Chimps kill chimps. And according to a 10-year study of Ngogo chimps in Uganda, they do it to defend and extend their territory. John Mitani documented 21 chimp-on-chimp killings during the study, 18 of which his team witnessed. And when the chimps kill another, they take over its land. Because of the 1 percent difference of DNA between us and our ape cousins, it can be irresistible to anthropomorphize them, referring to their deadly attacks upon each other with terms like "murder" or "crime." And given the murders over territory that litter human history books, it's hard not to see echoes of our ourselves in chimp "warfare."
Chimpanzee warfare is of particular interest because of the possibility that both humans and chimps inherited an instinct for aggressive territoriality from their joint ancestor who lived some five million years ago. Only two previous cases of chimp warfare have been recorded, neither ...
