In the Guardian, Paul Davies writes about investigating the origins of life on earth and, possibly, throughout the Universe. Davies, a media-savvy astrophysicist with a notable spiritual, if not mystical, streak, comes dangerously close to advocating something like Intelligent Design, albeit a more primordial level than its usual crackpot promoters. He talks about the existence of a “life principle”, egging those pesky little molecules in that primordial soup into somehow life-like combinations:
Because even the simplest living cell is immensely complex, the odds of such a thing forming by chance are virtually zero. If that’s the way it happened, then life is a freak phenomenon, and we will almost certainly be alone in the universe. However, the search for life beyond Earth, which underpins the burgeoning field of astrobiology, is based on a belief that chance played only a subordinate role. Instead, some sort of “life principle” is envisaged to be at work in the universe, coaxing matter along the road to life against the raw odds.
The problem here is “virtually zero”, which is not zero, combined with the usual fallacy of design-promoters: just because we aren’t smart enough, or just don’t know enough yet, to see the gradual steps between a random primordial soup and the first self-contained bacteria, doesn’t mean that it didn’t happen in gradual steps. The chances of life arising may be very small indeed at some particular time, in some particular bit of primordial soup, but over a billion years and immense numbers of combinations of molecules, lightning bolts and dirty water, all under conditions we don’t understand nearly well enough to enumerate in any precise way, makes it just as possible — given our meagre knowledge — that life in the Universe is unlikely as it is likely.
As a scientist with some desire not to descend completely into the depths, Davies claims some sort of testability for this “principle”, looking for mirror versions of the molecules like DNA, RNA and the like which are the basis of “life as we know it,” but which could have formed the basis for a parallel evolutionary tree if life were easy to form in the Universe. Interesting though those experiments may be (and, not being a xenobiologist, I’m not sure I can judge) they seem to be able to shed light not on any grand cosmic principles, but on the dirty and contingent — and wonderful as far as we should be concerned — mechanisms by which life formed here, in this one place, four or so billion years ago.
(Full disclosure, or possibly just self-aggrandizement: Davies has been a visitor here at Imperial, and I’ve written papers with Charles Lineweaver, one of his co-authors on this work.)
Also, I note with some sadness that today marks the passing of The Guardian‘s weekly science section, called “Life”, to be replaced in their coming re-design by a daily science page. Despite the brave face they try to put on it, this will almost inevitably lead to a reduction in science coverage.