The first time marine biologist William Haddad and his team saw a seal rape a penguin, they were shocked.By the fourth time, they were convinced this bizarre behavior was becoming a trend.For 50 years, researchers from the marine mammal program at the University of Pretoria in South Africa have been taking weekly censuses of the elephant seal population on sub-Antarctic Marion Island, more than a thousand miles south of Cape Town in the Indian Ocean. In 2006, they saw something they'd never seen before. A fur seal (not the species they were studying) mounted and appeared to mate with a...