EVOLUTION: The Aquatic Ape

John K Clark (johnkc@well.com)
Sat, 18 Jan 1997 08:06:00 -0800 (PST)


Mark Crosby <CrosbyM@po1.cpi.bls.gov> On Fri, 17 Jan 1997 Wrote:

>the need to cover greater distances meant we would have
>needed an alternate way to run fast, e.g., bipedalism;

There is nothing fast about bipedalism. Humans have good endurance, because
they have no hair and are good at getting rid of waste heat, but as for speed,
with the possible exception of the ground sloth humans are the slowest mammal
on earth.

>being able to stand fully erect also allows the animal to
>see farther across the open savanna and more ably find prey
>or avoid danger

Lots of animals can stand on their hind legs, you don't need to develop
bipedalism for that.

Michael Lorrey <retroman@tpk.net> Wrote:

>the analytical abilities of hunting were amplified in males

Scavenging was probably much more important than hunting at this stage.

>On flat plains with high grass, the higher you can stand,
>the earlier you get a warning of predators.

If you can see a predator better by standing up high, it also means that the
predator can see you better too, and because you're bipedal, the predator is
a lot faster than you are. If you can't run away from danger a better
strategy would be to hide and keep low.

>Additionally, the ability to throw rocks and spears with
>decent power over decent distance also mandates an upright,
>high stance with a hip structure that also is conducive to
>bipedalism over quadupedalism. This is a fine example of
>technology effecting evolution.

But there were no spears, or tools of any sort at that time, ancestors like
Lucy (Australopithecus Afarensis) with their tiny, chimp sized brains were
too dumb to make them. The first very primitive tools were made by
Homo Erectus, an animal with a much larger brain than Lucy, although much
smaller than modern brains. These very early tools do not show up in the
fossil record until well over a million years after bipedalism was fully

>Due to the computational demands of intuitive trajectory
>calculation, and the communication demands of hunting in
>teams or packs, lager brain cases were seen as an
>evolutionary advantage.

It's hard to believe that a pea brain like Lucy could do something that
sophisticated, throwing something accurately is very difficult, it takes a
lot of brain power. Even modern humans would have a hard time making a living
by throwing baseballs at swiftly moving animals, much less irregular shaped
shaped rocks.

John K Clark johnkc@well.com

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