Re: bipedalism and AAH

Kevyn Loren Winkless (
8 May 1995 19:04:38 GMT

In <3oh3il$> (Phil Nicholls) writes:

>In article <3ogj13$>,
>Kevyn Loren Winkless <> wrote:

>>Yes, this is the case, but this also assumes that the common ancestor was
>>a knucklewalker. My explanation above covers the possibility (which
>>seems to have been repeatedly asserted by AAH proponents) that this
>>ancestor was as yet just a generalized primate, unspecialized for either
>>knucklewalking or bipedalism. The question I was replying to was: why
>>would an unspecialized primate develop toward bipedalism rather than
>>quadrapedalism (or something to that effect)? Anyway, we're saying the
>>same thing (I think you might have confused what I wrote with inclusions
>>from previous posts).

>Sorry, no. That is, the studies which I have cited repeatedly disproves
>the assumption that bipedalism is less efficient that quadrupedalism at
>least when it comes to walking. The measurments were taken on chimpanzees
>because they are living and it is somewhat difficult to take these
>readings on fossils.

>My point is that the common ancestor was not a knuckle-walker as has
>been fairly well demonstrated, that it was most likely an arboreal
>ape (clearly indicated by Lucy's limb bone proportions and curved
>toes) and very likely a suspensory feeder. The latter adapation
>would predispose it to be a biped when it moved on the round, much
>the same as gibbons and spider monkeys who are modern suspensory
>feeders. This is not to imply that humans are descended from either
>spider monkeys or gibbons.

Even though you seem to be certain you disagree with me, thanks for
making my point: that it doesn't really matter whether or not bipedalism
is less efficient in certain species of knucklewalkers since the common
ancestor was not a knucklewalker.

Not having actually seen the research
you cite, I can't comment on it (by the way, where is it published?), but
nonetheless I feel that the entire argument over relative efficiency of
bipedalism in chimpanzees is a red herring created by the fact that
chimpanzees are our closest living relative...people tend to assume that
they have to explain why we're not chimpanzees, and so do intellectual
gymnastics which were unnecessary in the first place.

Anyway...perhaps I didn't make myself clear the first time I posted on
this thread: I was saying much the same thing you were, phil. I don't
know where the wires got crossed, but I did not say (anywhere) that
bipedalism was less efficient than quadrapedalism; in fact I specifically
stated that they were equally efficient.

Sorry if this sounds a bit touchy, but I was getting frustrated. Hope my
stance is clearer now...;)

...Kevyn Winkless

"...I drank WHAT!!?" - Socrates