Grant: Discovery Grants Program - Individual

One of the most important puzzles in evolutionary biology concerns the evolution of altruism, a behaviour in which an individual sacrifices its own reproduction in order to help other individuals reproduce. How do the genes underlying altruistic behaviour spread through populations when altruists leave fewer genes to subsequent generations than do the individuals that they help? Usually this conundrum is solved by invoking kin selection, in which altruistic individuals sacrifice personal reproduction, but more than make up for it by raising close relatives which share their genes. However, empirical studies of primitively social bees, those in which females have the potential to behave as altruists or to produce their own offspring, provide evidence that subordinate females frequently pass on fewer genes by behaving altruistically than they would have if they produced their own brood. This suggests that kin selection does not provide a complete explanation for altruistic behaviour. My research proposal will focus on multiple aspects of the social behaviour of carpenter bees (Xylocopa and Ceratina) and sweat bees (Lasioglossum), in which potential helpers have the potential to breed themselves; when they behave as altruists we can then examine the ecological and evolutionary conditions that promote this behaviour. Our research will incorporate field and laboratory techniques, including tracing patterns of maternity within bee colonies using genetic markers. At the broadest level, detailed field studies of behaviour, demography and ecology will uncover the conditions under which individual bees choose to behave altruistically or selfishly, as well as the consequences of these decisions for colony social organisation.