The problem presented itself to me, in the first instance, curiously enough, as a kind of follow-up of my criticisms of Wynne Edwards. You remember that Wynne Edwards had been arguing that certain kinds of behaviour were the result of group selection, and I had been very critical about the possibility that group selection could produce the kinds of results that he was claiming. And then I sort of stopped to think and realised that the conventional view, even within evolutionary genetics - you can even find it in RA Fisher - of sex, was that its presence was because it was good for the population. And the standard work on the subject, I suppose, in those days, was a book called The Evolution of Genetic Systems by Darlington. It's a fascinating book, I mean, full of really good biology and interesting problems, but essentially group selectionist. Sex is to be explained because it is good for the species. And I remember sort of thinking, well, now, it really isn't fair that I should go around bashing Wynne Edwards for his group selection views on behaviour if I'm accepting a group selection explanation for sex. I mean, it really doesn't seem... seem right. And that's what made me start thinking about the problem. And the problem can be... in its stark form can be explained very simply, and it's this; imagine a species in which... and think not of ourselves, where there's parental care, but I tend to think of something like a codfish or something, which doesn't look after its kids - and imagine a gene and mutation causing females to... not to mate, not to go through the process of meiosis and production of a reduced egg, but simply to produce eggs, diploid eggs, genetically identical to themselves, and lay them, without bothering with males, and that those eggs, being genetically identical to the female, would also develop as females. In other words, what we call ameiotic parthenogenesis.