Kin Recognition and the Major Histocompatibility Complex: An Integrative Review

The major histocompatibility complex (MHC) has been theorized to play a critical role in kin recognition in two contexts, mating and cooperation. Recent work has greatly strengthened this view. The MHC is uniquely important for understanding the evolution of kin recognition because so much is known about its genetics, cell biology, and molecular evolutionary history. Our review integrates recent advances in these fields around the central theme of kin recognition. The chemical cues involved in mammals are controversial and appear to involve microorganisms in some cases. The genes that code MHC glycoproteins, although highly diverse within many species, are similar across generic boundaries in primates and rodents. The potential mechanisms of selection for the incredible allelic diversity at MHC loci are as controversial as ever, but they now also include behavioral mechanisms of disassortative mating and inbreeding avoidance. These studies show how behavior, disease, and molecular genetics can be integrated in a context of evolution and natural selection.