Proceedings of the National Academy of Sciences: After the Ngogo chimpanzee group killed 21 members of neighboring groups and expanded their territory by 22%, female birth rates more than doubled and infant survival increased sharply—showing clear fitness benefits from intergroup killing. In PNAS: https://ow.ly/TKmf50XuPjY

After the Ngogo chimpanzee group killed 21 members of neighboring groups and expanded their territory by 22%, female birth rates more than doubled and infant survival increased sharply—showing clear fitness benefits from intergroup killing. In PNAS: ow.ly/TKmf50XuPjY