Re: Limbs and niche partitioning

[Stanley Friesen <sarima@ix.netcom.com>]

At 05:37 PM 10/1/99 +1000, Adam Crowl wrote:
>Hi Dino List,
>
>Hmmm... is this some how connected to the origin of bipedalism in dinosaurs?
>If so consider the aquatic ape theory of Elaine Morgan which seeks to
>explain human bipedalism by postulating that a group of LCAs between humans
>and chimps was isolated on an island roughly in the Afar Triangle c. 6-4
>mya. They adapted to a partially aquatic life style and when the Afar dried
>up the now bipedal apes rejoined their African cousins.

Unfortunately, the Aquatic Ape Theory is pretty much hogwash.  To be blunt,
Ms. Morgan is a crackpot.

For one thing it ignores the pre-adaptation to bipedalism in extant apes.
>
>Why did they become bipedal? Well it's only in water that the African apes
>will habitually walk upright - bonobos do so in flooded forests,

And about any other time they walk on the ground.  Unlike the common chimp,
bonobos use bipedal walking quite frequently.

> gorillas do
>so to cross streams,

But knuckle-walking, which is what they do the rest of the time, is really
semi-bipedal anyhow.

>Sure gibbons and orangs are semi-bipedal on tree branches, but when on the
>ground they don't bipedal for long.

Actually, gibbons on the ground (which is rare) are *obligate* bipeds.
What they don't do is stay on the ground very long.

--------------
May the peace of God be with you.         sarima@ix.netcom.com