So, according to a BBC article, speciation happens from a mix of geographical separation and sexual selection.[1] Its really not a bad theory, at least to explain some of the speciation that has necessarily occurred for evolution to be true. It might even be sufficient to explain all or most of it. The sex drive is certainly one of the more powerful motivations. But the explanation as stated here is totally insufficient. They have not observed speciation yet, just something they think will lead to speciation. Alternatively, this could simply lead to a situation like that of the the wolphin's[2] where two groups rarely mate, but could, and so are not in fact distinct species, though they end up classified as such. Still, credit where credit is due: this does in fact represent research into one of the areas where existing Darwinistic theory has so far failed. As such is to be lauded as an example of true science over philosophy masquerading as science.
[1] Kettlewell, Julianna. "Butterfly unlocks
evolution secret" BBC (online) 2005-07-24.
http://news.bbc.co.uk/2/hi/science/nature/4708459.stm
[2]
Schierer, Luke. "20050415-1020" Random Unfinished Thoughts 2005-04-15.
http://www.schierer.org/luke/log/20050415-1020/20050415-1020