Genetic correlates of social behaviour in wild chimpanzees: evidence from mitochondrial DNA

This study explored some aspects of chimpanzee social behaviour using mitochondrial DNA sequence data as an index of matrilineal relatedness. The hypothesis tested was that matrilineal relatedness predicts social affiliative preference in wild chimpanzees. Several behavioural measures of individual social preference were examined for chimpanzees from Kanyawara community in Uganda's Kibale Forest. None of the four pairs of strongly affiliative males in this community could have been maternal brothers, since no pair shared the same mitochondrial DNA sequence. Fourteen chimpanzee communities outside Kibale, for which no direct behavioural data were available, were also studied by using communal nesting as a rough index of affiliative preference. Again, chimpanzees that nested together did not tend to be matrilineally related. The results suggest that kin selection is weaker than previously thought as a force promoting intra-community affiliation in chimpanzees. (C) 1997 The Association for the Study of Animal Behaviour.