So wrote Charles Darwin in 1862. In this week’s issue of Science, I write an essay on what we know now about this mystery. The essay is here (subscription required), and you can listen to me talking about why sex is weirder than you know on this week’s Science Podcast.
To continue this celebration of sex in all its evolutionary glory, I’ll be guest-blogging a few times this month over at Science‘s Origins blog. I’ll let you know here when each post goes up.