We know that a lot of organisms, from humans to bacteria to birds to bees, have lots of sex. But what has mystified scientists for years is WHY. I mean, it’s fun and all (unless you’re a poor beetle girl stuck with this), but what purpose does it serve? On the face of it, in fact, sex seems to be pretty BAD for about half of the population: the women. For example, there’s a lizard out there than can reproduce both asexually and sexually. When it reproduces asexually, it producing nothing but girls, all of whom can reproduce both asexually and sexually. Net win. But when it reproduces sexually, it will produce about 50% BOYS, which can only reproduce sexually, and if they aren’t lucky and their courtship messages suck, they won’t even do that. Why bother?! Why not just keep reproducing asexually and passing your genes directly on (no mixing!) to hundreds of thousands of lizards?
For many years scientists puzzlesd over this one. But recently, a series of three new hypotheses has been formed. Welcome to the good, the bad, and the ugly.
Zimmer. “On the origin of sexual reproduction” Science, 2009