Evolutionary biologists have long argued that kinship was central to early human social groups, whereby relationships with relatives guided social interactions. Comparative studies of nonhuman primates have elucidated the adaptive significance of kinship. Such research has focused predominantly on maternal relatives, partly because many monkey groups are organized around matrilines of philopatric females, and partly because maternal relatedness is readily assigned through long-term observations of births. Certainly, however, individuals may be related through males too, but this phenomenon and its implications have been neglected due to the demands of determining paternal relatedness via direct genetic analysis. Recently developed noninvasive DNA sampling and population genotyping techniques now allow testing of hypotheses about the importance of paternal kinship. Through synthesizing behavioral and genetic data, this research addresses questions such as: 1) How do social interactions vary among paternal kin, compared to maternal relatives in a matrilocal society? (2) What benefits are gained through associating with paternal kin? and 3) What mechanism allows individuals to identify paternal kin? An 18-month field study conducted on two groups of olive baboons (Papio hamadryas anubis) in Kenya will address these questions. Behavioral data are gathered via focal animal sampling, and genetic relatedness is determined via non-invasive fecal sampling.
In addition to advancing our understanding of paternal kinship, this research contributes to broader educational and scientific initiatives in two ways. First, while abroad, the investigator is collaborating with the local elementary school to develop a series of lessons to help educate local Kenyan youth about local ecology and wildlife from a scientist's perspective. Second, she works closely with the Laikipia Wildlife Forum (an organization which prioritizes conservation endeavors in the proposed study area), providing information on local wildlife and ecology, as well as maintaining positive relations with the local communities.
An old proverb holds that "blood is thicker than water", which captures the notion that relationships among familial relatives have special significance in the societies of humans and in the behavior of individual people. Many cultural aspects of such partiality towards kin are well understood, but ever since Charles Darwin many people have wondered whether there are also biological bases of such social tendencies? Such a question is part of a larger scientific enterprise to understand whether patterns of social behavior of all kinds can represent naturally selected adaptations, just like the more commonly appreciated physical features of an organism, such as the structure of its teeth or the color of its fur. Research over the last 50 years has greatly clarified the adaptive nature of sociality in animals. A cornerstone of modern thinking on social evolution is William D. Hamilton’s theory of "kin selection," which is based on the concept that natural selection can promote cooperation and even self-sacrifice detrimental to one’s own survival if the individuals interacting with one another are genetic relatives. This insight has been called by one prominent biologist "the only true advance since Darwin in our understanding of natural selection." Although Hamilton’s model continues to be tested, research on animal behavior provided widespread support for his idea. Primate research is no exception, but primates have also generated a special problem. The majority of thinking and work on kin selection in primates has focused on matrilineal kin, i.e., females related through the mother. There are good reasons for this emphasis on "maternal kin." One practical motivation is that it is easy for researchers studying wild primates to know with some certainty who an infant’s mother is (due to nursing), and thus to build up, over time, knowledge of maternal lineages, but it is impossible to identify fathers reliably with observations alone. A second reason for this emphasis derives from the fact that the societies of most monkeys in Africa and Asia are "female-bonded", i.e., based on conspicuous social relationships among resident female relatives. Existing data demonstrate the importance of mothers, grandmothers, sisters, and maternal half?sisters in promoting the survival and reproduction of youngsters in these societies. As powerful and compelling as these studies are, however, they overlook a simple truth: everyone has a father too. Recent technological advances in the extraction and preservation of DNA from feces now allow us to tackle this problem and answer the question: to what degree do relationships with the father and with kin related through the father contribute to the well?being of youngsters in societies whose core is otherwise maternal relatives? We studied the social ramifications of paternal kinship in wild olive baboons (Papio anubis) that have been studied in Kenya for over a decade. Baboons live in classic "female-bonded" groups, which include many adult males. We studied immature baboons between the ages of 2-7 years for 18 months. We measured quantitatively their social bonds with one another and with resident adult males, how those relationships influenced the feeding behavior of the juveniles, and how juveniles interacted with others in the group, especially rivals, both adult and immature. We collected 138 fecal samples from which extracted DNA is currently being analyzed in laboratories at New York University and the University of Texas (Austin) to identify not only fathers, but how juveniles are related to others in the group: through the father, through the mother, or not at all. Because genetic and behavioral analyses are still underway, the results are not yet available, but they will eventually address questions such as: compared to the well?known contributions of maternal relatives, how do paternal kin assist growing juveniles, particularly when it comes to safety from social conflict with competitors and efficiency in foraging in an ecologically challenging environment? If positive effects of paternal kin for juveniles are confirmed by our analyses, such results will demonstrate that paternal relatives contribute significantly to the welfare of youngsters even though the social relationships between them are not nearly as prominent as those between youngsters and their maternal kin. Whatever the outcome, the results will significantly broaden our understanding of the action of kin selection. If kin selection theory represents the single most important advance in thinking since Darwin, then the study of patrilineal kinship in matrilineal societies arguably offers one of the most important advances since Hamilton in our understanding of kin selection. Execution of this research also allowed us to pursue several lines of broader impacts, such as completion of a PhD, outreach to programs in natural resource and wildlife education at local Kenyan primary schools, wildlife education to members of local pastoralist communities, pedagogical contributions to a Rutgers University field school in primatology and conservation for American undergraduates, and training of American undergraduates in genetic techniques in USA-based laboratories.
