The genes of attraction: Mating behavior, immunogenetic variation, and parasite resistance

Abstract Mate choice for indirect (genetic) benefits is puzzling because as sexual selection for “good genes” whittles away genetic variation in the population, the incentive to be choosy also disappears. One solution to this problem is that genetic variation could be maintained by natural selection imposed by continuously coevolving parasites. Indeed, immune genes are likely the best candidates for “good genes” models of mate choice as some of the most polymorphic regions in animal genomes are involved in immune defense against parasites and pathogens. This chapter reviews the theoretical prerequisites for immune genes to be involved in mate choice and discusses the mechanisms by which mate choice may act on immunogenetic variation. Through a systematic literature search it then identifies and summarizes examples of sexual selection acting on immune genes from across both vertebrate and invertebrate systems. Finally, this chapter identifies some of the important contextual factors that can complicate their discovery and lays out the challenges to testing the generality of this phenomenon.