Seven Clues to the Origin of Life, by A. G. Cairns-Smith
Amusing and readable book about what the first replicators weren't, and might have been, like
(Review posted 2 Mar 2006 00:22:17)

I found this book while doing some research in the aftermath of an online discussion of just how unlikely the formation of the first replicators (the first things that could undergo evolution) was.

In that discussion someone had remarked (after reading some creationist stuff) that it was just fantastically impossible for the first cell, or even the first nucleotide, to come together more or less by accident. I replied that of course no one serious thinks that the first replicator was a whole cell, or even a modern sort of nucleotide; it was presumably some very low-tech and inefficient thing, just barely able to reproduce itself imperfectly once in a blue moon. After I said that I realized that while it seemed perfectly obvious to me, and that all right-thinking people must agree, I didn't specifically recall any of the right-thinking people in question. So I went and did some research, and (among other things) I found this book.

In "Seven Clues to the Origin of Life", A. G. Cairns-Smith, a molecular biologist and so on at the University of Glasgow, lays out in an amusing and chatty way (including numerous Sherlock Holmes quotations) his argument that yes the first replicator really couldn't have been any of the replicators that we have today, or even anything very much like them. And he presents his own theory as to what they in fact were: inorganic clay crystals of a certain type that seem to have (or seem capable of having) both the requisite ability to do a kind of very low-tech replication, and the potential to have eventually provided the platform on which our current much higher-tech replicators (DNA and all that) got their start.

The writing is extremely clear and readable, aimed at a general non-technical audience, and the book is both fun and short (131 pages including glossary, index, etc). I'm not convinced by his argument that these particular clay crystals were the first replicators, but I'm very convinced that something at least vaguely like them could have been, and that therefore there's no really puzzling problem about how replication got started in the first place. Which is nice, because it's pretty clear that it did. *8)

Highly recommended to one and all. And if you really like the subject, there's apparently a longer and weightier and more technical book, "Genetic Takeover", in which he treats the same subject in more detail (and perhaps without the Sherlock Homes).