Re: AAT Theory
Paul Crowley (Paul@crowleyp.demon.co.uk)
Sun, 24 Sep 95 19:48:06 GMT
In article <60.2789.7295.0N1F58CD@canrem.com>
j#d#.moore@canrem.com "J. Moore" writes:
In article <60.2789.7295.0N1F58CD@canrem.com>
j#d#.moore@canrem.com "J. Moore" writes:
> since crocodiles are, and have been for millions of years, the
> most ubiquitous large predator throughout most of Africa, and
> certainly in all the areas, and habitats, that the AAT has at
> various times postulated for their transitional population,
> infesting all the fresh and salt waters of eastern Africa (even in
> waterholes in the desert of Chad!), there were no "non-infested"
> waters available for these purported aquatic hominids.
Jim is right to focus on predation as a vital issue. But he has said
nothing about nocturnal predation; this matters as both crocs and lions
are mainly nocturnal. Even gorillas go upstairs to sleep. What did
transitional/early-bipedal hominids do? If you say they used trees,
then it's hard to see how they could have become bipedal so quickly.
Jim is wrong about "no non-infested waters". (1) Crocs are reptiles and
need heat: at some point you can move 50 miles north or 100 feet higher
and you won't find them; (2) they can't climb: so the hominids could have
inhabited lakes in hilly areas. The East African lakes: Edward, George,
and Kivu are croc-free, possibly because crocs can't climb waterfalls,
but more probably because the lakes aren't warm enough. Their equivalents
5mya could easily provide an environment suitable for an aquatic ape.
Most AAT'ers seem to prefer a hot marine one. The hominids could have
inhabited rocky coasts with little sloping access to the sea. In any
case, a heavily-crevassed littoral rock shelf could have provided
numerous predator-free havens. Marine crocs only seem to be a danger in
swamps or when they have good cover; they are hardly a threat in clear
waters. To get safety at night the hominids could have slept on boulder
islands (steep-sided if necessary).
Predation was probably a problem, but I'm sure we're bound to get our
assessment of it completely wrong. It's far too easy to exagerate the
dangers and misunderstand how a local population copes with it. Given
how dangerous sharks are supposed to be, it's hard to believe that
millions swim daily and unconcernedly from tropical beaches.
Our extremely weak sense of smell seems a most unlikely attribute in a
continuously terrestrial animal which was both heavily predated and a
predator. Any explanation for this, Jim?
Paul.
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