Re: AAT Theory

Muttiah ((no email))
22 Sep 1995 14:14:10 GMT (J. Moore) wrote:
>On the other hand, in an aquatic change with sufficient selection
>pressure to change the structure of the pelvis, we would expect to
>also see, for instance, extensive limb-shortening, as we see in
>aquatic mammals where selection pressure has been sufficient to
>change the pelvis (such as pinnipeds, sirenia, and cetaceans).
>So the AAT is forced to suggest that in this one case, the aquatic
>environment somehow forced *just this one change*, one that can't be
>distinguished from a land-based transition, and somehow didn't
>force others, such as limb-shortening, that would also be expected.

That's if the AATers are suggesting that the homonids did live in
the aquatic evironment all the time. Now if these guys (not the AATers)
spent some of their time on land and some in water then it seems a little
more believeable (I think most of the time when a mammal hits
the sea it tends to stay there for a while -- take the very nice theory
on pakisades for example).