I still do not understand fully why it took so long. I mean, Darwin put forward the idea in his book in 1871, and I think it's fair to say that - I understand why it was rejected at the time, and it very largely was, people did not take sexual selection seriously, essentially, I believe, it wasn't that they didn't like sex or they didn't like the notion of choice. I mean, choice was unmechanistic, they were trying to reduce behaviour to a mechanism, and they couldn't fit choice into a machinery. But it is very odd that it was a hundred years from Darwin's publication before people did serious work on the subject. I've talked to Peter O'Donald about this. Peter, who was a student of RA Fisher's, did mathematical models of sexual selection, which were really the beginning of all theoretical modelling of sexual selection, I think, they were good models. You know, what led him to do it. Because, I think, in some ways, those models were the sort of beginning of something. But there's an interesting piece of history there that I don't fully understand, as to why the enormous delay. And then, nowadays, you can't open a journal of behaviour without reading about sexual selection. But it's all happened in the last twenty years.