Joan Roughgarden, a biologist at Stanford University, believes that Darwin’s theory of sexual selection is fundamentally flawed. The data that calls it in to question is the otherwise unacknowledged and unexplained prevalence of homosexual behavior in the animal kingdom. Based strictly on the summary of her theories provided in the linked article, I find myself agreeing with the critic who said, “You don’t have to dismiss the modern version of sexual selection in order to explain social bonding or homosexuality,” but her theories are definitely interesting. (Thanks Roy)