Re: Could a. ramidus prove AAT?

Phil Nicholls (
4 Jan 1995 21:19:43 GMT

In article <>,
Troy Kelley <> wrote:
>I wish I had more time to give to this post, but I just wanted to throw
>out this idea.
>BTW, happy new year to everyone out there. I have really enjoyed this
>group, even though it can be confrontational at times, most folks seem to
>keep to the issues and don't resort to name calling.

Troy, you ignorant slut. ;-)

>I did track down the "Nature" article on a. ramidus, and while I did not
>understand most of the "dental" sections (I need to brush up on my dental
>anatomy knowledge) I did see that they didn't have enough evidence to
>determine whether the a. ramidus was bipedal or not.

The position of the foramen magnum is consistant with a biped and this
is essentially the same kind of evidence Raymond Dart used originally.

>But, suppose they do discover more a. ramidus remains and it is concluded
>that it was bipedal and lived in the forest and not on the savanna, that
>would put some holes in the "savanna promotes bipedalism" arguments. So,
>if that is the case, what would be the arguments for bipedalism for a
>forest dweller?

Bipedalism doesn't have to originate on the savanna but it certainly
provides several advantages once your there. A forest origin makes
some sense in terms of the biomechanical aspects of hominid bipedalism.

>There was a previous post by someone (Phil, was that you?) who said
>chimpanzees had been observed running along next to river beds in a
>bipedal manner. Also that they were wading into water to catch fish.
>Perhaps this is what encouraged a. ramidus to do the same?

The evidence is anecdotal but what has been observed is that bonobos
(pygmie chimpanzees) walk bipedally more than any other ape, have an
upperlimb/lower limb ratio VERY similar to Lucy. When walking along
river banks or in shallow stream water they will walk bipedally. It
is suggested they may be catch small fish.

The problem with applying this to protohominids is that there is no
way to test it. It would also not explain a loss of body hair or
any of the other "aquatic" traits Morgan lists.

>I can think of a few things that would encourage bipedalism of a
>tree-dweller (running between trees) but most of these would favor
>quadrapedalism more because that is more efficient. Most tree-dwelling
>monkeys run on all fours when they hit the ground because it is simply
>faster than two legs. So, what could possibly encourage bipedalism from
>an early tree-dwelling primate? I think wadding in shallow streams and
>rivers (which many times run directly through dense African forests) is a
>very plausible answer.

What a monkey does when it is on the ground depends on what it does in
the trees. Arboreal quadrupeds are quadrupeds on the ground. Spider
monkeys, which are vertical climbers and suspensory feeders, will walk
bipedally when on the ground.

Philip "Chris" Nicholls Department of Anthropology
Institute for Hydrohominoid Studies SUNY Albany
University of Ediacara
"Semper Alouatta"