Alex Duncan (
27 Jun 1995 17:38:44 GMT

This crocodile thing is getting a little tedious, and distracting from
the real point. Those who say early hominids spent a lot of time in the
water to avoid predators must admit that the aquatic African environment
also had predators, which would have posed similar problems for early
hominids as terrestrial predators. There is also the problem of
water-borne parasites.
The real point is this: There are no human adaptations that
support the AAT that aren't more plausibly explained by a model that
suggests we evolved from a small ape that may have spent the majority of
its time in the trees (the ones I've seen have been refuted by J. Moore).
Most of our anatomy is essentially identical to the anatomies of chimps
and gorillas, neither one of which is known to spend much time in the
water (I'm not saying they never enter the water -- just not often).
What I've seen of this discussion so far reminds of the
creationist style of argument. The supporters of the AAT have yet to
offer a plausible list of human features that would be adaptive in an
aquatic environment. Rather, they seem to spending most of their time
pointing out small problems with a straw man model of hominid evolution
that suggest that one day *boom* pre-hominids found themselves on the
savanna and suddenly developed bipedalism, tool use, big brains, etc.
Very few paleoanthropologists working today would support such a model.
We do not know as much about the evolution of hominid features as
we would like to. However, every year brings an expanded fossil record
and better paleoecological data that we try to fit into our models.
There are still (and alway will be) unanswerable questions. Our
dissatisfaction with current models shouldn't lead to far fetched
hypotheses that are not supported by either modern human anatomy and
behavior, or by the fossil record. It is important that most of the
hominid fossils we know of occur in terrestrial rather than lacustrine
depositional contexts. Yes, they are usually found with indications that
there was water near by, but they're rarely found in contexts that
suggest they were IN the water. In the few instances where hominid
fossils are found in lacustrine sediments, they're usually associated
with other terrestrial fauna, and the most plausible explanation is that
they washed in from upstream.

Alex Duncan
Dept. of Anthropology
University of Texas at Austin
Austin, TX 78712-1086