Re: bipedalism
ndr102@psuvm.psu.edu
Sun, 16 Apr 1995 15:39:34 EDT
In article <3moieo$r5b@rebecca.albany.edu>, pn8886@csc.albany.edu (Phil
Nicholls) says:
>
>seriously. We have fossil evidence showing that hominids moved
>moved from the forest to savannah.
>
>We have no evidence that they moved into the water. There is
>nothing in the AAH that can be tested and until this changes
>it remains just another just so story.
Well, we can look for hominid fossils in the Danakil Alps dating
from when the region was an island or several islands. Even a
find would not absolutely prove that the creatures in question were
semi-aquatic, or that they and not cousins of theirs on the mainland
were our ancestors, but it would make the AAH at least as respectable
as alternative explanations of bipedalism, etc.
>>> Do we know for certain what the prime mover toward
>>> bipedalism was? No, we don't know for certain. We
>>> probably will never know for certain.
>
>> Defeatist!
>
>Fine. Tell me how it is possible to know for certain why
>hominids became bipedal.
I have to agree with Mr. Nicholls on this one. We can't prove a
hypothesis in paleoanthropology the way we can prove a hypothesis
in geometry. The question is which idea bleeds less from Occam's
Razor. And here I agree with Mrs. Morgan. The aquatic hypothesis
explains quite a few anomalies, and I'm still waiting for a compelling
counterargument.
>>> We can generate hypotheses and test them. Wheeler did
>>> that. Rodman and McHenry did that. Prost did that. You
>>> haven't done that. All we get are more books rehashing the
>>> same just-so story about convergent evolution.
>
>> "Just So story" is not an argument. It is just a sneer. I
>> use the same sources, the same references, the same rules of
>> logic as the orthodox theorists do. The books are not
>> re-hashes; each one brings new facts to bear on the argument.
>
>Stephen Jay Gould used the term "just so story" to describe
>many kinds of evolutionary explanations -- adaptionists
>explanations. Everything is not necessarily adaptive and
>those adaptionist explanations that cannot be tested are just
>so stories. A logical argument is worthless if you cannot use
>it to make predictions and generate testable hypotheses.
>Until the AAH does this it will remain a just so story.
This argument can be turned around: Are alternatives to the AAH
really testable? One can test whether bipedalism aids in keeping
cool on the savannah, but even if the answer is affirmative, one cannot
prove that that's why our ancestors became bipedal. One can test
whether bipedalism aids in keeping one's nose out of water (yes,
obviously), but that does not prove that our ancestors became bipedal
for that reason.
>As for none of the criticisms of the AAH making it into print,
>I must say that I am amazed. Certainly you couldn't have
>missed Adrenne Zihlman's critique of the AAH in OCEANS
>magazine a few years back. Then there is that book _Aquatic
>Ape: Fact or Fiction_ that folks mention on this topic so often.
>Finally, if you reviewed those articles on sweating and
>hairlessness in the Journal of human Evolution that I cited in
>our exchange on sweating I think you will see that each one
>discussed the AAH -- Wheeler gave it almost two whole pages in
>a 20 page article.
Zihlman in OCEANS? I'll try to find it if I can catch up with my
own dissertation in Materials. As to _Aquatic Ape: Fact or Fiction_,
the libraries here don't have it, and it's out of print.
I am glad to see the question discussed and references given. As
I've said, I think Elaine Morgan has a case, but I'm not an expert,
and I do know that in other fields, ideas which sound good to some
laymen are nonsense if you really know the subject. So I want to
see what anthropologists have to say against the AAH.
Nicholas Rosen
Standard disclaimers apply.
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