Re: An alternative to ST and AAT

Susan S. Chin (susansf@netcom.com)
Mon, 11 Nov 1996 00:18:45 GMT

Paul Crowley (Paul@crowleyp.demon.co.uk) wrote:
: In article <32822fc8.12140237@news.leiden.nl.net>
: G.Hanenburg@inter.nl.net "Gerrit Hanenburg" writes:

: > Paul@crowleyp.demon.co.uk (Paul Crowley) wrote:
: >
: > >This raises a very interesting point. For some 2.5 million years
: > >(until about 2.5 mya) hominids could not stride and probably could
: > >not run; if they could, they certainly did not do it well. The
: > >australopithecines had short legs, long arms and no waist.

I'm really puzzled by this supposed inability of Australopithecines to
stride and run. Does this mean that due to their "short legs and long
arms" they were inefficient, waddling bipeds? How do you account for the
Laetoli footprints then? 3.7myo and fully bipedal stride, there is even
an arch in the foot, so not only did these hominids stride, they did so
with shock absorbers developed in the foot.

Also, I'm curious what is meant by Australopithecines have "no waist"?
Anatomically, the afarensis pelvis and its changes would indicate
otherwise.

: > >So why did they maintain this very strange morphology for so long?
: It is very strange for a bipedal animal; we're constantly told
: that the whole point of bipedalism was to enable a more effective
: progression on the ground.

Maybe it depends on where you learn your Anthropology, I don't recall
being told bipedalism evolved as a more effective form of locomotion. If
anyhting else, it is incredibly inefficient and possibly dangerous for
early hominids compared to quadrupedal locomotion. So there must have
been some pretty strong selective factors which made some early apes
stand up in a predominantly quadruped world. What those factors are, I
haven't a clue, though it seems alot of others do... which is good.

: Why was waddling selected for anyway?

: Paul.

As far as I know, the only instances of waddling that I know of is
in pregnant women and people who've overindulged at those all you can eat
buffets :) <not that I would know from personal experience of course>

Susan

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                                             susansf@netcom.com