Wednesday, November 02, 2005

Darwinian Niches

Darwinian Micheal Ruse has posted a longish but interesting essay to the Philosophy of Biology blog. He's responding to another writer, Conway Morris, who has suggested that life evolves to fill various niches - water, land, air, etc. Conway cites as proof the fact that we can find examples of where unrelated life forms took very similar paths and wound up with very similar designs, which suggests that there are pressures on evolution that favour some paths more than others. The probabilities are not equal. Ruse then goes on to get very philosophical and very interesting by asking if there is a reason to think that all of the available niches are visible to us. Ruse's answer is: No. So, if there are more niches than we know of, and there is pressure on life forms to fill those niches, perhaps they are already occupied?
If we do have a progression of niches - water, land, air, culture - why stop with culture and intelligence? Why not move on to another basic niche - why not move on to an infinity of such niches? You might say that you cannot imagine what a further niche would be like. This is no argument to a Darwinian. Natural selection has made us able to deal with our experienced circumstances - getting out of the jungle and on to the plains, for a start. There was neither need nor obligation to give us the powers to peer into the ultimate mysteries of creation. Being too philosophical can have its downside. It makes for worry and doubt and indecision. Is there reason to think that there is more than we can comprehend fully? Today's science answers affirmatively. Think of quantum mechanics. "Modern physics teaches us that there is more to truth than meets the eye; or than meets the all too limited human mind, evolved as it was to cope with medium-sized objects moving at medium speeds through medium distances in Africa" (p. 19). Should we think of the next niche up as the world of super intelligence, perhaps the sort of dimension reported on by mystics? Well, you can if you want, but speaking as a Darwinian this is not terribly helpful or insightful. The whole point is that it is a dimension of which we are ignorant. It is not be so much a world where the laws of nature as we know them - logic and mathematics, too - are broken. It is certainly not be a world to bring comfort to anti-scientists like the Creationists. It is simply be a world beyond our ken.
Much to his credit, Ruse allows what philosophers of science have been saying for a long time. Positivism, which over zealous use of Occam's Razor leads to, is a chosen method, not a neutral one, and it brings unproven assumptions with it. Using such a methodology to "prove" the non existence of God or that metaphysics has no value is a joke. Why is it a joke? Because it's utterly circular; the conclusion is contained in the method and not in the proof offered. What Ruse is suggesting in this essay is that Darwinism neither proves or repudiates religion, but does raise questions that it cannot answer and that ought to tell us something about the limits of its method and claims made in its name.

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