Tuesday, February 08, 2005

World without Darwin

A pretty unwieldy essay by Freeman Dyson appears in technology review . Dyson, who's not afraid to think big , manages to summarize 3 billion years of earth life, and pummel biologists besides, all in about 500 words.

So to take a tiny piece of this essay, he talks about prebiotic chemistry on earth, in which chemical reactions resembling the essentials of earth life (see here for an introduction to the idea of a "minimal cell") took place probably in the absence of one another. In this case, Darwinian selection, in the sense of survival and propagation of organisms, would not take place, and instead the cocktail would be a community sharing resources (and possibly genetic information). This, Dyson says, is life before Darwinism.

Yes, I would say, "life" without beaks of finches, but not necessarily "life" without natural selection. In fact, quite a lot of speculation on the origin of life centers on the idea that the right kind of chemical soup might self-organize, with more efficient reaction centers somehow shouldering aside their less efficient neighbors-- i.e. natural selection at the level of individual lipid micelles, or grains of clay, depending who you read. Not that this is thought out-- not by a long shot-- but I would consider Dyson's restrictive definition of Darwinism as tossing out your tool kit right when you need it most.

Dyson goes on to say that humans are making a evolutionary hash of the biosphere. I agree, but again, natural selection predicts how exactly this is happening. Anthropogenic processes are making ever-more-powerful parasites and ever-more-vulnerable crops. But this isn't post-Darwinism. If anything, it's Darwin on steroids.

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