Saturday, October 11, 2008

What is life?

I have been a cheerleader for Stuart Kauffman since I read Origins of Order: Self-Organization and Selection in Evolution back in the early 90s. Something is going on in biological systems that reductionist science cannot account for, said Kauffman. In 1996, I wrote:
Kauffman thinks laws of self-organization lie at the heart of nature. If we can discover these laws, he says, we will understand how our bodies developed from a single fertilized egg, and how our species emerged over billions of years from prebiotic chemicals. He is a long way from finding the laws he is looking for, but the results achieved so far hint at a directionality and inevitability to evolution that may not be fully accounted for by Darwinian natural selection.
In Investigations (2000), Kauffman wrote: "[T]he biosphere, it seems, in its persistent evolution, is doing something literally incalculable, nonalgorithmic, and outside our capacity to predict, not due to quantum uncertainty alone, nor deterministic chaos alone, but for a different, equally, or more profound reason: Emergence and persistent creativity in the physical universe is real." We know a lot about life, he says -- molecular machinery, metabolic pathways, means of membrane biosynthesis, and so on -- but what makes a cell alive remains deeply mysterious. Kauffman wants to find laws that account for self-organization of novelty.

Well, yes. It is easy to agree with Kauffman that there may be more afoot in the world than we currently understand. But so far, Kauffman and other champions of "laws of emergence" have not come up with anything particularly useful. Sometimes Kauffman's speculations sound like a kind of pervasive, built-in "intelligent design" -- a stealth supernaturalism, or at best a resurgent vitalism. He talks a lot about "autonomous agents," then looks for laws to account for their autonomy, which seems a curiously oxymoronic program. Fifteen years after Origins of Order, natural selection remains far and away the most productive way of accounting for biological diversity. I'm still rooting for Kauffman, but so far, emergence is just a code word to cover our ignorance.