Re: AAT Theory

Phillip Bigelow (
12 Sep 1995 17:50:39 -0700 (J. Moore) writes:

Troy Kelly attempted:
>Tk> Jim, I see you are still at it.
>Tk> This skeletal argument reminds me of my "Polar Bear Challenge" which I
>Tk> posted some months ago, perhaps even a year ago. This was long before
>Tk> Jim graced us with his fanatical anti-AAT diatribes.

J. Moore ( succeeded at noting that:
>I'm surprised to see you no longer on the AAT side, Troy -- why
>else would you be aching to provide the anti-AAT case of the polar
>bear. But you're right when you say that the case of the polar
>bear is indeed a grave challenge to the AAT. The challenge, of
>course, results from the fact that the polar bear seems not to have
>any of the changes the AAT insists are a natural and necessary
>consequence of aquatic life. No predominate bipedalism or "pelvis
>straightening", the pattern of fat deposits is the same as
>terrestrial bears, no hairlessness, no descended larnyx, no
>ventral-ventral sex.

>Yes, we can all agree with you that the "polar bear challenge" is
>a difficult problem for the proponents of the AAT, and one which
>they haven't addressed. I commend you for bringing it up; now
>are you going to address it?

Well put, Jim.
It should also be noted that, from a "comparative anatomy" view, there is
nothing in the polar bear's anatomy (skeletal or soft tissue) that supports
an "aquatic" or "semi-aquatic" adaptation. Now.. since Ms. Morgan stresses
comparative anatomy as her "evidence" for an aquatic past for hominids, the
polar bear analogy shows that "comparative anatomy-as-evidence" has severe
limitations, particularly when it is used to suggest behavioral adaptations.
Your right: the polar bear analogy should be a "wake-up call" for those who
attempt to read too much into comparative anatomy.
(as an aside, we paleontologists would classify the polar bear as a
terrestrial arctoid carnivore...and we would be right from a biological
point-of-view. The fact that the polar bear has aquatic habits is more of
an interesting anecdote, but hardly worth a yawn from us-types!) :-)