Discrimination of Paternal Kin in Wild Chimpanzees

University Of Minnesota-Twin Cities, Minneapolis MN

Investigators

Abstract

This project investigates whether wild chimpanzees (Pan troglodytes) recognize and treat paternal relatives differently from other individuals. Kinship can have a profound effect on the social behavior of animals and humans. By helping and refraining from harming their kin, individuals will benefit through the process of kin selection by increasing their genetic representation in future generations. However, to achieve these benefits, individuals must be able to discriminate kin from non-kin. In group-living mammals such as primates, individuals have been shown to discriminate maternal kin from non-kin, grooming them, aiding them in aggressive contests, and avoiding mating with them, thus avoiding the deleterious consequences of inbreeding. Although individuals will also benefit by discriminating paternal kin, this ability could not be explored in wild populations until the recent advent of non-invasive genetic testing that can now identify paternal relatives. This study will investigate three questions about paternal kin discrimination in the chimpanzees of Gombe National Park, Tanzania: (1) Do fathers discriminate and favor their genetic infants? (2) Do adolescent males that have left their mothers to join the adult male group preferentially associate with and receive protection from their fathers? (3) Do females discriminate and avoid mating with their fathers and paternal siblings as well as their maternal relatives? Genetic relationships will be established by analysis of genetic markers detected in DNA collected from fecal samples. Data on behavioral interactions will be extracted from the 44 year archive of field notes collected during Dr. Jane Goodall's study of the Gombe chimpanzees and stored in the Jane Goodall Institute's Center for Primate Studies at the University of Minnesota, as well as new field data collected during the project. Demonstration of paternal kin discrimination in chimpanzees will provide support for the general importance of kinship in social behavior, a matter of current debate. The study will fill an important gap in our understanding of the factors influencing the behavior of our closest living relative. Evidence of paternal kin discrimination in chimpanzees that live in patrilineally based societies will complement recent evidence from matrilineally based societies, extending the generality of the phenomenon. The study will also stimulate future research on the mechanisms involved in kin discrimination. In terms of its broader impact, the project will contribute to the education of both university students and the general public. It will employ both graduate and undergraduate students, actively recruited from underrepresented groups, and introduce them to the excitement of research on a species relevant to understanding human evolution. An interactive page on the Center for Primate Studies website www.discoverchimpanzees.org will allow the general public to read updates about ongoing field research and pose questions to the researchers. Web activities will be developed to explain kin selection, and paternity determination, and games will illustrate kin recognition, and inclusive fitness. Educational programs showcasing the project's research will also be developed with Lincoln Park Zoo (Chicago) and made available to Minnesota zoos. Research activities in Tanzania will employ and educate local people, and contribute to the conservation of an important endangered species.