Stay or stray? Study delves into sexual behaviour

Scientists said Wednesday they had amassed the first evidence to back theories that people fall into two broad categories—promiscuity or faithfulness—when it comes to sex.

Competition among worm sperm speeds up evolution

From elaborate dances to stunning plumage displays to dramatic head-butting, male animals have an array of ways to distinguish themselves from competitors while wooing a potential mate. But it's not their only chance to prove ...

page 1 from 3