Over the last thirty years, many scientists have come to insist that our behaviour is governed by our genes-above all when it comes to sex, which, we are told, is how genes perpetuate themselves. Sex certainly seems more complicated than a matter of our DNA struggling to survive and that's because it is. Eldredge directly confronts those who would cast us as puppets of biological imperatives rooted deep in our hunter-gatherer past. Their models, he points out, are based on lower forms of life. In humans, there is an intricate interplay between meeting our needs for day-to-day survival, sex and reproduction (the human triangle)-further complicated by cultural forces (customs, laws) that routinely override selfish-gene behaviour. rethink the assumptions of today's science in the important task of understanding ourselves.