Re: AAT Questions...
Pat Dooley (patdooley@aol.com)
5 Jul 1995 10:24:14 -0400
Pat Dooley wrote:
[many snips]
>>Our nearest relatives have no such system - chimps and gorillas don't
>>sweat, no matter how hot it gets or how hard they work.
>>[many more snips]
>I know this is just a small part of the original post, but this is what
>caught my attention. Are you sure chimps and gorillas don't sweat? I was
>under the impression they did. If they don't sweat, do they have some
>comparable mechanism?
They don't sweat, period. When they are under heat stress they pant, like
dogs. Oddly, humans don't pant to lose heat unless sweating won't work,
like in a hot bath.
>While I'm at it, here's another question. I haven't read about the AAT;
I've
>only followed some of the posts here. Why did the aquatic hominid return
to
>land? The AAT supporters argue that bipedalism is a terrible trait for
>savannah life. So then why did the aquatic hominids move there, and why
did
>they survive?
Bipedalism was fine once it had fully evolved and the possesor had the
size, social structure and tools to make up for its short-range
disadvantages.
The Afar desert, site of the oldest hominid fossils, was once an inland
sea.
It formed about 7 million years ago (about the time of the
human/chimpanzee
split) and slowly evaporated over the next few million years. The AAT
proponents suggest that some forest apes were isolated on islands in
that inland sea, and forced by the dessication of their environment to
become somewhat aquatic. When the sea became too salty to sustain
life (like the Red Sea today) emerged they were forced
back to a terrestrial mode of existence. They likely followed rivers south
into the African mainland.
The fossil evidence from the relevant period (7-4 mya) is still missing
but the location of some of the earliest fossils is suggestive.
>Dave B
Pat Dooley
Dave B.
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