Re: AAT Theory

David Froehlich (
Sun, 1 Oct 1995 19:18:40 -0500

On 1 Oct 1995, H. M. Hubey wrote:

> 1) whether mammals did not indeed have been aquatic. AFter all
> giving birth in warm water seems even easier than dropping them
> on land. The baby would have come out and wouldn't have to start
> breating until it floated to the surface. It's already used to
> "holding its breath". If this happened at the time when much
> of earth was under water, then the water would have been warmer
> since the ice caps would have been melted. And the mammals
> could have had body temperatures approximating water temperature
> at the time. Besides, much of the food would/could have been
> in the water by then. Even now, sea life is abundant.

Are you now advocating that all mammals have an aquatic ancestor? If so
I would actually agree with you. They are called fishes. However, the
last common ancestor of all mammals was certainly a fully terrestrial
amniote tetrapod. Aquatic mammals include pinnipeds (derived from fully
terrestrial carnivores), mustellids (otters, again fully terrestrial
carnivores), sirenians (derived from fully terrestrial ungulate stock),
whales (derived from fully terrestrial ungulate stock). Note that all
marine mammals are derived from terrestrial ancestors. The fossil record
is clear!!!! The lacunae that AAS attempts to fill is a relatively short
period of time in the late Miocene. All maine mammals took a long time
to become aquatic, much longer than the available gap. AAS gets around
this fact by producing fuzzy and untestable statements about how any
changes would be indistinguishable from terrestrially derived
Just because there is no monolithic theory about how this
terrestrial change occured does not mean that AAS is a viable
alternative. The only reason that it is still an issue on this list is
that there are a few adherents who refuse to let it die. Have you ever
noticed that most of the pro AAS folks are not professional physical
anthropologists? This is not because these pro AAS folks are a repressed
minority. It is because most professional physical anthrologists have
better things to do.

> 2) Apes could have been aquatic and could have developed
> long digits (and maybe webbing) as a result of the aquatic
> environment. That could explain the whole grasping development
> to begin with. After all, without it you still have to explain
> how something like a dog would begint grasp and develop talents
> to use tools. It would be a lot easier in water; notice polar
> bears and sea otters.

Grasping is a plesiomorphic (ie primitive feature for archontans(shrews
primates, bats etc) and possibly all mammals). You cannot argue that a
feature already present in the ancestors was then developed due to an
aquatic phase. Otters and bears do not grasp like we do. Primates have
an apposable thumb, carnivores have the pollex bound with the other
digits (Please read Gould's Panda's Thumb).

In general, the level and type of arguements that go on in this forum
under the pro AAS banner remind me very strongly of the methods used by
Duane Gish and ilk. Pro AAS tends to argue from an unasailable premise
that is by its very nature untestable and then throw the fuzzy science
epithet around at anybody who does not agree (I admit I am also at fault
for this).

As a final comment, to make AAS a viable scientific arguement it must
provide a testable series of propositions that are not equally or better
explained by pre existing ideas. The very statement that AAS stands
alone and there are no other ideas about the development of bipedalism is
a gross misrepresentation of the scientific literature. A scientific
speculation or hypothesis must be more than just sexy.

Flame away.

David J. Froehlich Phone: 512-471-6088
Vertebrate Paleontology Laboratory Fax: 512-471-5973
J.J. Pickle Research Campus
The University of Texas, Austin, Texas 78712