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Re: AAH update (was: Bipedalism and other factors and AAT)
Alex Duncan (aduncan@mail.utexas.edu)
23 Jun 1995 18:41:48 GMT
Alex Duncan
Dept. of Anthropology
University of Texas at Austin
Austin, TX 78712-1086
512-471-4206
aduncan@mail.utexas.edu
I can't help but chime in here.
The fact that hominids are capable of maintaining a constant
temperature in a heat-stressing environment is evidence that we are well
adapted to that environment. There is often more than a single solution
to a given problem, and simply because we don't use the same mechanisms
that bovids and equids do to deal with a hot open ecosystem doesn't mean
we're not well-adapted to it.
In fact, it might be suggested that the hominid adaptation to
living in a heat-stressing environment is superior to that of other
critters that are out there. We can travel much longer distances in a
given time than most other savannah-dwelling critters, and there are many
accounts of humans "walking their prey to exhaustion" in the hot sun. A
bovid may be able to run fast for a short distance on a hot day, but it
can't run long. Ambush predation is one way to deal with this, and
"exhaustion predation" is another. Yes, there is a cost -- we can't
stray too far from the water hole (unless we use tools: canteen, gourd,
skin water-bag).
Another point -- there really isn't a lot of evidence that early
hominids were living strictly in a savannah environment. The faunal
remains associated w/ A. ramidus are definitely suggestive of a more
closed habitat, and much of the evidence for A. afarensis and A.
africanus also point to life in a mosaic habitat in which a number of
different microhabitats were available. A. boisei is found in
depositional environments that are indicative of wetter habitats than the
co-eval H. erectus. In fact, its not until the appearance of H. erectus
that we see good evidence for "good" adaptation to open habitats
(human-like intermembral index, 1.8 m stature, thin "equatorial" body
build).
And finally, a comment on leopards -- yes, they climb trees, but
they don't hunt in trees (their prey are almost exclusively terrestrial
animals).
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