Re: Asleep at the idiot box

On Sat, 13 May 2006 16:53:23 -0700, Evan Kirshenbaum
<kirshenbaum@xxxxxxxxxx> wrote:

Al in Dallas <alfargnoli@xxxxxxxxx> writes:

On Thu, 11 May 2006 18:33:57 -0700, Evan Kirshenbaum
<kirshenbaum@xxxxxxxxxx> wrote:

Salvatore Volatile <me@xxxxxxxxxxx> writes:

Evan Kirshenbaum wrote:
In time, the glands started appearing all over the body in
various concentrations and were exapted into an enormously poorly
designed[1] temperature regulation device. Why? Well, that's
another story, and I've only heard one convincing explanation,
and it's considered highly unorthodox, so perhaps we'd best not
go there.

Erk, *please* tell me you're not still a subscriber to the Aquatic
Ape Theory. That's Kool-Aid, man.

Sorry. I haven't seen a better analysis, or even a good listing of
the shortcomings of the theory.

The version I read claimed to explain *both* bipedalism and
hairlessness. Nowadays, we know that the original bipedal apes
seemed to be otherwise completely chimplike. That is, bipedalism was
the first step from the common ancestor to Homo sapiens. So, how has
the theory been modified? Were their two aquatic periods, one that
stood our ancestors up and a second that made us hairless?

The attraction of the aquatic theory is that it's a single hypothesis
that provides a plausible explanation for a large number of anatomical
distinctions between humans and other primates and other savannah
animals in general (among them, hairlessness, bipedalism, breathing
control, eccrine sweating, excessive fat layer, acne), including
differences that weren't known at the time the theory was formed, such
as the so-called "baboon marker", a genetic marker that all African
primates but humans have and which indicates that at a critical period
humans "weren't in Africa", as far as contact with baboons is
concerned. But while one such period is, to my mind, plausible, two
would not be.

Well, Dawkins seems to think the apes evolved in Asia, with some
returning to Africa, including non-bipedal gorillas and chimpanzees.
Can you point me to more information about the "baboon marker"?

But I'm unfamiliar with the assertion you made. Could you give me a
citation?

I thought I was referring to the entire Australopithecus genus, but
I'm sure you're familiar with Lucy, et al. I just finished the
*Ancestor's Tale* a few weeks ago. (March is just a few weeks ago,
right?)

For one thing, I'm not sure how you could tell from fossil
evidence that an animal wasn't hairless. For another, I'd be curious
as to where these proto-humans were found. If they were in the
Danakil region, they might merely be transitional forms during the
development of the isolated population. (During which isolation it
would be quite plausible for one trait to evolve before another.) Or,
of course, there may have been more than one population of
semi-aquatic apes (in one place or several), with the "original
bipedal apes" not being our ancestors but having some, but not all, of
the adaptations that our ancestors did.

Why do most anthropologists reject it?

I've never been able to figure this out. They never seem to say just
what's wrong with it. Dawkins and de Waal both both describe it as an
intriguing hypothesis, but both eventually wave it away with
essentially "but alas it's unlikely to be true". Others seem to be
more inclined to ridicule it, but mostly, as far as I can tell,
because (1) the chief proponent isn't herself a credentialed scientist
and (2) the cool scientists say that it's ridiculous.

Yep, those seem to be the main two reasons AFAIK, too.

They never seem
to say what there objections are, and I harbor the sneaking suspicion
that this is because they're afraid that if they do somebody will ask
them just what *their* explanation is for the fact that we appear to
have so many features that are unheard of in a savannah-dwelling
animal[1] and are either reasonably common in aquatic mammals or which
are more easily explained (either by benefit or by ease of
acquisition) in aquatic animals.

[1] With the execption of a single animal, the elephant, which has a
snorkel for a nose.

--
Al in St. Lou
.

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