Quoted: "That's the best theory going right now... You have to keep running on the treadmill of evolution or you fall off. The germs are mutating like a son of a gun, but with sex you can derive these crazy new gene combos that lock them out. Beat that!"

- Bill Nye the Science Guy, when asked by Wired about the "Evolution of Sex" episode of his new TV show. In it he says "The main function of sex is to keep germs and parasites at bay."