Sunday, December 06, 2009

Getting from A to B

Biologist and science writer Nick Lane has a new book out called Life Ascending: The Ten Great Inventions of Evolution. Any list of ten will inevitably be idiosyncratic, but here's Lane's choices:
1. The origin of life
2. DNA
3. Photosynthesis
4. The complex cell
5. Sex
6. Movement
7. Sight
8. Hot blood
9. Consciousness
10. Death
One might reasonably add proteins, fermentation, respiration, embryonic development, multicellularity, smell, and so on, but let's not quibble. Perhaps the most shocking item on any list of evolution's "great inventions" is death, but without death we wouldn't have the other things on the list.

We don't yet have a complete understanding of how any of these things evolved. Lot's of good ideas, yes, such as the origin of the eukaryotic cell by symbiosis of prokaryotes. But those who see the hand of an Intelligent Designer in these "inventions" have lots of wiggle room for speculation.

I have reviewed here Richard Dawkins' new book The Greatest Show On Earth: The Evidence for Evolution. Dawkins makes it all sound like an open and shut case, which it isn't. For all we know, some major new concept will be required to give the story completion. And if that's so, why do scientists so adamantly exclude a Designer as a missing factor?

For two reasons. First, it simply applies a word -- "God" -- to get from A to B, a word that has zero possibility of empirical study or verification. "Hocus-pocus" has exactly the same expanatory power. Second, and equally important, is Ockham's Razor: Don't invoke a supernatural explanation until natural explanations have been exhausted. For all of the "inventions" on Lane's list, we are a long way from exhausting natural explanations. In the meantime, we say, "I don't know, but here are some ideas worth pursuing."