Bipedalism - the other view

Troy Kelley (
Fri, 20 Oct 1995 17:24:19 GMT

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.

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.

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?
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

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.

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.