Evolution of Laterality

Peter Passaro (ocsrazor@worldnet.att.net)
Sun, 22 Nov 1998 22:16:46 -0500

Thanks to Tim for the cite on the Throwing Madonna hypothesis.

Tim also wrote:

>Just going from memory re the content of this paper, but this is, I
>believe, the source. Of course it may data back even further?

Maybe, "The Throwing Madonna" was first published in 1983

> I don't believe it. There seems to be a consensus, however, that the
> origins of which side got chosen to be the left/language/generative
> grammar side are probably incidental to _some_ artifact of this nature.

I don't know if I buy it either, but of the available prospects, it is the
only one with any viable leads. There must have been some strong selection
pressure towards right handedness at some point in our not too distant ancestors. But answering this question is almost as bad as asking why all biological molecules are dextro-chiral (too much lost data in the intervening time span and it may have been a haphazard accident anyway).

>Doesn't really matter too much, I suspect.

It matters to me in the sense that I have a deep need to understand why all the parts work as they do and how they got there in the first place from a biological engineering standpoint (especially where the mind is concerned). The adaptability of an organism is by far its strongest trait in determining its survial. Any clues that past adaptation may provide are guideposts for the engineers of Homo sapiens sapiens 2.0 etc.

>The big thing is that the world is constructed as generative objects on
> the left and as synthetic spatial maps on the right.

This statment and your subject title reminds me of another question I've being
meaning to ask of a biological mathematician. Any professors to this title
on this list? (pun intended). As organisms (or any system for that matter) become more complex they show an increasing degree of body plan lateralization. Is this simply because there is more opportunity for loss of symmetry and division of labor? I suspect compexity theory would have something to say about the reasons and the likelihood for a biological system to develop in a nonsymetrical pattern. Has Stewart Kauffman said anything on this matter? Any comments? Peter