Re: Dissecting the Aquatic Ape: Bipedalism
Paul Crowley (Paul@crowleyp.demon.co.uk)
Tue, 30 Jul 96 15:27:19 GMT
In article <4th488$lc0@portal.gmu.edu>
herwin@osf1.gmu.edu "HARRY R. ERWIN" writes:
> : > The niche is large-bodied suspensory feeding in open-canopy forest.
> : > [..] you have to climb down out of the tree to move to another tree.
>
> : Do you really believe this? Or are you just repeating a formula?
>
> Yes, I believe this. Published studies of Pan trog. and Pan paniscus show
> that Pan trog. never bridges and Pan paniscus rarely bridges.
I was querying: "The niche is . . . . ". It is not one currently
occupied by any animal. It is an imaginary niche -- and therefore
highly suspect.
> There have been semi-terrestrial hominoids for about 20 MYr, but our
> ancestors came down to the ground sometime between 10 and 4 MYr ago.
What real evidence is there for "our ancestors came down . 10 to 4 Mya" ?
> : > In relatively closed open-canopy forest, a bipedal stance doesn't
> : > give you useful early warning of attack.
>
> : Again: Do you really believe this? Or are you just repeating a
> : formula? Have the assumptions involved here ever been tested in
> : the real world?
>
> This comes from study of human populations and the reason why they put a
> lot of effort into cutting down underbrush in the areas they live
> in--visibility. Also studies of infantry attack on tanks and the factors
> that lead to success or failure. (I used to be an operations analyst
> specializing in this area.)
There is a vast difference between the reasons early hominids might
have for walking tall while trying to look over the high grass to see
lurking lions while also hoping the lions did not see them (I'm having
some difficulty visualising this) -- and the reasons why modern Hss
might cut down underbrush; let alone infantry tactics with tanks.
> : Nearly all the lethal
> : attacks on vulnerable chimps, baboons, or other primates appear to
> : occur when a single victim is feeding or resting in a tree and the
> : attacking group moves silently on the ground to cut off all avenues
> : of escape.
>
> Not very applicable to leopard attacks, then.
Leopards are mostly nocturnal. They're why chimps sleep in trees.
> They're a good deal more comfortable in an area with little undergrowth
> so they have good visibility.
Now you're talking! Animals that do stand tall for extra visibility,
such as meercats, do not live in forests; they inhabit open, fairly
flat areas with good lines of visibility. Places where you can see
significantly more with a bit of height. Even in such locations, I
still can't believe that another foot or so would be enough to justify
the adoption of a bipedal gait.
Paul.
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