Understanding Honey Bee Worker Self-Sacrifice

Abstract

Abstract It is well understood from inclusive fitness theory that genes are important to the evolution of social life. The honey bee Apis mellifera has played a central role as a model of gene discovery, but we do not yet have a full understanding of how genes coordinate worker self-sacrifice and reproductive altruism. In this review, we attempt to bring together what we know from theory regarding any ‘genes for altruism’ that are likely to be present in the honey bee with what we know from practical experiments in molecular biology. First, we highlight an opportunity to bridge the gap between a genetic theory of social evolution that invokes genes in abstraction and the emerging field of sociogenomics that attempts to realize these genes as biochemical molecules that can be characterized, mapped and named. Second, we adopt the kin-theoretic framework of Thompson et al. (2013) to help predict the most likely characteristics of genes underlying altruism. Finally, use this framework as a guide to identify what is known, and not known, about genes that specifically underlie reproductive altruism in honey bees. We show that an integration of theory with genomic tools is useful for identifying genes relevant to social evolution and for testing broader ideas about how social genes are expected to evolve. In our view, this integration has only just begun but the honey bee does provide one starting point from which to push inclusive fitness theory into the age of genomics.