Negative capability

A commenter over at Sarah Hoyt's place mentioned that Freeman Dyson used to run simulations of systems that might result in a decrease in the world's human population, and that the only factor that consistently worked was the introduction of reliable electricity to fast-breeding cultures.  I spent some time this morning trying to track down more information about that interesting line of inquiry, but failed.  Instead, I came across this refreshing interview with Mr. Dyson on the subject of the origin of life, in which he time and again declines the interviewer's invitation to express a view on a controversy about which he is either not fully up to speed, or about which any answer must be the rankest sort of individual speculation.

Keats famously endorsed "negative capability," the willingness to endure ambiguity.  It may not always be such a terrific idea in moral matters, where it often seems to take the form of choosing not to be aware of what we already know perfectly well, such as that it's not possible to excuse systematic lechery with the phrase "I'm a hugga."  Nor have I ever been convinced by his idea that poetic aesthetics trumps all other considerations.  Nevertheless, the capacity to remain "content with half-knowledge" is a fine thing for a scientist.  Dyson candidly refuses to pretend that he knows what he doesn't.

I particularly enjoyed this exchange:

Suzan Mazur:  You draw an analogy in your book between origin of life and the origin of body plans half a billion years ago, a "sudden efflorescence of elaborate body plans," during the Cambrian explosion.  Have you had further thoughts about this in light of the "evo-devo revolution"?  Did form come first or did form arise from genetic programs? . . . 

Freeman Dyson:  By the time of the Cambrian explosion is very late in the history of life and genetics had become very powerful.  But, of course, we have no idea what happened in detail. 

Suzan Mazur:  How soon do you think we'll get to the bottom of things regarding origin of life, i.e., make the breakthrough? 

Freeman Dyson:  Give it a hundred years, perhaps, but I don't think my prediction is worth anything.  It all depends on what nature says, because nature is always surprising us. And probably in this case too. 

Suzan Mazur:  A hundred years.  You think it's going to take that long? 

Freeman Dyson:  Well I would call that short.

The origin of life is one of my favorite scientific mysteries.  Where I always get brought up short is the explanation for how replication started in the first place.  Once you have both a metabolism ("defined in a general way as the evolution of a population in which some of the molecules catalyze the synthesis of others") and a replicating system, it's easy enough to see how the ones with a successful metabolism will out-replicate the others and glom onto more metabolic resources.  But how do you get started on this pairing?  How do clumps of chemical reactions start to replicate and compete?  Dyson thinks that a profitable area of study would be how pre-biotic chemical reactions spontaneously form a rudimentary metabolism, which they clearly do in the lab; advances in nano-technology are opening the door for better experiments in this area.  Next, he thinks that some kind of primitive self-replicating mechanism formed (rather as crystals automatically replicate) and made its living for a while as a parasite on the metabolic system.  Eventually host and parasite merged and became the earliest precursors to cells, in the form of lipid walls enclosing little globs of water with a lot of stuff dissolved in it.  Later, the replicating mechanism developed into the advanced form of RNA, setting the stage for the "RNA world" that's captured so much attention in recent years.

If he turns out someday to be right, that would make us mongrels at least twice over:  once from the mating of metabolisms and replicators, and next from the capture of mitochondria by their host cells.