Re: Bipedalism and theorizing... was Re: Morgan and creationists

Paul Crowley (
Sun, 04 Aug 96 16:08:41 GMT

In article <4tibn9$> "HARRY R. ERWIN" writes:

> 2. The issue of motor programs is a lot more important than
> non-specialists are aware. [..]
> obstacles, using somatosensory and tactile afference. When a gibbon is
> swinging along at speed, almost all of the computation is going on in the
> spinal cord with practically no input from the head. If you've ever seen a
> decorticated cat preparation walk, you know what I mean.

I haven't seen this. Is it the same sort of thing as the walking
of a headless chicken?

Do you mean that a decorticated gibbon would brachiate?
Would the bipedal motor automatic response have reached our spinal
cord? I have never heard of a soldier whose brain has been shot
away continuing to walk forward. If it were to happen it would have
done so thousands of times in, say, WW1.

My own (utterly ill-informed) suspicion is that bipedalism has not
had enough time to get integrated into our spinal cord, and that
much the same would apply to the brachiation of a gibbon.

> The implication is that a major change in locomotor adaptation involves
> changing those motor programs.