Trouble is, experiments on bacteria suggest transposons may not be so damaging after all. By creating beneficial mutations as well as harmful ones, they might even help some organisms. The overarching question is whether sex is primarily about making sure that good genes spread or that bad ones don't. And here, says Hurst, 'we're squirming our way towards a final conclusion'. Some of us have more need to squirm than others.
Human biology is, it's true, wired up for sex and nothing else.
That means ditching males isn't yet an option for our own species. In the long term, though, it may be precisely what evolution is inexorably working towards. The irony is that the Y chromosome itself can reap none of the benefits of sex. All other chromosonies are inherited in pairs, enabling them to exchange genetic material with a partner. But not, alas, the Y chromosome.