A question of sex

August 21, 2009

Caster Semenya’s victory in the 800-metre final at the World Athletics Championships in Berlin has been overshadowed by the controversy surrounding her sex. After the race on 19 August, the International Association of Athletics Federations announced that they had asked Semenya to undergo tests to verify that she was female, with IAAF spokesman Nick Davies describing the tests as “extremely complex, difficult”. Here, Nature looks at the science behind the latest gender row to hit sport. (Nature News)