Re: The scientific method and the AAH
Phillip Bigelow (firstname.lastname@example.org)
Wed, 7 Dec 1994 06:54:59 GMT
email@example.com (Pat Dooley) writes:
>Hairlessness a simple mutation? So how come we can just about divide
>mammals into three categories:
>1. Hairy land dwellers.
>2. Large hairless aquatic and wallowing mammals.
>3. Small oily haired, multi-coated semi-aquatic mammals.
And, or course, to be _accurate_, you should have added to your list the
"Hairy water-loving primates", which include the proboscus monkey, and the
Japanese monkey. Both go into the water, and both have abundant hair.
As has been stated earlier on this thread, Lucy was a small-sized hominid,
with a "slight" stature (according to people who have described this
species, such as Don Johanson). As such, any ancestor of A. afarensis would
be at least as slight-of-build, and probably smaller (chimpanzee-sized would
be a good guess). When one scales down our ancestors to a large surface
area-to-small volume ratio, as all small animals have, the problem of keeping
warm when wet becomes important. Large animals such as hippos have a large mass
so they maintain body heat and therefore don't need hair for insulation.
Pat, you've got to face an annoying fact:
***There is no animal alive today that has the small stature of A.
afarensis, or smaller, that is semi-aquatic and has no hair***
The animal, if it ever existed, would have constant hypothermia, even in
a warm climate. Period. Small, oily-haired, multi-coated semi-aquatic
mammals make good evolutionary sense. Small, naked semi-aquatic primates
would be too busy shivering to evolve, even if they were all on a tropical
desert island as Morgan has dreamnt up. The only physiologically-possible
adaptation that a small naked primate could make in order avoid the
inevitable consequences of hypothermia would be to get large...I mean
_large_, so that heat could be retained while in the water. Even humans
today are not massive enough to retain heat for any length of time, even in
warm water. Hypothermia is often reported in ship-wreck survivors that have
spent time in the warm waters of the Carabbean Sea.
I wish that Morgan's supporters would, instead of just blindly quoting her
pet theories from her book, instead start looking into
the physiological problems that Morgan's theories create. I suggest a
good primer-course on the concepts of endothermy, ectothermy, and mass
homoiothermy. There are many good texts out there.