Re: Bipedalism and other factors

David L Burkhead (
3 Jul 1995 01:32:56 GMT

In article <3t7b72$> (Pat Dooley) writes:
>Your points might have some validity if the proposed aquatic ape was an
>ocean going swimmer. It is far more likely to have been a shore line
>forager, rarely venturing into deep water. In such a case, it only has to
>make it to the shallows to evade a shark or crocodile.

It would have to make it to shallows too shallow for shark or
crocodile. For the shark, that would be, at best, no more than knee
deep and even that is uncertain. While sharks don't generally attack
prey in water that shallow they _can_. And crocodiles can follow your
fleeing pre-humans right up onto the shore if they wanted to. The
thing is, they'd not _have_ to. They are so much faster in the water
than humans that from the time the pre-humans would know they are
there, and the time they struck, a pre-human would only go a couple of
feet. The same for sharks in waist deep water. They are _so_ much
faster than humans in water that you don't have _time_ to get to the shallows.

In _real_ shark attacks (as opposed to the ones in movies) the
first sign that anyone has that the shark is even there is often when
the attackee notices that his _arm_ (or leg) is gone!

>That option is not available to an ape trying to outrun a leopard.

Still clinging to that "treeless, waterless savanna"? Fleeing
for the trees is comparable to fleeing for the shallows--and the race
is _much_ more even. Go look at my numbers again. The fastest human
swimmer there ever was is less than half as fast, compared to typical
swimming predators, as an average runner against the fastest land

And go look at how chimpanzees _actually_ deal with predators
like leopards. It's _not_, in general, by fleeing. They do, at least
on occassion, band together to _drive off_, or _kill_, the leopard.
There is no reason at all why our putative ancestors could not have
done the same thing.

The idea that an aquatic environment is, somehow, safer from
predators than a savannah environment (not the mythical "treeless,
waterless savannah" but a real one) is patently false.

David L. Burkhead

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