The
> solution is far more simple he now agrees: like other hominids (eg, lowland
> gorillas) they these plants were simply part of the apith diet.
I'll buy that. I have no problem with "a'piths sometimes ate wetland plants".
> The microwear information on apiths suggests this:
> - afarensis: predom. wetland plants (conform to where the fossils lay),
Now you say that afarensis "predom. [ate] wetland plants" and buttress
that with "where the fossils lay". This is incorrect. You have no idea based
on any kind of data that I am aware of --what, when, where, and
how a'piths ate. A depositional environment <> a living environment!!!!!
This is your "other" problem. Look up "taphonomy".
> - robust: idem + more woody plants (more enamel damage),
> - habilis: wetland plants + etching by acidic fruits (possibly papyrus
> shoots, says Puech: conform to where the fossils lay, eg, Conroy 1990
> "Primate evolution": "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."
A depositional environment <> a living environment!!!!! Are you getting
any of this?
> The picture is quite clear, don't you think? Apiths lived in wetlands.
The bones of Apiths were "deposited in wetlands", The polish observed
was/is of unkown provenance. (period)
> They
> were bipedal+climbing. The microwear suggests they ate wetland plants.
Could be wetland plants, could be darn near anything --anything with a
high concentration of opal phytoliths. Where are opal phytoliths found,
Marco?
> Some
> lowland gorilla populations regularly wade in search for wetland plants.
Big deal.
> Why
> on earth do some idiots here still believe that apiths ran over the African
> plains in search for I don't know what?? Be a bit realistic.
No living, breathing human being here "believe[s] that apiths ran over the African
plains in search for [you] don't know what". This is your standard and often
repeated non-sequitur. Put away your girly magazines and read some current
anthropology.
[handwaving]
> Note the microwear of erectus is very different from that of the apiths
> (habilis s.s. was an apith).
Habilis was an a'pith? Are you feeling alright?
[is/is not]
> > You are assuming your conclusion --again.
>
> Yes: polishing typically seen in wetland feeders. Water is used for
> polishing purposes. Why wouldn't the wet plants have caused the polishing
> IYO?
Water is used for polishing purposes? But isn't your mouth ~always~ wet?
Wetland plants can cause the polishing --because of some unkown relative
concentration of opal phytoliths. But these are not the ~only~ plants that contain
them. This nagging bit of doubt has been pointed out how many times?
Have you kept count?
> > "Polish" is ~not~ the exclusive domain of wetland plants
>
> Ah? You have relevant information? Let's hear.
Fullagar, R. L. K.
1991 The role of silica in polish formation. Journal of Archaeological Science)
18(1):1-24.
See Gerrit's posts. You remember Gerrit, don't you Marco?
From http://makeashorterlink.com/?I68551EE2,
"Monocot forbs (especially sedges) and grasses are dominant for bioproductivity
in wetlands, tall-grass prairies, and savannas." Now why is it that you can see only
one of the three (3)?
[is/is not]
> *Read* Sponh.+LT, you fool, instead of claiming you have read it:
> "Theropithecus gelada consumes grass blades, seeds, and roots nearly
> exclusively ... the large difference in microwear features between
> Theropithecus and A.africanus ..."
But I have read the paper, doofus, and I fail to see what your
quote mining above serves to accomplish. Are you saying that
baboons and apiths don't eat the same things? OK. (yawn)
[..]
> > > You're a real FOOL. An uninformed idiot with a big MOUTH. Apparently you
> haven't even read Sponheimer&L-T's paper!?
Here it is:
http://www.indiana.edu/~origins/X-PDF/Sponheimer&LeeThorpe.pdf.
Several times.
> - You only read what you like to read.
Ooooh! .sig material!
[redundancy]
> - If you want more info on opal phytoliths, see the Ciochon paper below.
Same to ya --
Phytolith bibliography: http://archaeology.miningco.com/blphytobib.htm
> > > EVERYTHING is wrong with savanna grasses: they produce a completely
> different microwear: not glossy, but fabric-like microwear. You would have
> known that if you had informed a little bit:
>
> > http://www.tunl.duke.edu/~cosen/cosen/field.html
Background information: Dental microwear analyses have the potential
to yield new insights into dental function in prehistoric animals. However,
microwear interpretations of fossil teeth are ultimately based on
comparisons with modern teeth, with most analyses of modern
teeth based on museum specimens taken from animals with
uncertain life histories. This uncertainty has effectively limited
the resolution of dental microwear analyses. In exceptional cases
subtle intraspecific differences in dental microwear have been
associated with inferred dietary differences, but generally, only the
most obvious associations between microwear and diet can be
demonstrated using museum material. For instance, primate
hardobject feeders have consistently shown molar microwear
patterns characterized by the presence of large pits (10- 100
microns in diameter) on the enamel, while primate leaf-and
foliage-eaters tend to have more scratches and fewer pits on
their molars. This level of resolution may be sufficient for certain
purposes, but it may also leave important questions unanswered:
How quickly can microwear patterns change in the face of a
variable diet? What are the effects of specific food items on
dental microwear patterns? Are age- and size-related differences
in dental microwear detectable or even distinguishable? If
questions such as these cannot be asked or answered, then
dental microwear analyses may never reach their potential.
> Yes, inscribe, man, and stay there.
Aren't these "valid" concerns, Macro Man?
> > http://www.clas.ufl.edu/users/daegling/research/microwear.html
[..]
> With Dr. Fred Grine of SUNY Stony Brook, I tested
> the hypothesis that this extinct ape subsisted on bamboo by comparing its
> microwear patterns to those of two living bamboo feeders, Hapalemur (the
> gentle lemur) and Ailuropoda (the giant panda). To our surprise, it appears
> that Gigantopithecus was a fairly eclectic feeder with no obvious dietary
> specialization -- a conclusion belied by the massive jaws of this primate."
>
> In my 1992 paper "Did Robust Australopithecines Partly Feed on Hard Parts of
> Gramineae?" Human Evolution 7: 63-64, 1992
> http://allserv.rug.ac.be/~mvaneech/Fil/Verhaegen_Human_Evolution.html I
> suggested: "It must be possible to test this hypothesis by comparing molar
> enamel microwear of Gigantopithecus, Paranthropus and Ailuropoda." Daegling
> & Grine did part of this: "Bamboo feeding, dental microwear, and diet of the
> Pleistocene ape Gigantopithecus blacki" S.Afr.J.Sci.90:527-532, 1994. I
> thank them for this. :-)
Yes. And they concluded: "Gigantopithecus was a fairly eclectic feeder with
no obvious dietary specialization."
> - J-L Voisin & A-M Bacon 2002 "Who was Giantopithecus?" Fol.prim.73:164: ".
> The shape of the teeth indicates a herbivorous diet, with a high consumption
> of bamboo, esp. for the sp.G.blacki. Mandibles are 3 x bigger than those of
> male gorillas."
> - RL Ciochon, DR Piperno & RG Thompson 1990 "Opal phytoliths found on the
> teeth of the extinct ape Gigantopith.blacki: implications for paleodietary
> studies" PNAS 87:8120-4: "Identification of opal phytoliths bonded to the
> enamel surface of the teeth of Gi.blacki indicates that this extinct ape had
> a varied diet of grasses & fruits. By using the scan.e_microscope at
> magnifications of 2000-6000x, specific opal phytoliths were observed &
> photographed on the fossilized teeth of an extinct species. Opal phytoliths
> represent the inorganic remains of once-living plant cells, their
> documentation on Gi.teeth of introduces a promising technique for diet
> determination in extinct mamm.spp, which should find numerous applications
> in the field of PA as well as vert.paleontology."
Yes, "a varied diet of grasses & fruits..." So?
> BTW, if had really read it, you would have found in Daegling's URL some
> answers to your question about differences betw. apith & gelada enamel
> microwear.
My only question is: Why do you consider the differences in microwear between
"apith & gelada" significant?
> > > Papyrus and reed were present in the paleo-environment of the later
> australopithecines (e.g. Olduvai, Chesowanja, Kromdraai), and Cyperaceae and
> Gramineae are part of the diet of living African hominoids. Gorillas eat
> sedges and bamboo shoots and stalks, gorillas and chimpanzees eat cane,
> chimps and humans eat water lilies, and rice and other cereals are staple
> food for humans. Supplementing their diet with parts of grasslike plants
> might have been enabled the robusts to bridge the dry season, when fruits
> and soft vegetables were scarce.
>
> > And Spon & L-T said those parts were.....?
>
> Sedges. You only have to read to abstract. Or is even that too difficult for
> you?
Yea, I read the abstract: " The results suggest that early hominids regularly
exploited relatively open environments such as woodlands or grasslands
for food. They may also suggest that hominids consumed high quality
animal foods before the development of stone tools and the origin of the
genus Homo." No "predominance of wetland plants" there. Further:
"Analysis of variance shows that the C values for A. Africanus are significantly
different from the values for grazers, browsers, and mixed feeders from
Makapansgat. The only taxon from which they are not significantly different
is the carnivore Hyaena makapani"
You would have had to read ~beyond~ the abstract to get that.....
> > > It has recently become clear that Western lowland gorillas G. g. gorilla
> spend some time eating aquatic herbaceous vegetation (AHV) like
> Hydrocharitaceae herbs and Cyperaceae sedges (Doran & McNeilage, 1997).
>
> > So?
>
> Don't you even see the relevance?? How old are you, Clark? What have you
> studied? Why do you believe that something that is possible for living
> hominids is impossible for extinct hominids??
I'm 48 and hold two graduate degrees. One in comp. sci. and one in
physical anthropology. Because in reading beyond the abstract I caught
sight of this: "Aepyceros sp., Gazella gracilior, and G. vanhoeperi were all
C3 consumers, despite the fact that their extant kin are generally mixed feeders.
This demonstrates the danger of assuming that fossil taxa had the same diets as
their closest extant relatives".
> > > Comparisons of molar enamel in South African fossils show that A.
> robustus ate substantially more hard food items than A. africanus (Grine &
> Kay, 1988). Incisal microwear suggests that A. robustus may have ingested
> foods that required less extensive incisal preparation than the foods
> consumed by A. africanus, such as fruits (Ungar & Grine, 1991), and
> 'incisors need not be employed in the manipulation of hard objects' (Ungar &
> Grine, 1989). The enamel of the East African robusts (Olduvai and Peninj)
> displays more pits, wide parallel striations and deep recessed dentine,
> resembling that of the beaver Castor fiber, that eats riverine and riverside
> herbs, roots of water lilies, bark and woody plants in a temperate climate.
> 'Many food plants growing in marsh land and +++ indeed many grasses, +++
> have high concentrations of siliceous particles known as opal phytoliths.
>
> > ...indeed many grasses...
>
> Yes, that's what I've been saying the whole time, see, eg, my paper above on
> Gramineae. You still don't grasp it, do you? Poor boy...
Yes, I grasp it. I grasp that 1/4 of the earths surface is covered with grasses.
> > > The consumption of such foods produces a great deal of wear, and the
> enamel and dentine have a blunted appearance. Ancient Egyptians ate papyrus
> shoots (Puech et al., 1983b) and we suppose that [O.H.16] did the same with
> swamp margin plants' (Puech, 1992). Whereas the East African robusts seem to
> have had aquatic plants and papyrus shoots in their diet and ate more woody
> plants than the earlier australopithecines, habilis O.H.16 apparently
> supplemented the AHV of the earlier australopithecines
>
> > What is AHV, Marco? Is that "~aquatic~ herbaceous vegetation"? Isn't
> that what you were trying to establish? Why are you speaking now as if it's
> a done deal....?
>
> Why not?
For all the reasons laid steaming on your plate. For all the reason that
you continue to ignore.
[..]
> Again, without shouting: You are incapable of giving 1 argument in favour of
> your savanna story.
I don't believe that you've seen me, or anyone else put forward a "savanna
theory" that resembles this straw man that you're so fond of trotting out.
What the argument here is, is your insistence on linking a'piths and early
homo with some kind of "aquatic habitat". Are you going to deny your
participation in this "wet ape" nonsense?
[..]
> http://www.indiana.edu/~origins/X-PDF/Sponheimer&LeeThorpe.pdf.
> You can't *read*: you hadn't even read about the baboons.
I suggest you read it again.
[is/is not]
> > No, I haven't forgotten about a'pith's obligate bipedalism.
>
> Yes, of course, it's more difficult to wade on 4 than on 2 legs, don't you
> think? :-)
Not at all. Ask any dog.
> And please no nonsense on "obligate bipedalism": it's a slogan that doesn't
> say much. R.J.Clarke 2000 "What the StW 573 Australopithecus skeleton
> reveals about early hominid bipedalism" AAPA abstracts:126: "...the foot had
> both bipedal & climbing capabilities, whilst the arm & hand indicate
> adaptation to arboreal locomotion. This skeleton's foot morphology is
> consistent with the bipedal Laetoli footprint trails, which are not those of
> fully hum.feet, but which have very clear ape-like morphology."
> > What evidence do you have that a'piths ~waded~ "much more frequently"
> than lowland gorillas? Try not to shout....
>
> - They were bipedal.
> - They ate wetland plants.
> What more evidence you you want??
I want evidence that addresses my question.
Lorenzo L. Love
So much for your touchy-feely ideas of having a nice polite rational
discussion with Verhaegen. You can not have a rational argument with an
irrational psychotic.
Lorenzo L. Love
http://home.thegrid.net/~lllove
"One must not assume that an understanding of science is present in
those who borrow its language"
Louis Pasteur
Curious Amateur
snip
>
>So much for your touchy-feely ideas of having a nice polite rational
>discussion with Verhaegen. You can not have a rational argument with an
>irrational psychotic.
>
>Lorenzo L. Love
>http://home.thegrid.net/~lllove
>
>"One must not assume that an understanding of science is present in
>those who borrow its language"
> Louis Pasteur
No one is demeaned by trying to have a "nice polite rational discussion" with
anyone, Lorenzo. That doesn't mean it's always possible.
Seems a person can come in here, adopt the popular judgments so as to be
popular, and not bother with a "nice polite rational" approach, or they can
determine for themselves the facts of the matter. Am I to be faulted for
giving Marc a chance to demonstrate he could behave himself while AAT was
being challenged?
I hope not. If I recall what was done to Dart and resolve not to do that to
others, am I being any less scientific in my approach than Dart's antagonists?
Marc has collected some facts which, superficially, support a theory of an
aquatic existence. Unfortunately for Marc there are a wealth of facts that
contradict his view. Marc's apparent decision to ignore the science by
rejecting 'inconvenient' facts for the sake of assuming his theory cannot be
wrong under any circumstances is quite unfortunate.
He demonstrates a 'bunker mentality' where the truth (or lack thereof) of a
fact is determined by sheer will power alone, not by scientific testing.
As I said back at the beginning of December, Marc and I have had these
discussions in SAP several years ago. I was already aware of his arguments,
aware of their weaknesses, and aware of his habit of ducking rather than
defending his statements. So none of this comes as any surprise to me now.
I had hoped he'd learned better, apparently he has not and quite possibly
cannot.
CA
Curious Amateur
>discussion with Verhaegen. You can not have a rational argument with an
>irrational psychotic.
I probably should have mentioned this earlier. Lorenzo, I used the same
"touchy-feely" approach with Philip and Erika at the beginning of the month
(Erika complained about it often then, so this was independantly verified at
the time). I'm sure if you check through the list of threads that sprang up at
the time, and the repetition of the ":-E" symbol, you will see quite a display
of what some would call "irrational psychosis".
If we compare the reaction of the two groups (Marc now compared to Philip and
Erika in December), you will find Marc's reaction to be quite mild. I know I
do.
There is no one method guaranteed to produce rationality or even good manners.
I would say that a "touchy-feely" approach is more apt to generate that kind
of reaction than other approaches I can think of (witness Ed Conrad's
approach).
Despite the nastiness, I had a good month here in SAP in December: generated a
few threads, participated in others, learned a few things about the current
state of paleo-anthropology (nods to Bob and Harry), and had the opportunity
to obsevre some interesting human behaviour along the way.
So far I've only found four individuals who did not respond well to my
"touchy-feely" approach. And let's face it, I was not so "touchy-feely" with
Marc about AAT as I was about Marc's right to post here on AAT. I challenged
his theory, not his right to post here.
While being accused of being a "liar" is unpleasant, it is nowhere near as bad
as some of the things I've seen posted about Bob or myself by those who
would not prefer to be linked with the lunatic fringe.
Truth is you could have substituted "Dietiker" with "Verhaegen" and issued
that statement three weeks ago and it would have been most appropos.
Let's keep things in perspective, shall we? I've yet to see Marc threaten
anyone with a call to their local police station to suggest the individual in
question might kidnap children, etc. I still have the quote from Philip
threatening Bob with just that kind of action. Which of the two is more of an
"irrational psychotic" I leave as an exercise for the reader.
CA
Curious Amateur
snip
>
>Truth is you could have substituted "Dietiker" with "Verhaegen" and issued
>that statement three weeks ago and it would have been most appropos.
Something was bugging me about this article. I should have written:
"Truth is you could have substituted "Dietiker" - for - "Verhaegen" and issued
that statement three weeks ago and it would have been most appropos."
My apologies for the confusion.
CA
Jim McGinn
> > Again, without shouting: You are incapable of
> > giving 1 argument in favour of your savanna story.
>
> I don't believe that you've seen me, or anyone else
> put forward a "savanna theory" that resembles this
> straw man . . .
Yes, and this is because, as Marc pointed out, you
don't have an argument at all!
Jim
Marc Verhaegen
"Jim McGinn" <jimm...@yahoo.com> wrote in message
news:ac6a5059.03010...@posting.google.com...
> "Michael Clark" <bit...@spammer.com> wrote
> > > You are incapable of giving 1 argument in favour of your savanna
story.
> > I don't believe that you've seen me, or anyone else put forward a
"savanna theory" that resembles this straw man . . .
Don't you believe human ancestors ran over the African plains? If not, what
is your scenario?
> Yes, and this is because, as Marc pointed out, you don't have an argument
at all! Jim
:-)
Marc
Marc Verhaegen
"Lorenzo L. Love" <lll...@thegrid.net> wrote in message
news:3E1362B2...@thegrid.net...
unable to answer my simple question:
Michael Clark
Sure --and this was snipped from a ~long~ post where I put
forward a considerable argument. No rebuttal from either Marco
or his new sycophant. One wonders just what Jimmy's point is.....?
They're calling for you over at sci.bio.evolution, Jimmy.
They need some more of your "world-class evolutionary
theorizing...."
> Jim
Marc Verhaegen
"Curious Amateur" <no_...@home.guv> wrote in message
> Marc has collected some facts which, superficially, support a theory of an
aquatic existence.
Not "aquatic", CA, I didn't say that, did I?
Misrepresenting our ideas is not fair.
Our scenario is this:
In 1960 Alister Hardy ("Was Man more aquatic in the past?" New Scientist)
described how a sea-side lifestyle - incl. wading, swimming, collecting
edible shells, turtles, crabs, coconuts, seaweeds etc. - could explain many
typically human features that are absent in our nearest relatives the
chimps, and that are unexplained by savanna scenarios: reduction of
climbing skills, very large brain, greater breathing control (=
preadaptation for speech), very dextrous hands (stone tool use to open
shells or nuts), reduction of fur, thicker fat tissues, longer legs, more
linear body build, high needs of iodine, sodium, poly-unsaturated fatty
acids etc.
IMO, Hardy was only wrong in thinking this seaside phase happened more than
10 Ma. Homo ergaster-erectus fossils or tools are found in Israel, Algeria,
E.Africa, Georgia, Java ca.1.8 Ma, IOW, they spread along the Mediterranean
& Indian Ocean coasts early Pleistocene or earlier. Although most
Pleistocene coasts are some 100 m below the present sea level and it's
mostly the inland Homo populations (entering the continents along the
rivers) that are represented in the fossil and archeological record, Homo
remains have frequently been found amid shells, corals, barnacles etc., from
1.8 Ma (Mojokerto) to 0.1 Ma (Eritrea), as well as on islands which could
only be reached oversea (Flores 0.8 Ma).
You don't have 1 argument that this scenario is wrong.
Marc Verhaegen
"Curious Amateur" <no_...@home.guv> wrote in message
> While being accused of being a "liar" is unpleasant,
Yes, I shouldn't have said that, CA, I meant: misrepresenting my view is
unfair.
Marc
Curious Amateur
I was not "misrepresenting" it, Marc. I was representing it to the best of my
understanding.
If you want to clarify or correct that understanding, you do not duck and run.
If you don't care, fine. You're as entitled to spend your time as you wish as
any. But don't expect acts of faith from me, Marc. I may be an amateur but I
am certainly not stupid.
I've noticed the previous article where you claim I have not one argument
against the scenario you've quoted. If you wish to pursue this with me it will
be with some understanding that we are debating the issue, not each other's
personality.
Let me know if you find this understanding satisfactory.
CA
Michael Clark
"Curious Amateur" <no_...@home.guv> wrote in message
[...]
> I was not "misrepresenting" it, Marc. I was representing it to the best of my
> understanding.
>
> If you want to clarify or correct that understanding, you do not duck and run.
> If you don't care, fine. You're as entitled to spend your time as you wish as
> any. But don't expect acts of faith from me, Marc. I may be an amateur but I
> am certainly not stupid.
>
> I've noticed the previous article where you claim I have not one argument
> against the scenario you've quoted. If you wish to pursue this with me it will
> be with some understanding that we are debating the issue, not each other's
> personality.
>
> Let me know if you find this understanding satisfactory.
>
> CA
Having drug Verhaegens' hide out of the bit bucket, I have had occasion
to follow a bit of this back-and-forth. While I still may feel a bit uneasy
around your persona, I must say that your argument is spot on. I was
a tad hasty with the plonk and for that I have missed a good argument.
No skin off your nose I'm sure, just a bit off mine.
My bit bucket is now a bit lighter.....:-)
Michael Clark
Bit...@spammer.com
MEC
Hiya.
I'm a lurker over on T.O. and ran across this thread. I've read a bit
of it. It is a shame that this discussion has deteriorated the way it
has. I suspect there is some history here. I only have one comment
and, later, a question. First the comment. The Sponheimer paper below
has been presented to you as direct evidence of the diet of
australopiths. Although I have no expertise in this field (I am an
immunologist by training) even I can see that the authors provide no
support for your claims. Seems that they conclude two things; 1) that
a'piths had a diet that consisted largely of C4 plants, but also had
significant contributions from C3 plants. And 2) that these data
suggest that a'piths got a significant proportion of their diet from
eating animals that ate (or who, in turn, ate) animals whose diets
comprised both C3 and C4. I am not sure how one reconciles these
findings with an hypothesis that a'piths were aquatic. Are you
suggesting that the aquatic a'piths were carnivores like crocs; eating
browsers and grazers? Elsewhere in the thread you go on about wear and
polishing and some-such, but this paper doesn't appear to me to lend
you any support at all. Quite the opposite.
<snips>
> > I read rather well. I've even read:
> http://www.indiana.edu/~origins/X-PDF/Sponheimer&LeeThorpe.pdf.
>
> You can't *read*: you hadn't even read about the baboons.
>
Now the question. Modern humans have adapted to every environment on
earth. Every single one of them. Except one. Why do you suppose, if
our ancestors were aquatic, that we have been unable to adapt to that
environment when we seem to have had little trouble with any other?
<snip rest>
Lorenzo L. Love
That's quite a non sequitur even for a psychotic. But since he brought
it up, humans, gorillas and orangutans all get immensely fat when given
an endless supply of food. Chimpanzees get fat but no where near like us
other apes. Chimps are the odd man out, not humans. So why do humans,
gorillas and orangutans get fat but not chimps?
Lorenzo L. Love
http://home.thegrid.net/~lllove
"In the old days being crazy meant something. Nowadays everybody's
crazy."
Charles Manson
firstjois
"MEC" <unre...@hotmail.com> wrote in message
news:c240c53.03010...@posting.google.com...
[snip]
Did I get this right?
A lurker undergrad comes into this discussion and says; "Although I have no
expertise in this field (I am an immunologist by training) even I can see
that the authors provide no support for your claims."
Marco, you are tragic!
Jois
Curious Amateur
I'm glad to hear we're in agreement and I'm glad you've found some merit in
reading at least some of my contributions.
As for your uneasiness and hastiness, I'm sure it isn't every person who
introduces themself as someone you can feel free to ignore for any reason at
any time ;-)
CA
Michael Clark
> I'm glad to hear we're in agreement and I'm glad you've found some merit in
> reading at least some of my contributions.
>
> As for your uneasiness and hastiness, I'm sure it isn't every person who
> introduces themself as someone you can feel free to ignore for any reason at
> any time ;-)
Well, I'll be darned. Graciousness, too. ....way too hasty. :-)
> CA
Marc Verhaegen
> Sure --and this was snipped from a ~long~ post where I put forward a
considerable argument.
put forward a considerable argument?? ridiculous
Marc Verhaegen
"Curious Amateur" <no_...@home.guv> wrote in message
> >> While being accused of being a "liar" is unpleasant,
> >Yes, I shouldn't have said that, CA, I meant: misrepresenting my view is
unfair. Marc
> I was not "misrepresenting" it, Marc.
You were, CA. Very much.
> I was representing it to the best of my understanding.
That may be correct...
> If you want to clarify or correct that understanding,
I've tried many times. In vain. I don't know why many PAs don't seem to
understand what we are saying. I guess unconscious prejudices? Perhaps more
important: the comparative evidence (what we see in other mammals) is much
more important than certain (prejudiced IMO) interpretations of the fossil
record.
> you do not duck and run. If you don't care, fine. You're as entitled to
spend your time as you wish as any. But don't expect acts of faith from me,
Marc. I may be an amateur but I am certainly not stupid.
OK, although I think you're often ill-informed.
> I've noticed the previous article where you claim I have not one argument
against the scenario you've quoted. If you wish to pursue this with me it
will be with some understanding that we are debating the issue, not each
other's personality.
Personalities have nothing to do with this. Facts.
> Let me know if you find this understanding satisfactory. CA
I've done these kinds of discussions many times. Either people clearly
understand what I want to say, or else it usu. ends in cresending
misunderstandings & often - not with you, I hope - in crescending insults. I
don't know whether it will be worth the trouble, but why not try?
Marc
Marc Verhaegen
> > > > why do you believe chimps don't have to store energy?? why can they
do with 10 times less fat tissue?
> That's quite a non sequitur even for a psychotic.
??
> But since he brought it up, humans, gorillas and orangutans all get
immensely fat when given an endless supply of food.
"Immensely fat"?? Idiot.
> Chimpanzees get fat but no where near like us
Yes. 10 times leaner. Why?? You're unable to answer that question.
> other apes. Chimps are the odd man out, not humans.
The sequence is probably Homo>Pongo>Gorilla>Pan. But humans are many times
fatter than the others. Why??
As usual much blabla. No answers.
Curious Amateur
>
>"Curious Amateur" <no_...@home.guv> wrote in message
>news:3_2R9.5389$8M3.9...@news20.bellglobal.com...
>
>> >> While being accused of being a "liar" is unpleasant,
>
>> >Yes, I shouldn't have said that, CA, I meant: misrepresenting my view is
>unfair. Marc
>
>> I was not "misrepresenting" it, Marc.
>
>You were, CA. Very much.
>
>> I was representing it to the best of my understanding.
>
>That may be correct...
>> If you want to clarify or correct that understanding,
>
>I've tried many times. In vain. I don't know why many PAs don't seem to
>understand what we are saying. I guess unconscious prejudices? Perhaps more
>important: the comparative evidence (what we see in other mammals) is much
>more important than certain (prejudiced IMO) interpretations of the fossil
>record.
Marc, if you are going to assume "unconscious prejudices" as a motive you are
going to run into brick walls till Hell freezes over. There are good people
with good reasons for not agreeing with you. You may still think they are
mistaken, but you are wrong to accuse them of prejudice.
>> you do not duck and run. If you don't care, fine. You're as entitled to
>spend your time as you wish as any. But don't expect acts of faith from me,
>Marc. I may be an amateur but I am certainly not stupid.
>
>OK, although I think you're often ill-informed.
I grant there are some things I do not know. There are some things you don't
know. No one knows it all, Marc.
I thought that's why a lot of us are here: to learn more.
>> I've noticed the previous article where you claim I have not one argument
>against the scenario you've quoted. If you wish to pursue this with me it
>will be with some understanding that we are debating the issue, not each
>other's personality.
>
>Personalities have nothing to do with this. Facts.
I hope we both remember that when we're discussing what is and is not a fact
with respect to the issue of AAT.
>> Let me know if you find this understanding satisfactory. CA
>
>I've done these kinds of discussions many times. Either people clearly
>understand what I want to say, or else it usu. ends in cresending
>misunderstandings & often - not with you, I hope - in crescending insults. I
>don't know whether it will be worth the trouble, but why not try?
Good.
CA
Michael Clark
Obviously too much of an argument for you, macro man. At
the first sign of an argument you run like a dog, turn, bark a few
times and then run again.
Curious Amateur
Argument 1: Soft Tissue
The above scenario talks about "greater breathing control (=preadaptation for
speech), .... reduction of fur, thicker fat tissues ..... high needs of
iodine, sodium, poly-unsaturated fatty acids etc."
None of the above leave a trace in the fossil record, thus none of the above
is supported by evidence in any homonid species aside from Homo sapiens
sapiens.
You have a continuum of time between our Last Common Ancestor with the Chimp,
and Hss:
LCA<-------------------------------------------------------------->Us
You place these transformations along with bipedality here:
LCA<---B-|------------------------------------------------------->Us
<B=Bipedality, |=soft tissue transformations>
Without evidence, these transformations can occur anywhere in this continuum,
such as here:
LCA<---B-------------------------------|------------------------->Us
Indeed, they may never have occurred together at all:
LCA<---B-|------|-----------------|--------------|--------------->Us
Without evidence, you cannot say when these changes occurred. But your theory
depends upon them all occurring with the development of bipedality. A lack of
evidence makes your claims much easier to dismiss.
Argument 2: Dextrous Hands
This is a subjective argument at best, as "dextrous" is a value judgment, not
a quantifiable measurement. The chimp is very dextrous when poling for
termites. Your arguments are weakened when you use value judgments like
"dextrous" that lack a well-accepted rating system.
Argument 3: Wading and Fur and Sunlight
First, humans are not hairless, but merely a short-haired hominid.
Pinnipedia, sea otters and polar bears all demonstrate an aquatic ability that
is not hindered by fur. No mechanism nor selective criteria has been proposed
to explain why the shortening of fur should be associated with a sea-side
habitat.
Furthermore, as anyone who has spent a day on the water at the beach can tell
you, water makes an excellent reflector of sunlight. You have dismissed the
argument that head hair protected early hominids from sunlight, yet your
argument not only has hominids exposing the length of their body to sunlight
reflected from water during the day, but you also have hominids swimming, thus
exposing the length of their body to the direct sun.
Seems to me your theory would expose hominids to far more sunlight over more
unprotected skin than a savannah habitat. Swimming and wading a tropical
seaside habitat would certainly expose the hominid to a good deal more UV rays
and heat. You've argued that the savannah is too hot for humans because they
lack the water-retaining adaptations needed to survive. Yet your scenario
would have humans sweating just as profusely at the beach. You've not
explained the difference between the two habitats with respect to
water-retention.
Argument 4: Thicker Fat Tissue
I know we just went through this, so I'll recap. In modern humans, SC fat
accumulates during times of over-indulgence (ie eating more calories than are
burnt). SC fat depletes during times of hunger (ie eating less calories than
are burnt). Thus SC fat is the body's method of ensuring there are always
enough calories to last through times of hunger. While the body cannot survive
very long without water, it is remarkably resilient to seasonal famine. Your
model does not propose a mechanism nor selective criteria for this use of SC
fat.
There is no evidence that SC fat makes for better aquatic abilities in humans.
-the lack of thickness fails to insulate the body against cold temperature
(too many 'holes' in the sc fat for nerves and the circulatory system etc to
effectively insulate the body).
-tropical waters are warm, no mechanism nor selective criteria driving the
development of SC fat is proposed for a seaside habitat.
-SC fat increases blood pressure and impedes the function of the organs and
limbs, accelerates the onset of fatigue.
Argument 5: Longer Legs
I confess to extrapolating from the above scenario by using statements you've
made, Marc. You associated shorter legs with knuckle-walking. In one quote,
you equated the two. Presumably your argument is that longer legs are
essential for bipedality.
I've pointed out that pygmies, young children, midgets and dwarves all have
shorter legs than most hominids we know of, and that all walk bipedally. I've
pointed out that it is the tilt of the hip, especially the bone that keeps the
thigh bone connected to the hip bone, that determines the type of locomotion.
If you wish to persist in asserting that shorter legs means knuckle-walking,
you will need to explain why pygmies, young children, dwarves and midgets are
not knuckle-walkers.
Argument 6: Greater Breathing Control
This is another subjective judgment. As I explained once before, if you choose
sperm whales as the standard rather than humans, you will see that our breath
control isn't much better than any other terrestrial creature. Furthermore,
there is very little way of comparing our control with that of other animals.
The only fair test is if the animals could understand the purpose of the test
and cooperate to the best of their ability, just as the human understands and
cooperates. Anything less would be unfair to the animals.
And while there are claims that we have a superior ability, it is not by any
means genetic or universal. The fact humans still drown demonstrates this.
Before bestowing an ability on the species, we should bear in mind just how
undeveloped it is in most of the species. Would we consider the red squirrel
"abroreal" if more than half couldn't climb trees without falling? Should we
consider humans "swimmers' when half don't know how to swim?
Argument 7: Where the Fossils are Found
You seem to take the fact that a lot of fossils are found in or near water as
proof that these creatures lived in the water. Fossil deposition is not proof
of preferred habitat.
Open water attracts all creatures, as all depend upon potable water for life.
Open water, especially during times of drought, attract a high percentage of
carnivores, as they are guaranteed to find their prey with the least amount of
exertion. Thus water-side fatality rates are much higher than away from water.
Due to all of the above, plus the fact that ancient river courses and lake
beds are easily identified, paleo-anthropologists tend to focus their efforts
in those areas. It is the most logical place to find all kinds of animals, as
all kinds eventually come to the water to drink and perhaps to die under the
claws of a predator.
Thus drawing conclusions about habitat based upon the fossil's deposition site
is fraught with the risk of misinterpretation.
As you can see, I have many arguments against your scenario. I have no
difficulty accepting that some hominids exploited sea-side habitats. I've no
difficulty accepting that they would have gained knowledge and experience over
time.
What I object to is the insistence that the emergence of bipedality was the
result of your scenario without any evidence in the fossil record to support
your contention that this is how bipedality arose, and given the arguments
I've listed above.
CA
Jim McGinn
His "considerable argument" involved his proposition
that bipedalism evolved as a tree climbing adaptation!
No joke.
Michael Clark
It won't work Jimmy. There may actually be one or two
readers of these groups who ~read~ the post in question.
Say, isn't that SBE I hear calling your name?
~J E E E M E E E~, where ~A R E~ you.....?
Marc Verhaegen
"Curious Amateur" <no_...@home.guv> wrote in message
> >> Marc has collected some facts which, superficially, support a theory of
an aquatic existence.
> >Not "aquatic", CA, I didn't say that, did I?
Did I?
> >Misrepresenting our ideas is not fair. Our scenario is this: In 1960
Alister Hardy ("Was Man more aquatic in the past?" New Scientist) described
how a sea-side lifestyle - incl. wading, swimming, collecting edible shells,
turtles, crabs, coconuts, seaweeds etc. - could explain many typically human
features that are absent in our nearest relatives the chimps, and that are
unexplained by savanna scenarios: reduction of climbing skills, very large
brain, greater breathing control (=preadaptation for speech), very dextrous
hands (stone tool use to open shells or nuts), reduction of fur, thicker fat
tissues, longer legs, more linear body build, high needs of iodine, sodium,
poly-unsaturated fatty acids etc. IMO, Hardy was only wrong in thinking
this seaside phase happened more than 10 Ma. Homo ergaster-erectus fossils
or tools are found in Israel, Algeria, E.Africa, Georgia, Java ca.1.8 Ma,
IOW, they spread along the Mediterranean & Indian Ocean coasts early
Pleistocene or earlier. Although most Pleistocene coasts are some 100 m
below the present sea level and it's mostly the inland Homo populations
(entering the continents along the rivers) that are represented in the
fossil and archeological record, Homo remains have frequently been found
amid shells, corals, barnacles etc., from 1.8 Ma (Mojokerto) to 0.1 Ma
(Eritrea), as well as on islands which could only be reached oversea (Flores
0.8 Ma). You don't have 1 argument that this scenario is wrong.
> Argument 1: Soft Tissue: The above scenario talks about "greater
breathing control (=preadaptation for speech), .... reduction of fur,
thicker fat tissues ..... high needs of iodine, sodium, poly-unsaturated
fatty acids etc." None of the above leave a trace in the fossil record,
This is where you are most wrong, CA. Our physiology & anatomy tell
something about us, no? Fossils tell only something about the fossils. The
exact relation to extanct hominids (=Pan,Homo,Gorilla) is largely uncertain.
We know we had ancestors, but we don't know whether fossils has descendants.
> thus none of the above is supported by evidence in any homonid species
aside from Homo sapiens sapiens.
So what?? This is about the scenario of *human* evolution, remember?
(And please try to use "hominid" for Pan+Homo+Gorilla+fossils vs "pongid"
for Pongo+fossils. It could make things a bit clearer to you.)
> You have a continuum of time between our Last Common Ancestor with the
Chimp,
> and Hss:
> LCA<-------------------------------------------------------------->Us
> You place these transformations along with bipedality here:
> LCA<---B-|------------------------------------------------------->Us
> <B=Bipedality, |=soft tissue transformations>
??
No, no!! Complete misrepresentation of our work. Please inform. In simple
terms: LCA (aquarboreal) evolved into Pan (more KWing) & Homo (originally
beach-comber).
> Without evidence, these transformations can occur anywhere in this
continuum,
> such as here:
> LCA<---B-------------------------------|------------------------->Us
> Indeed, they may never have occurred together at all:
> LCA<---B-|------|-----------------|--------------|--------------->Us
> Without evidence, you cannot say when these changes occurred. But your
theory
> depends upon them all occurring with the development of bipedality. A lack
of
> evidence makes your claims much easier to dismiss.
All occurring with...?? No, no, CA. Please read about our work, eg, our
paper "Aquarboreal ancestors?"
> Argument 2: Dextrous Hands This is a subjective argument at best, as
"dextrous" is a value judgment, not a quantifiable measurement. The chimp is
very dextrous when poling for termites. Your arguments are weakened when you
use value judgments like "dextrous" that lack a well-accepted rating system.
1) Area 4 for the hands is considerably larger in humans than in chimps. I
hope you don't believe chimps are more dextrous than humans?
2) Human can move the index & the other fingers independently. Chimps can't.
3) In our scenario, the LCA was already a very dextrous & tool-using.
4) In any case, our dexterity proves we never lived in the savanna: no
savanna mammal is very dextrous. Dextrous mammals are raccoons, chimps,
sea-otters, capuchins...
> Argument 3: Wading and Fur and Sunlight First, humans are not
hairless, but merely a short-haired hominid.
I said: "reduction of fur".
> Pinnipedia, sea otters and polar bears all demonstrate an aquatic ability
that is not hindered by fur.
We discussed this already & you didn't understand apparently. Why do you
believe only 1 factor can influence a feature?
> No mechanism nor selective criteria has been proposed to explain why the
shortening of fur should be associated with a sea-side habitat.
I said: "could explain". Savanna can't: shaving off the fur *enhances* body
temperature.
> Furthermore, as anyone who has spent a day on the water at the beach can
tell you, water makes an excellent reflector of sunlight. You have dismissed
the argument that head hair protected early hominids from sunlight, yet your
argument not only has hominids exposing the length of their body to sunlight
reflected from water during the day, but you also have hominids swimming,
thus exposing the length of their body to the direct sun.
Are you serious, CA? I said IMO human ancestors were beach-combers: they
climbed palm trees & dived for shells. In both these cases there's no
problem with sunlight. And if they were overheated they simply went into the
water. What is your problem??
> Seems to me your theory would expose hominids to far more sunlight over
more unprotected skin than a savannah habitat.
The skin is not the prime problem. Heat regulation is.
> Swimming and wading a tropical seaside habitat would certainly expose the
hominid to a good deal more UV rays and heat.
Why do you believe we didn't have a black skin?
> You've argued that the savannah is too hot for humans because they lack
the water-retaining adaptations needed to survive. Yet your scenario would
have humans sweating just as profusely at the beach. You've not explained
the difference between the two habitats with respect to water-retention.
?? Am I understanding you well??
- Savanna: no water, no salt.
- Beach: plenty of water, plenty of salt.
> Argument 4: Thicker Fat Tissue I know we just went through this, so
I'll recap. In modern humans, SC fat accumulates during times of
over-indulgence (ie eating more calories than are burnt). SC fat depletes
during times of hunger (ie eating less calories than are burnt). Thus SC fat
is the body's method of ensuring there are always enough calories to last
through times of hunger. While the body cannot survive very long without
water, it is remarkably resilient to seasonal famine. Your model does not
propose a mechanism nor selective criteria for this use of SC fat.
Why should I?? Why do you believe the possible function of SC fat as energy
depot rules out other functions?? And for the 100th time: why don't you
answer my question why chimps (who have as much hunger as humans have) don't
have thick SC fat??
> There is no evidence that SC fat makes for better aquatic abilities in
humans.
There's good evidence, eg, successful swimmers are on average fatter than
the winners of track events, and many long-distance swimmers are even
grossly fat (Pugh & Edholm 1955). The fat layer has been shown to be an
effective barrier against heat loss in water. A study of a fat Channel
swimmer revealed that when lying still in bath water at 18°C for more than 1
hour, he complained of no discomfort other than boredom; another subject
with much less SC fat complained of intense discomfort and showed a drastic
drop in rectal temperature after 15 minutes (Pugh & Edholm). Clearly, the
possession of the fat layer facilitates spending more time in the water. The
converse may also be true: it was found in a study of slightly obese women
that, without dietary restriction, an hour's daily walking or cycling
reduced body weight by 10 and 12 % resp. after 6 months, while a daily swim
caused a weight gain of 3 % over the same period (Gwinup 1987).
> -the lack of thickness fails to insulate the body against cold temperature
(too many 'holes' in the sc fat for nerves and the circulatory system etc to
effectively insulate the body).
CA, don't make up your own "facts", see, eg, the studies of Pugh and
Gwinnup.
> -tropical waters are warm, no mechanism nor selective criteria driving the
development of SC fat is proposed for a seaside habitat.
Again, don't make up your own facts. A bit serious please. The amount of our
SC fat seems to be ideal for tropical beaches: there are no problems with
over- or underheating when you spend the whole day in water of ca.26°C.
Fatter people have mre problems with overheating. Leaner ones with cooling.
> -SC fat increases blood pressure
Please, CA, no nonsense!! Evidence???
> and impedes the function of the organs and limbs, accelerates the onset of
fatigue.
Yes, on land. It's a heat trap in the savanna.
> Argument 5: Longer Legs - I confess to extrapolating from the above
scenario by using statements you've made, Marc. You associated shorter legs
with knuckle-walking.
You misunderstood. I said: KWing is unlikely to evolve in long-legged
hominids.
> In one quote, you equated the two.
You misread.
> Presumably your argument is that longer legs are essential for bipedality.
Yes, for wading (herons, flamingoes) & later for running (ostriches).
> I've pointed out that pygmies, young children, midgets and dwarves all
have shorter legs than most hominids we know of, and that all walk
bipedally. I've pointed out that it is the tilt of the hip, especially the
bone that keeps the thigh bone connected to the hip bone, that determines
the type of locomotion.
Bone that keeps the thigh bone connected to the hip bone??? Please,
CA.......
> If you wish to persist in asserting that shorter legs means
knuckle-walking
I never did.
> , you will need to explain why pygmies, young children, dwarves and
midgets are not knuckle-walkers.
:-D
> Argument 6: Greater Breathing Control - This is another subjective
judgment.
As i told yo many times, it is *not*: from one of my papers: Humans have a
very large representation of the oral muscles in Area 4 (see above), and
only in humans does damage of Area 4 produce muteness (Deacon 1997). Humans,
unlike chimpanzees and other primates, have an Area 4 representation of the
larynx and breathing musculature, have direct fibers connecting Area 4 to
the nucleus ambiguus (cortico-ambiguus connections), and can voluntarily
control the larynx muscles (nucleus ambiguus) and the breathing muscles
(brain stem).
>As I explained once before, if you choose sperm whales as the standard
rather than humans
Deep sigh. Again, you are not listening, CA! You are not fair! Our scenario
is not about sperm whales, but about early Homo along the Indian Ocean &
Med.sea!
> , you will see that our breath control isn't much better than any other
terrestrial creature. Furthermore, there is very little way of comparing our
control with that of other animals. The only fair test is if the animals
could understand the purpose of the test and cooperate to the best of their
ability, just as the human understands and cooperates. Anything less would
be unfair to the animals.
Sigh. Just place a banana on the bottom of a swimming pool and see whether
chimps are humans catch it first.
> And while there are claims that we have a superior ability, it is not by
any means genetic or universal. The fact humans still drown demonstrates
this.
All aquatic mammals drown ultimately. Point is: most land-based sports other
than walking & table tennis are up to 10 times more likely to lead to
fatalities than swimming, despite the additional danger of drowning incurred
by swimmers (Dolmans 1987).
> Before bestowing an ability on the species, we should bear in mind just
how undeveloped it is in most of the species. Would we consider the red
squirrel "abroreal" if more than half couldn't climb trees without falling?
Should we consider humans "swimmers' when half don't know how to swim?
In societies of Polynesian islanders, human children can swim before they
can walk.
> Argument 7: Where the Fossils are Found - You seem to take the fact that
a lot of fossils are found in or near water as proof that these creatures
lived in the water. Fossil deposition is not proof of preferred habitat.
No. I'm saying that the fact that nearly all hominid fossils are found in
water does not prove they did not spend part of their time in water. Got it?
> Open water attracts all creatures, as all depend upon potable water for
life. Open water, especially during times of drought, attract a high
percentage of carnivores, as they are guaranteed to find their prey with the
least amount of exertion. Thus water-side fatality rates are much higher
than away from water.
Possible. So what?
> Due to all of the above
IOW, nothing at all!!
> , plus the fact that ancient river courses and lake beds are easily
identified, paleo-anthropologists tend to focus their efforts in those
areas. It is the most logical place to find all kinds of animals, as all
kinds eventually come to the water to drink and perhaps to die under the
claws of a predator.
Possible. So what?
> Thus drawing conclusions about habitat based upon the fossil's deposition
site is fraught with the risk of misinterpretation.
Yes. So what?
> As you can see, I have many arguments against your scenario.
As you can see, you don't have 1 single argument against our scenario. Not
1, CA.
> I have no difficulty accepting that some hominids exploited sea-side
habitats. I've no difficulty accepting that they would have gained knowledge
and experience over time. What I object to is the insistence that the
emergence of bipedality was the result of your scenario
Bipedality is clearly the result of aquarborealism (short-legged
wading-climbing) & later beach-combing (long wading legs, linear body & legs
for swimming).
> without any evidence in the fossil record to support your contention that
this is how bipedality arose, and given the arguments I've listed above.
CA
The fossil evidence is essentially irrelevant, see above: it's about
fossils, not directly about our ancestors. Besides, it is in beautiful
accord to our scenario: H.ergaster-erectus did disperse over the Med. &
Ind.Ocean coasts in a remarkably short time, didn't they?
Marc Verhaegen
"Curious Amateur" <no_...@home.guv> wrote in message
> >> >> While being accused of being a "liar" is unpleasant,
> >> >Yes, I shouldn't have said that, CA, I meant: misrepresenting my view
is unfair. Marc
> >> I was not "misrepresenting" it, Marc.
> >You were, CA. Very much.
> >> I was representing it to the best of my understanding.
> >That may be correct...
> Whether you agree or not, that was what I thought I was doing.
Yes, I'm afraid so...
> >> If you want to clarify or correct that understanding,
> >I've tried many times. In vain. I don't know why many PAs don't seem to
understand what we are saying. I guess unconscious prejudices? Perhaps more
important: the comparative evidence (what we see in other mammals) is much
more important than certain (prejudiced IMO) interpretations of the fossil
record.
> Marc, if you are going to assume "unconscious prejudices" as a motive
Can motives be unconscious?
> you are going to run into brick walls till Hell freezes over. There are
good people with good reasons for not agreeing with you.
Good people, yes, but not forgood reasons.
> You may still think they are mistaken, but you are wrong to accuse them of
prejudice.
They are prejudiced as much as the inquisitors were in the Renaissance
although they themselves didn't call themselves prejudiced.
> >> you do not duck and run. If you don't care, fine. You're as entitled to
spend your time as you wish as any. But don't expect acts of faith from me,
Marc. I may be an amateur but I am certainly not stupid.
> >OK, although I think you're often ill-informed.
> I grant there are some things I do not know. There are some things you
don't know. No one knows it all, Marc.
It's obvious to me that I know many times moreabout human & ape evolution
than you do, CA. You hadn't even heard of Kenyanthropus...
> I thought that's why a lot of us are here: to learn more.
That's my problem: I haven't learnt much here.
> >> I've noticed the previous article where you claim I have not one
argument against the scenario you've quoted. If you wish to pursue this with
me it will be with some understanding that we are debating the issue, not
each other's personality.
> >Personalities have nothing to do with this. Facts.
> I hope we both remember that when we're discussing what is and is not a
fact with respect to the issue of AAT.
To the issue of my scenario, you mean? I have nothing to do with AAT, unless
it's the abbreviation of "aquarboreal ancestors theory" or "amphibious
ancestors theory".
> >> Let me know if you find this understanding satisfactory. CA
> >I've done these kinds of discussions many times. Either people clearly
understand what I want to say, or else it usu. ends in cresending
misunderstandings & often - not with you, I hope - in crescending insults. I
don't know whether it will be worth the trouble, but why not try?
> Good. CA
:-)
Marc
Jim McGinn
> > His "considerable argument" involved his proposition
> > that bipedalism evolved as a tree climbing adaptation!
> >
> > No joke.
>
> It won't work Jimmy. There may actually be one or two
> readers of these groups who ~read~ the post in question.
Hmmm. Well, maybe I was thinking of a different post
altogether. Remember that post, oh, about a day or
two ago or thereabouts, when you declared to the world
that in your educated opinion bipedalism was a tree
climbing adaptation, or something to that effect.
Remember?
Do you still stand by this?
Do you stand by anything?
Jim
Curious Amateur
Marc, can you point to a single fossil or group of fossils and point to
the evidence on the fossil that demonstrates the fossil once bore SC fat,
or reduced fur?
>Our physiology & anatomy tell something about us, no?
It tells us about Homo sapiens sapiens, yes.
>Fossils tell only something about the fossils.
Correct.
You asked me to argue with the quoted scenario, Marc. I agreed to do that. If
you wish to cite other papers feel free, but since you held the quoted
scenario up as representative of your position, I'll use the quoted scenario.
>> Argument 2: Dextrous Hands This is a subjective argument at best, as
>"dextrous" is a value judgment, not a quantifiable measurement. The chimp is
>very dextrous when poling for termites. Your arguments are weakened when you
>use value judgments like "dextrous" that lack a well-accepted rating system.
>
>1) Area 4 for the hands is considerably larger in humans than in chimps.
A lot of our anatomy is larger than the chimp's.
>I
>hope you don't believe chimps are more dextrous than humans?
I don't believe there is a well-accepted standard for comparison. Whether
chimps are more dextrous or not, and by how much depends upon the value
judgments and prejudices of the observer. Different observers are free to draw
different conclusions.
>2) Human can move the index & the other fingers independently. Chimps can't.
>3) In our scenario, the LCA was already a very dextrous & tool-using.
>4) In any case, our dexterity proves we never lived in the savanna: no
>savanna mammal is very dextrous. Dextrous mammals are raccoons, chimps,
>sea-otters, capuchins...
And baboons? They live in the savannah and are as dextrous as raccoons,
chimps, sea-otters and capuchins. So much for "our dexterity proves we never
lived in the savannah: no savannah mammal is very dextrous".
>> Argument 3: Wading and Fur and Sunlight First, humans are not
>hairless, but merely a short-haired hominid.
>
>I said: "reduction of fur".
Just making sure we understand each other.
>> Pinnipedia, sea otters and polar bears all demonstrate an aquatic ability
>that is not hindered by fur.
>
>We discussed this already & you didn't understand apparently. Why do you
>believe only 1 factor can influence a feature?
>
>> No mechanism nor selective criteria has been proposed to explain why the
>shortening of fur should be associated with a sea-side habitat.
>
>I said: "could explain". Savanna can't: shaving off the fur *enhances* body
>temperature.
No less so at the beach than in the savannah, Marc.
>> Furthermore, as anyone who has spent a day on the water at the beach can
>tell you, water makes an excellent reflector of sunlight. You have dismissed
>the argument that head hair protected early hominids from sunlight, yet your
>argument not only has hominids exposing the length of their body to sunlight
>reflected from water during the day, but you also have hominids swimming,
>thus exposing the length of their body to the direct sun.
>
>Are you serious, CA? I said IMO human ancestors were beach-combers: they
>climbed palm trees & dived for shells. In both these cases there's no
>problem with sunlight. And if they were overheated they simply went into the
>water. What is your problem??
1. Getting "into the water" exposes them to sunlight, their skin burns with
the UV rays, Marc. Even melanin will only hold back so much.
2. What prevents a savannah hominid from getting into the water, Marc?
>> Seems to me your theory would expose hominids to far more sunlight over
>more unprotected skin than a savannah habitat.
>
>The skin is not the prime problem. Heat regulation is.
And heat regulation is not controlled in part by outside factors like sunlight
and air temperature, humidity and other weather-related factors?
>> Swimming and wading a tropical seaside habitat would certainly expose the
>hominid to a good deal more UV rays and heat.
>
>Why do you believe we didn't have a black skin?
Melanin is not an immunity, Marc.
>> You've argued that the savannah is too hot for humans because they lack
>the water-retaining adaptations needed to survive. Yet your scenario would
>have humans sweating just as profusely at the beach. You've not explained
>the difference between the two habitats with respect to water-retention.
>
>?? Am I understanding you well??
>- Savanna: no water, no salt.
>- Beach: plenty of water, plenty of salt.
Since when did the savannah lose its water, Marc? I've seen the watering holes
in the savannah. There are rivers and lakes in the savannah. Are you
suggesting all those wildebeest and lions _never_ drink water from a lake or
river? And how would they survive without salt?
As for the beach, lots of water and lots of salt really means lots of salt
water, which is undrinkable by human standards.
>
>
>> Argument 4: Thicker Fat Tissue I know we just went through this, so
>I'll recap. In modern humans, SC fat accumulates during times of
>over-indulgence (ie eating more calories than are burnt). SC fat depletes
>during times of hunger (ie eating less calories than are burnt). Thus SC fat
>is the body's method of ensuring there are always enough calories to last
>through times of hunger. While the body cannot survive very long without
>water, it is remarkably resilient to seasonal famine. Your model does not
>propose a mechanism nor selective criteria for this use of SC fat.
>
>Why should I?? Why do you believe the possible function of SC fat as energy
>depot rules out other functions?? And for the 100th time: why don't you
>answer my question why chimps (who have as much hunger as humans have) don't
>have thick SC fat??
Okay, Marc, I'll answer that question (as I've done more than once already)
Chimps are not faced with seasonal deprivations to the degree humans must
face. Chimp populations do not outstrip their resources and tropical forests
do not experience seasonal variations to the degree of temperate climates.
Thus, tropical forests do not run out of food to the degree of less hospitable
locations.
The selective criteria would be entering an area that experiences seasonal
deprivations. Those without SC fat starve, while those with SC fat survive
till the next food-producing season.
This suggests SC fat did not occur in the ancestral line till our ancestors
left the forests.
As for your statement "Why should I?? Why do you believe the possible function
of SC fat as energy depot rules out other functions?? And for the 100th time:
why don't you answer my question why chimps (who have as much hunger as humans
have) don't have thick SC fat??"
It's obvious you are unwilling to discuss this issue, Marc. There is no point
in wasting my time on you when your answer is "Why should I??".
Thank you for trying.
CA
Curious Amateur
>
>"Curious Amateur" <no_...@home.guv> wrote in message
>news:ndnR9.6236$8n5.1...@news20.bellglobal.com...
>
>- Savanna: no water, no salt.
snip
>
>
>> Argument 4: Thicker Fat Tissue I know we just went through this, so
>I'll recap. In modern humans, SC fat accumulates during times of
>over-indulgence (ie eating more calories than are burnt). SC fat depletes
>during times of hunger (ie eating less calories than are burnt). Thus SC fat
>is the body's method of ensuring there are always enough calories to last
>through times of hunger. While the body cannot survive very long without
>water, it is remarkably resilient to seasonal famine. Your model does not
>propose a mechanism nor selective criteria for this use of SC fat.
>
>Why should I??
snip
>The fossil evidence is essentially irrelevant
Obviously you are not interested in seriously discussing the issue, Marc. I
won't waste any more of my time or yours trying to discuss it with you.
Thanks for trying.
CA
Marc Verhaegen
> "Jim McGinn" <jimm...@yahoo.com> wrote in message
> news:ac6a5059.03010...@posting.google.com...
> > "Marc Verhaegen" <fa20...@skynet.be> wrote in message
> news:<3e1552ad$0$29637$ba62...@news.skynet.be>...
> > > > Sure --and this was snipped from a ~long~ post where I put forward a
considerable argument.
> > > put forward a considerable argument?? ridiculous
> > His "considerable argument" involved his proposition that bipedalism
evolved as a tree climbing adaptation! No joke.
:-D Incredible: the only non-arboreal primate is exactly the only one
that is bipedal... Clark has nothing to say. His only "arguments" are
insults.
Marc
Marc Verhaegen
"Curious Amateur" <no_...@home.guv> wrote in message
> >Did I?
Did I?
You don't understand. I'll try to be very simple:
- humans ahave a lot of SC fat,
- chimps have almost no SC fat,
- why the difference??
Idem reduced fur.
Etc.
Etc.
You are incapable of explaining why human & chimps differ in these
instances.
> >Our physiology & anatomy tell something about us, no?
> It tells us about Homo sapiens sapiens, yes.
Exactly.
> >Fossils tell only something about the fossils.
> Correct.
> >The exact relation to extanct hominids (=Pan,Homo,Gorilla) is largely
uncertain. We know we had ancestors, but we don't know whether fossils has
descendants.
No answer.
> >> thus none of the above is supported by evidence in any homonid species
aside from Homo sapiens sapiens.
> >So what?? This is about the scenario of *human* evolution, remember?
(And please try to use "hominid" for Pan+Homo+Gorilla+fossils vs "pongid"
for Pongo+fossils. It could make things a bit clearer to you.)
No answer.
> >> You have a continuum of time between our Last Common Ancestor with the
Chimp, and Hss:
> >> LCA<-------------------------------------------------------------->Us
> >> You place these transformations along with bipedality here:
> >> LCA<---B-|------------------------------------------------------->Us
> >> <B=Bipedality, |=soft tissue transformations>
> >?? No, no!! Complete misrepresentation of our work. Please inform. In
simple terms: LCA (aquarboreal) evolved into Pan (more KWing) & Homo
(originally beach-comber).
No answer;
> >> Without evidence, these transformations can occur anywhere in this
continuum, such as here:
> >> LCA<---B-------------------------------|------------------------->Us
> >> Indeed, they may never have occurred together at all:
> >> LCA<---B-|------|-----------------|--------------|--------------->Us
> >> Without evidence, you cannot say when these changes occurred. But your
theory depends upon them all occurring with the development of bipedality.
Not at all.
> A lack of evidence makes your claims much easier to dismiss.
Not at all.
> >All occurring with...?? No, no, CA. Please read about our work, eg, our
paper "Aquarboreal ancestors?"
> You asked me to argue with the quoted scenario, Marc. I agreed to do that.
If you wish to cite other papers feel free, but since you held the quoted
scenario up as representative of your position, I'll use the quoted
scenario.
You are not using it. You are using your own interpretations of it.
> >> Argument 2: Dextrous Hands This is a subjective argument at best, as
"dextrous" is a value judgment, not a quantifiable measurement. The chimp is
very dextrous when poling for termites. Your arguments are weakened when you
use value judgments like "dextrous" that lack a well-accepted rating system.
> >1) Area 4 for the hands is considerably larger in humans than in chimps.
> A lot of our anatomy is larger than the chimp's.
Relatively, CA. Relatively. Willingly misunderstanding what I'm saying?
> >I hope you don't believe chimps are more dextrous than humans?
> I don't believe there is a well-accepted standard for comparison. Whether
chimps are more dextrous or not, and by how much depends upon the value
judgments and prejudices of the observer. Different observers are free to
draw different conclusions.
Please give 1 observer who says chimps are more dextrous than humans.
> >2) Human can move the index & the other fingers independently. Chimps
can't. 3) In our scenario, the LCA was already a very dextrous &
tool-using. 4) In any case, our dexterity proves we never lived in the
savanna: no savanna mammal is very dextrous. Dextrous mammals are raccoons,
chimps, sea-otters, capuchins...
> And baboons? They live in the savannah and are as dextrous as raccoons,
chimps, sea-otters and capuchins
Assertions without evidence.
>. So much for "our dexterity proves we never lived in the savannah: no
savannah mammal is very dextrous".
Do you claim savanna baboons are as dextrous as humans are??
> >> Argument 3: Wading and Fur and Sunlight First, humans are not
hairless, but merely a short-haired hominid.
> >I said: "reduction of fur".
> Just making sure we understand each other.
Don't you understand "reduction of fur"??
> >> Pinnipedia, sea otters and polar bears all demonstrate an aquatic
ability that is not hindered by fur.
> >We discussed this already & you didn't understand apparently. Why do you
believe only 1 factor can influence a feature?
No answer.
> >> No mechanism nor selective criteria has been proposed to explain why
the shortening of fur should be associated with a sea-side habitat.
> >I said: "could explain". Savanna can't: shaving off the fur *enhances*
body temperature.
> No less so at the beach than in the savannah, Marc.
Why not?
- Fur reduction has been proven to be maladaptive in the savanna.
- Fur reductions is a frequent feature of mammals that spend a lot of time
in water.
> >> Furthermore, as anyone who has spent a day on the water at the beach
can tell you, water makes an excellent reflector of sunlight. You have
dismissed the argument that head hair protected early hominids from
sunlight, yet your argument not only has hominids exposing the length of
their body to sunlight reflected from water during the day, but you also
have hominids swimming, thus exposing the length of their body to the direct
sun.
> >Are you serious, CA? I said IMO human ancestors were beach-combers: they
climbed palm trees & dived for shells. In both these cases there's no
problem with sunlight. And if they were overheated they simply went into the
water. What is your problem??
> 1. Getting "into the water" exposes them to sunlight, their skin burns
with the UV rays, Marc. Even melanin will only hold back so much.
So what?? Do you believe our beach dwelling ancestors had more problems with
sunlight than African people have?? Why do you believe that??
> 2. What prevents a savannah hominid from getting into the water, Marc?
Donet you think there's more water at the beach than in the savanna??
> >> Seems to me your theory would expose hominids to far more sunlight over
more unprotected skin than a savannah habitat.
> >The skin is not the prime problem. Heat regulation is.
> And heat regulation is not controlled in part by outside factors like
sunlight and air temperature, humidity and other weather-related factors?
Please, try to know what you want to talk about: UV or heat regulation?
> >> Swimming and wading a tropical seaside habitat would certainly expose
the hominid to a good deal more UV rays and heat.
> >Why do you believe we didn't have a black skin?
> Melanin is not an immunity, Marc.
Why do you believe that our beach dwelling ancestors had more problems with
UV than Afr.people have??
> >> You've argued that the savannah is too hot for humans because they lack
the water-retaining adaptations needed to survive. Yet your scenario would
have humans sweating just as profusely at the beach. You've not explained
the difference between the two habitats with respect to water-retention.
> >?? Am I understanding you well?? - Savanna: no water, no salt. - Beach:
plenty of water, plenty of salt.
> Since when did the savannah lose its water, Marc? I've seen the watering
holes in the savannah. There are rivers and lakes in the savannah. Are you
suggesting all those wildebeest and lions _never_ drink water from a lake or
river? And how would they survive without salt?
Savanna mammals need _less_ water than forest or beach animals. Humans are
exactly the opposite: we need lots of water.
> As for the beach, lots of water and lots of salt really means lots of salt
water, which is undrinkable by human standards.
It is not. It has been shown (Bombard) that when you gradually drink sea
water many times a day in small quantities you can survive on a diet of
fish. Besides, apparently you're not talking about our sea-side scenario:
why do you believe they didn't eat coconuts, figs etc.?
> >> Argument 4: Thicker Fat Tissue I know we just went through this, so
I'll recap. In modern humans, SC fat accumulates during times of
over-indulgence (ie eating more calories than are burnt). SC fat depletes
during times of hunger (ie eating less calories than are burnt). Thus SC fat
is the body's method of ensuring there are always enough calories to last
through times of hunger. While the body cannot survive very long without
water, it is remarkably resilient to seasonal famine. Your model does not
propose a mechanism nor selective criteria for this use of SC fat.
> >Why should I?? Why do you believe the possible function of SC fat as
energy depot rules out other functions??
No answer.
> >And for the 100th time: why don't you answer my question why chimps (who
have as much hunger as humans have) don't have thick SC fat??
> Okay, Marc, I'll answer that question (as I've done more than once
already) Chimps are not faced with seasonal deprivations to the degree
humans must face.
?? Why not?? Why do you believe that? Because you want to prove human
ancestors lived in the savanna??
> Chimp populations do not outstrip their resources
Why do you believe that??
> and tropical forests do not experience seasonal variations to the degree
of temperate climates.
Why do you think tropical people (much SC fat) are not sapiens?? and/or why
savanna baboons (few SC fat) live in forests??
> Thus, tropical forests do not run out of food to the degree of less
hospitable locations.
Why don't savanna baboons have much SC fat??
> The selective criteria would be entering an area that experiences seasonal
deprivations. Those without SC fat starve, while those with SC fat survive
till the next food-producing season.
No just-so stories, CA. I know that is what you believe. Creationists
believe other things, but you have no better arguments than they have.
> This suggests SC fat did not occur in the ancestral line till our
ancestors left the forests.
And what about baboons that left the forests??
> As for your statement "Why should I?? Why do you believe the possible
function of SC fat as energy depot rules out other functions?? And for the
100th time: why don't you answer my question why chimps (who have as much
hunger as humans have) don't have thick SC fat??" It's obvious you are
unwilling to discuss this issue, Marc. There is no point in wasting my time
on you when your answer is "Why should I??". Thank you for trying.
CA
Unfortunately I can not thank you, CA. You have wasted my time. You don't
have 1 single argument.
Michael Clark
That's right, macro man --just insults. That must be why you never
respond to them. CA beat you up pretty badly today. I suppose we'll
never see any substantive rebuttal to those "insults", either. As for your
characterization of humans as "non-arboreal", you'll have to concede that
our ancestors were not always so. To do so, however, would leave you
open to the possibility that bipedalism may ~not~ have arose as a function
of wading. And we just can't have that, can we......
Where'd you pick up your most recent convert? If you want to throw
him back, I hear that they miss him over at SBE.
> Marc
Richard Wagler
Jim McGinn wrote:
Inform a bit - to quote the inimitable Marc Verhaeg*e*n
The locomotion of the LCA is the critical factor that
all would like to see revealed. However the best
conjectures link bipedalism with a cautious, vertical
climber and here we see significant amounts of what
amounts to bipedal behaviour - in terms of body
orientation - in arboreal species such as orang-utans.
So, yes Jim, in a certain sense bipedalism is a tree
climbing adaptation in as much as deriving bipedalism
from a cautious vertical climber may not be that big
a stretch. Locomotion in primates is a major topic and
a very large literature is available on the topic.Check
into it. Fascinating stuff.
Rick Wagler
Michael Clark
> > "Michael Clark" <bit...@spammer.com> wrote
> > > Bipedalism arose in the trees. After a certain threshold
> > > in body size is reached, it becomes most efficient for a
> > > large-bodied, arboreal primate to either move beneath
> > > branches or on ~top~ of them (bipedally!).
> >
> "Jim McGinn" <jimm...@yahoo.com> wrote in message
> > It is true that bipedalism arose in a species that
> > occupied trees. But it's pretty whacko to say that
> > bipedalism arose in trees. And who knows where
> > you're getting this "threshold," BS.
Yes, I stand by it. Get thee hence to the nearest zoological garden.
Patiently observe the troop of white-cheeked gibbons. Record the
percentage of time that these gentle creatures move through their
environment --both brachiating and ~bipedally~ across the tops
of horizontal and near horizontal branches. Walk to the next
enclosure and do the same with the chimps. Now crawl back into
your car and travel to the nearest playground. Observe the children
playing on the "monkey bars". Do these creatures display a tendency
to support their weight in a vertical fashion while hanging on to
adjacent "branches" with the hands and arms? This is pretty standard
*current anthro*, Jimmy. I'm surprised that you're not familiar with
it (well, I'm not surprised at all).
From http://www.pbs.org/wnet/secrets/case_firsthuman/clues.html
"But Orrorin comes from a time when East Africa was still heavily forested.
So how could our earliest ancestors have learned to walk on two feet, and why?
Robin Crompton, of the University of Liverpool, has a solution. He believes
that Orangutans can show us how we learned to walk -- by balancing and
walking within the branches of the trees at times upright on two feet.
This could explain how Orrorin and Orrorin's ancestors learned to walk six or
more million years ago in a forested environment. They would actually stride
along in the trees, as well as walk from tree to tree. This idea and the discovery
of Orrorin is revolutionising our understanding of how we came to be."
So it seems that while you're calling me "whacko", you're going to have to
call Crompton "whacko" as well.
> Do you stand by anything?
One thing at a time, Jimmy, one thing at a time. Say, are you ever
going to relate the sad tale of McGinn's exhile from SBE? Probably
not, huh?
> Jim
Curious Amateur
<bit...@spammer.com> wrote:
snip (and removing the other two newsgroups from the distribution list)
>From http://www.pbs.org/wnet/secrets/case_firsthuman/clues.html
>
>"But Orrorin comes from a time when East Africa was still heavily forested.
>So how could our earliest ancestors have learned to walk on two feet, and why?
>Robin Crompton, of the University of Liverpool, has a solution. He believes
>that Orangutans can show us how we learned to walk -- by balancing and
>walking within the branches of the trees at times upright on two feet.
>This could explain how Orrorin and Orrorin's ancestors learned to walk six or
>more million years ago in a forested environment. They would actually stride
>along in the trees, as well as walk from tree to tree. This idea and the
> discovery
>of Orrorin is revolutionising our understanding of how we came to be."
Any explanation for choosing this method of locomotion, Michael? Chimps (and
presumably the LCA) have managed trees for quite some time without bipedalism,
so what benefit would be derived from the above scenario?
CA
Marc Verhaegen
> > :-D Incredible: the only non-arboreal primate is exactly the only one
that is bipedal... Clark has nothing to say. His only "arguments" are
insults.
> That's right, macro man --just insults. That must be why you never
respond to them. CA beat you up pretty badly today.
:-D
Marc Verhaegen
"Richard Wagler" <taxi...@shaw.ca> wrote in message
news:3E171C05...@shaw.ca...
> The locomotion of the LCA is the critical factor that all would like to
see revealed.
Don't you know yet?? Aquarboreal, of course. What else??
Michael Clark
I think it has something to do w/ body size. Monkeys seem to do quite nicely as
quadrupeds --running along the tops of branches, and because they are smaller, they
seem to be able to reach the extremities of these branches more easily than the
larger
bodied apes. Once your body size reaches a certain threshold (and I don't pretend
to know what that would be) an ape would have a tendency to seek stability by
reaching out to other branches --with their hands and arms. Getting out to the
periphery is, of course, the objective. It is the smaller branches that hold the
resources and promise some measure of safety and security --both from predators
and the harrasment of your fellows.
Of course, I have no
time machine and would not presume to cast any of this in stone but I think it is
pretty much what Crompton is saying. Chimps move through the trees in this same
manner. They are overhead climbers, brachiators, and will ~stand~ on large branches
while they steady themselves by grasping other branches. I don't think they can be
described as "running along branches" --at least in the same sense as the smaller
monkeys. White-cheeked gibbons (a troop of which I am lucky enough to live
very close to) will do the same to an even greater degree. Watching these gibbons
~run bipedally~ along the tops of branches is a sight to see. So, no, I don't see
the "savanna" or the "swamp" as the crucible for bipedalism. I think there is a much
easier explanation --one that is staring us right in the face. Naturally, once this
critical skill is ingrained in your behavioral repetoire, then exploiting it to move
on to terra firma (and the exploitation of additional resources that ground
foraging enables) is a virtual certainty.
Thoughts?
> CA
Curious Amateur
>"Curious Amateur" <no_...@home.guv> wrote in message
>news:0QIR9.8521$rr1.1...@news20.bellglobal.com...
>> In article <v1e9g9n...@corp.supernews.com>, "Michael Clark"
>> <bit...@spammer.com> wrote:
>>
>> snip (and removing the other two newsgroups from the distribution list)
>>
>> >From http://www.pbs.org/wnet/secrets/case_firsthuman/clues.html
>> >
A few.
1. The heavier the animal, the stronger the branch needs to be to support the
weight. This does not trend towards getting out to the "periphery" as weight
increases. If the best food is out on the periphery (and I believe it is in
most cases) then we'd expect the animal to trend smaller, so as to take
advantage of smaller, weaker branches and actually get to the fruit.
2. As you point out, chimps are doing quite well in the trees, no apparent
pressure for them to develop bipedality. I see no reason for speciation (ie a
new food resource unattainable by knuckle-walking apes or quadruped monkeys
but only available to rapidly-developing bipedal hominids)
3. Balance. The larger the animal, the more difficult the balance (centre of
gravity moved higher from the feet increases top-heaviness). Add to this the
idea of altricial infants requiring a hand and arm to hold them (yes, that's
an assumption, they could have fur and chimp-like infants with functional
grasping appendages) and you have a problem balancing new mothers.
Finally, it seems the purpose of the theory is to explain bipedality from the
point of view of the end product, as opposed to how it fits into the survival
strategy of the animal in question. Assuming incremental changes, each
increment must contribute to the success of the organism. Starting from a
chimp-like knuckle-walker, how does the first increment improve the chances of
survival of the organism and promote its genes into the next generation?
As an aside, I propose we refer to this as the "Tarzan Theory" for obvious
reasons ;-)
CA