Re: bipedalism and AAH
Pat Dooley (patdooley@aol.com)
8 May 1995 21:47:51 -0400
j#d#.moore@canrem.com (J. Moore) writes:
>Um> In <1995May4.151403.2084@arl.mil> Troy Kelley <tkelley@hel4.brl.mil>
>Um> writes:
>
> << deletions>>
>
>Actually, as Phil Nichols has pointed out (repeatedly!) in this
>newsgroup, actual tests with chimpanzees has demonstrated that even for
>those knuckle-walking apes, bipedalism is no less efficient a mode of
>getting around. So the entire above argument is meaningless; the
>question has been answered by scientific experimentation.
>
How do these experiments measure efficiency? It may be that for
foraging, chimpanzee style bipedalism (which is very different
from true human bipealism) may be as energy efficient as
quadrupedalism. I tend to doubt that becaus evolution maximises
efficiency and we don't observe chimpanzees favoring bipedalism over
their usual modes of foraging locomotion.
Another important measure is speed, as in, how quckly can a
chimpamzee get to a tree if threatened by a predator? The fact of the
the matter is that in such circumstances, chimpanzees do not favor
bipedalism.
<< More deletions>>
>
>Um> Shoreline habitats have their own share of predators, particularly
with
>Um> the extremely aquatic lifestyle often proposed by AAH
>Um> proponents...sharks etc.
>
Strawman argument. Sharks have been around for hundreds of millions
of years and thousands of terrestrial species have made the transition to
an
aquatic existence during thatr period. Obviously sharks did not stop
proto-whales, proto-dugings, or proto-penguins making the transition from
land to water. Even today, when millions of human beings take to the
sea, the shark kill rate is about on a par with lightening strikes.
>And crocodiles. Of course one of the AAH adaptive scenarios has AAs
>outswimming sharks; but since sharks swim at over 20 mph, and the
>fastest Olympic athletes can only manage a little over 5 mph
>(5.1048 mph in the 1992 Olympic Games 50 meters to be exact), that
>seems mighty unlikely.
Aboriginals in the Northern territory and North Queensland spend a lot of
time gathering food in aquatic environmnts. They share that environment
with the salt water crocodile, a beast that makes any African crocodile
look
like a mere salamander. So far as I know, Aboriginals swim at about the
same speed as the rest of humanity and a lot slower than a saltie.
The more likely predation was the AA on crocodile eggs rather than
crocodiles
on AA.
>
<<deletions>>
>Um> >>>Again, why would they walk bipedially when it is such an
>Um> >>>inefficient means of transportation?
>
>I do hope we aren't going to see this incorrect, unsupported, and
>disproven claim again ;-(
You will, until you address the issues of disadvantageous intermediates
and explain why only one rather sluggish mammal species evolved
bipedalism. (if you don't believe sluggish, try out-running any savannah
predator. I'd love to watch!)
>
>
>In any event, Caroline Pond (who is acknowledged as a leading edge
>expert on fat and who Morgan cites as support of her views even though
>Pond's work directly and explicitly contradicts the AAH) has shown
>that human fat distribution is like terirestrial primates:
Pond does nothing to explain the wide disparity between human fat levels
and the primate norm.
So far as I can see, her contradictions are little more than assertions.
>
>"The sparse data on the 'natural' distribution and abundance of adipose
>tissue in primates show that the basic anatomy of human adipose tissue
>is similiar to that of terrestrial monkeys, and so was probably
>inherited directly from their primate ancestors."
Of course it was inherited from their primate ancestors. It wasn't going
to be
inherited from their feline ancestors :-).
>
>"Anatomical, ecological and biochemical information provides no evidence
>that the distribution of adipose tissue in modern humans has evolved as
>an adaptation to thermal insulation, as required by the Aquatic Ape
>Theory, or as protection from mechanical damage."
>
Oh, so perhaps Pond can tell us why it did evolve, along with all the
other human oddities.
Pat Dooley
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