The evolution and maintenance of group identity in animal societies

The evolution of cooperation is central to current understanding of how complex life forms and animal societies - including human societies - evolved. A key step in the evolution of cooperative societies is the emergence of phenotypic markers of group identity, which permit group members to discriminate fellow cooperators from outsiders. The formation of a clear group identity is regarded as a ‘core design principle’ in evolutionary and economic models of human cooperation. In biology it is the basis of social immunity and a key feature of major evolutionary transitions to new levels of organismal complexity. Yet very little is known about how or why individuals merge or suppress their individuality to form a coherent group phenotype, or the consequences of such behaviour for the phenotypic diversity of groups and populations. Wild animal populations, living in the environment in which they evolved and subject to natural ecological and genetic variation, are ideal systems to address these very general questions. This project addresses these questions by developing a new evolutionary theory of group identity formation and testing this theory using a model wild mammal system, the banded mongoose Mungos mungo. In this species, group members mix their individual scents to form a group-specific scent profile, which acts as a marker of group identity during highly aggressive intergroup interactions. We investigate the physiological mechanisms generating and constraining scent individuality, the predicted effects of intergroup conflict on identity signalling behaviour, and the causes of individual variation in group identity formation. The specific objectives are: 1. To develop a new theoretical approach to the evolution and maintenance of group identity. 2. To establish the proximate mechanisms generating and constraining individuality in scent identity profiles in banded mongooses. 3. To test our model predictions concerning the factors driving collective investment in group identity formation. 4. To test the causes and consequences of individual variation in contributions to group identity. The experimental findings will feed back to develop extended models which explore the effect of individual heterogeneity on group identity and social behaviour. The project will generate and test a new evolutionary theory of group identity formation which has broad relevance to researchers studying social evolution across taxa, including humans. It will deepen our understanding of the physiological mechanisms driving mammalian scent communication in natural environments, benefiting multiple areas of research in evolution, ecology, and conservation. Finally, the project will provide exceptional training opportunities for researchers in both Uganda and the UK, supporting their development within a dynamic international interdisciplinary team.