Re: Crowley's post to sci.bio.evolution
Alex Duncan (aduncan@mail.utexas.edu)
16 Nov 1995 13:40:26 GMT
In article <48dft1$gt@news.cc.ucf.edu> Thomas Clarke,
clarke@acme.ist.ucf.edu writes:
>Not so. There were non-bipedal miocene apes.
>There were fully bipedal Australopithecines. There is nothing
>in between. There is no documented evolutionary history of bipedalism.
"Fully bipedal" -- what do you mean by that? A very good argument could
be made (has been made) that australopithecines represent an intermediate
state (one of many) between human locomotion and "ape" locomotion
(whatever that may turn out to be).
>> The
>> fossil record provides no evidence that bipedalism evolved in an aquatic
>> habitat.
>
>Nor does it provide evidence that it evolved in any other
>particular habitat.
I think that we could argue that we have very good evidence that at least
one stage of bipedalism evolved in the habitats australopithecines lived
in. And, the evidence is pretty good that the earliest
australopithecines evolved in mosaic habitats with a mixture of forest,
woodland, brush and grassland habitat. However (to be fair), the
australopithecines represent a reasonably advanced stage in the evolution
of bipedalism, and our ideas about earlier habitats must necessarily be a
little shakier. Currently the best thing going would be to suggest that
earlier stages of bipedalism evolved in habitats "intermediate" between
the ones the australopithecines lived in, and the ones that earlier
potential ancestors such as Kenyapithecus, Dryopithecus and
Ouranopithecus lived in. It is very suggestive (and contrary to what P
Crowley would have us believe -- it confirmed what everyone suspected)
that A. ramidus remains were found in contexts which indicate more closed
habitats than those for later australopiths.
Alex Duncan
Dept. of Anthropology
University of Texas at Austin
Austin, TX 78712-1086
512-471-4206
aduncan@mail.utexas.edu
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