[lbo-talk] lbo-tech-talk

Chuck Grimes cgrimes at rawbw.com
Fri Oct 27 07:47:08 PDT 2006


``You might get a kick out of this if you don't already know it: (D'Arey Wentworth Thompson, On Growth and Form)...'' Andy F

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It's one of those books I came across a long time ago (I think in an art class) and kept intending to buy and never did. I seem to remember that Stephen J. Gould spend some time discussing Thompson at length, and partly dismissing some of it and partly incorporating it in a different way. But I can't remember the details. This was in The Structure of Evoltuionary Theory, which I just could't finish.

``..Gravity certainly has an effect on evolution and morphology, but simply as a body force -- you needn't appeal to any property specific to gravity at some fundamental, uh, trans-Newtonian level. You can call it a generic force and leave it at that...'' (AF)

Perhaps your're right, I am making it overly complicated. But gravity comes up again and again in different ways beyond its potential morphological effects. For example most of the higher animals use a gravity-sensor like arrangement in their semi-circular canals. These are usually arranged in what looks a lot like the Euler angles used in mathematical physics to locate points in space. The point here is that the directed force is sensed and is the primary direction-orientation against which animal perception and motion is coordinated.

In the higher plant you can show that they grow up and that directed growth is light-mediated, but light is not the primary entrainment source of the directed growth. What the plant cells are responding to are the gravity generated forces on the internal structure of the cells. A similar kind of internal force response is present in bone growth. The forces actually stimulate the bone cells to creat their mineral matrix.

More later. Gotta go to work...

CG



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