Re: AAT reply from Elaine Morgan

WIlliam C. Wilson (
3 Jan 1995 09:41:46 GMT

<< deletions>>
> For example, except for the very largest, they are all hairy.
> The physiological explanation for that is that fur facilitates
> efficient sweating, provides insulation during cold savannah
> nights, and protects against solar radiation.

Excuse me , the last I heard canids and felids don't sweat, the release
excess heat thru panting or by not building it up in the firtst place
(animal "seistas"). As to the other reasons I suspect that alternate
explanations not requiring an aquatic stage could be found (comunal
sleeping arrangements to deal with cold nights, vertical (bipedal) stance
to reduce area and intensity of radiation affects, etc.)

> since water is a scarce resource and water holes are dangerous places.
> Every savannah animal at risk from predators can run faster than any human
> and they can do it almost from birth. Baboons and Patas monkeys are
> far faster than humans and retain the ability to climb rapidly.

And every animal that is aquatic (or semi-aquatic?) is to my knowledge
active and coordinated from birth (or from nest/den leaving). The extended
natal non-coordinated (ie not fully mobile) status of human (and
anthropod) babies argues for a nonaquatic development.

> You persist in labelling these modes of locomotion as bipedal.
> Bipedalism in the human sense involved major anatomical changes
> that are not seen in any other ape species.

They may not be bipedal in the sense that modern humans and birds
can be considered bipedal but the the center of gravity shows that
the majority of weight is fairly clearly on the hind limbs, not
equally distributed between hind and fore limbs as in true quadrapeds.
If I was forced to give them a label it would probably be something like
semi-bipedal or rear dominant quadrapedal. In either case how does
body support style argue for or against bipedal state, most aquatic
and semi aquatic animals (other than fish) are quadrapedal not bipedal.

> According to Richard Leakey and Roger Lewin "the evolutionary
> shift from quadrupedalism to bipedalism would have required an
> extensive remodelling of the ape's bone and muscle architecture
> and of the overall proportion in the lower half of the body.

WHo is saying otherwise?

> About all you€ve demonstrated so far is that apes, under the
> right evolutionary pressure, would be more likely to develop
> bipedalism than pure quadrupeds. Your post about Bonobos
> was quite instructive.

And it would be a lot easier to do if you had to walk/run all
the time rather than dogpaddle. since all the occasional bipeds
seem to wade in shallows and dogpaddle in deeper waters an aquatic
ape must have been a shallow water wader who seldom ventured into
deep water. this strikes me as the most dangerous not the safest
water zone since it is subject to both land and marine predators.

> Humans, as you well know, have a 99/1 distribution of eccrine/acropine
> glands that puts them well off the ape norm. If they had gone
> directly from the forest to the savannah with your 50/50 distribution,
> then 100 million years of mammalian evolutionsays that
> humans would have evolved acropine sweating if they
> needed to improve their heat dissipation mechanism.

For those of us who haven't studied skin glands in detail, what are
the differences between these 2 types of glands?

> its adaptations when the hunter disappears. Lets try another example that
> fits within your 2 million year time frame.

I really dont care about time frames, if you argue slow gradual evolution
the time frame is too short; if you argue rapid puctuated evolution
with a 2 million year aquatic phase then why didn't some other
animal rapidly adapt to the open savannah exclusively. Such an
animal would almost certainly have been better adapted than one
that had spent the last 2 million years in and around water.
And from 3.5 MYA I think even you would agree that hominids
have been primarily land /savannah dwellers.