The Red Queen: Sex and the Evolution of Human Nature

by Matt Ridley

If we were pygmy chimps or bonobos, we would live in groups much like those of chimps, but there would be roving bands of dominant men who visited several groups of women. As a consequence, women would have to share the possibility of paternity still more widely, and female bonobos are positively nymphomaniac in their habits. They have sex at the slightest suggestion and in a great variety of ways (including oral and homosexual) and are sexually attractive to males for long periods. A young female bonobo who arrives at a tree where others of the species are feeding will first mate with each of the males in turn—including the adolescents—and only then get on with eating. Mating is not wholly indiscriminate, but it is very catholic. Whereas a female gorilla will mate about ten times for every baby that is born, a female chimp will mate five hundred to a thousand times and a bonobo up to three thousand times. A female bonobo is rarely harassed by a nearby male for mating with a more junior male, and mating is so frequent that it rarely leads to conception. Indeed, the whole anatomy of male aggression is reduced in bonobos: Males are no larger than females and spend less energy trying to rise in the male hierarchy than ordinary chimps.