Incest and folk-dancing: why sex survives

To launch the 2010/11 season of UCL's Lunch Hour Lectures, Professor of genetics Steve Jones will unravel the taboo subject of incest, arguing that it is much more common than most people think. In fact, you might have unintentionally committed it yourself. The lecture will explore why inbreeding is an escape from true sexual reproduction, how some creatures abandon sex altogether, and how mating within the family is still surprisingly common in some populations (including some within Britain) although it may, at last, be on the way out. Sir Thomas Beecham once said: "Try anything once but incest and folk-dancing" (he pointed out that brass bands, too, are all very well in their place, "in the open air and several miles away"). Sex with a relative is often frowned upon, but is in fact universal, for we all share ancestors in the recent past. ?Incest means having sex with a relative - and we all indulge in it, whether we realise or not. On average, two randomly chosen British people are sixth cousins, which means that they share an ancestor who lived in the year of publication of The Origin of Species (1859),? explained Professor Jones. Darwin - who himself married his cousin - was concerned about the possible health effects of inbreeding. He found, for example, that the offspring of cousins were less likely to find a place in Oxford and Cambridge boat-race crews. Darwin also developed an ingenious way of measuring its extent: how often do two people with the same surname marry?