Re: An alternative to ST and AAT

Paul Crowley (
Fri, 06 Dec 96 12:33:35 GMT

In article <5825e0$> "Gerrit Hanenburg" writes:

> (Paul Crowley) wrote:
> >It is clear from their anatomy that there was no great
> >selective pressure on the Australopithecines to develop an
> >efficient walking technique, or that other aspects of their
> >niche inhibited it. IOW it's unlikely that Lucy walked a lot.
> >Getting around in the most effective way was not one of her
> >priorities. Roh's assumption is commonly made because it
> >is the obvious one: "early hominids became bipedal to get
> >about more efficiently than when they were quadrupedal".
> >But it is not borne out by a study of their anatomy.
> You are exaggerating the inefficiency of Lucy's bipedalism.

I was primarily talking about the switch-over from
quadrupedalism to bipedalism - over 1 Myr before Lucy.
She would have been quite advanced by comparison with the
first hominids, whose bipedalism must necessarily have been
less effective at ordinary progression than chimps'

> Nowhere in the literature is it stated that Lucy's bipedalism was less
> efficient than chimpanzee quadrupedalism.

This is hardly surprising. "Efficiency", whatever it means,
can only be measured on some ghastly machine like a treadmill,
and Lucy is not available. Even if she was, it would be hard
to know how to set up a meaningful experiment. A better word
might be "effective". Of course, "effectiveness" depends on
the habitat; but if it was open woodland, then the chimp
would win nearly every time.

> Contrary to what you say it is clear from her anatomy that there had
> been selection in favor of greater efficiency.

I have not suggested otherwise.

> Christine Berge only states that Lucy's bipedalism was likely less
> efficient than that of modern humans but not that there had been no
> selection for more efficiency.

All I'm saying is that she must not have done a lot of
walking. She wasn't designed for it. So what was she
designed for?