The longer your generation time, the more genetic mixing you need to combat your parasites. - Matt Ridley

The genome is littered, one might almost say clogged, with the equivalent of computer viruses, selfish, parasitic stretches of letters which exist for the pure and simple reason that they are good at getting themselves duplicated. We are full of digital chain letters and warnings about marmalade.

The stuff of anthropology—the traditions, the myths, the crafts, the language, the rituals—is to me but the froth on the surface. Beneath lie giant themes of humanity that are the same everywhere and that are characteristically male and female. To a Martian an anthropologist studying the differences between races would seem like a farmer studying the differences between each of the wheat plants in his field. The Martian is much more interested in the typical wheat plant. It is the human universals, not the differences, that are truly intriguing.

Everything can be inherited except sterility. None of your direct ancestors died childless. Consequently, if we are to understand how human nature evolved, the very core of our inquiry must be reproduction, for reproductive success is the examination that all human genes must pass if they are not to be squeezed out by natural selection. Hence I am going to argue that there are very few features of the human psyche and nature that can be understand without reference to reproduction. I begin with sexuality itself.