Re: Bipedalism - the other view

Phil Nicholls (
Sun, 22 Oct 1995 16:59:30 GMT

Troy Kelley <> graced us with the following words:

>I am a bit sick of trying to defend AAT, not because I don't think it is
>worth while theory, but only because, as the opponents to AAT have found
>out, it is much easier to tear something down than to build it up.
>So I would like to do some tearing of my own.

Translation: misery loves company.

>I would like to hear some of the accepted theories on bipedalism from
>those anti-AATers, and we'll see if there aren't some holes in those
>theories; perhaps many more holes than there are in the AAT. I have
>heard people constantly shoot at AAT, and yet they never offer up any
>credible theories as an opposing viewpoint. Now is the chance.

Troy, if you want to know some of the other ideas that have been
floated to explain the origin of bipedalism why don't you go to the
library. I have now read two of Morgan's books. Do you mean to tell
me that you have been defending the AAS without any real grasp of what
professional anthropologists have to say except for what you read

>Therefore, if bipedalism evolved, in part, to reduce heat stress, by
>reducing the amount of surface area exposed to the sun, as some people
>have posted, why did it evolve in an animal (Australopithecus) which
>lived in a shaded (mosaic) environment? Or at least in an environment
>that had plenty of access to shade? In other words, why would an animal
>adopt such an unusual adaptation to heat stress, one that has not been
>adopted by any other animals in similar situations, when all the animal
>would really have to do is head for a shady area under a tree?

Please see the following:

Wheeler, P. (1984) The evolution of bipedality and the loss of
functional body hair in hominids. J. Human Evolution 12:91-98.

Also try the following:

Hewes, G.W. (1961) Food transport and the origin of hominid
bipedalism. American Anthropologists 63: 687-710.

Hewes, G.W. (1984) Hominid bipedalism: independent evidenc for the
food-carrying theory. Science 146:416-418.

Lovejoy, C.O. (1981) The origin of man. Science 211:341-350.

McHenry, H. (1982) The pattern of human evolution: studies on
bipedalism, mastication and encephalization. Annual Review of
Anthropology 11: 151-173.

Napier, J. (1963) The locomotor functions of hominids IN
Classifcation and Human Evolution, S. Washburn, ED.

Napier, J. (1964) The evolution of bipedal walking in hominids.
Archives de Biologie 75: 673-708

Shipman, P. (1984) Scavenger hunt Natural History 93:20-27

Sinclair, A.R.E, M.D. Leakey and M. Norton-Griffths (1986) Migration
and hominid bipedalism. Nature 307-308.

Rodman, P.S. and H.M. McHenry (1980) Energetics and the origin of
hominid bipedalism. American Joural of Physical Anthropology

Washburn, S.L. (1960) Tools and human evolution Scientific American
203(9): 63-75.

Zihlman, A. and L. Brunker (1978) Hominid bipedalism: Then and Now.
Yearbook of Physical Anthropology 22:132-162

What you will get from the above is a good overview of various ideas
on the evolution of bipedalism AND critiques of these ideas. You will
get a good history of these ideas, much better than what you get from
Morgan's books. Some are little better than the AAS and none are what
I would call a theory. Some of them, specifically Wheeler and
Rodman/McHenry, are good hypotheses in that they have been tested.

What you will not find is anything called the "savannah theory."

>Jim, I know what you are going to say. Chimps and apes are at least
>partially bipedal. That doesn't wash, I am talking about completely

Bipedalism begins as part of the locomotor behavior of most anthropoid
primates. It has become a locomotor speciality in hominids just as
brachiation has become a locomotor speciality in gibbons and
knuckle-walking has become a locomotor speciality in chimpanzees and

>If this is not "the" accepted theory to bipedalism, I invite all the
>anti-AATers to please post their own theory of bipedalism, so we can see
>if it is at least as sound as the AAT theory.

Or what, the AAS wins by default?

>Oh.. one more thing.. It would be nice if "the" theory of bipedalism was
>as parsimonious as AAT in that it could account for hairlessness as
>well... but I guess that would be too much to ask.

Sorry Troy, but it don't work that way.

Get back to us when you've caught up on your reading.

Phil Nicholls
"To ask a question you must first know most of the answer"
-Robert Sheckley