| Chapter 2: | Humans |
leaped to the conclusion that humans are naturally barbarous, just like their close relative the chimpanzees (Goodall, 1986) (see chapter 3).
However, chimpanzees and human beings are very different in ways that count: in behavior and especially in relationships between males and females (Diamond, 1997). Research in anthropology, physiology, and anatomy as well as other evidence shows that since diverging from a common ancestor about 5.4 million years ago (see figure 1), human forebears and chimpanzees evolved completely different mating systems. Not only that, but chimpanzees and bonobos, which are more similar genetically than humans and chimpanzees, also evolved different behaviors. The mating system of bonobos is no more like that of chimpanzees than humans’ is, and bonobos are in many ways more similar to humans than they are to their nearest kin, chimpanzees. Jared Diamond argued on multiple lines of evidence that the common gorilla-chimp-human ancestor lived in harems (one male in a stable mating relationship with several females). Gorillas maintained this model and chimps and bonobos invented promiscuity (though with very different expressions of it), but humans lived in nuclear families. Nuclear families and their origins are explored in chapter 6.