FEMALE PROMISCUITY IS POSITIVELY ASSOCIATED WITH NEUTRAL AND SELECTED GENETIC DIVERSITY IN PASSERINE BIRDS

• Published in: Evolution Vol. 67; no. 5; pp. 1406 - 1419
• Main Authors: Gohli, Jostein, Anmarkrud, Jarl A., Johnsen, Arild, Kleven, Oddmund, Borge, Thomas, Lifjeld, Jan T.
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01.05.2013; Wiley Subscription Services, Inc; Oxford University Press
• Subjects: Alleles; Animal reproduction; Animals; Balancing selection; Biological variation; Birds; compatible genes; DNA-Binding Proteins - genetics; Evolution; extrapair paternity; Female; Female animals; Gene Frequency; Genes, MHC Class II - genetics; Genetic diversity; Genetic Variation; Introns; Introns - genetics; Male; Mating behavior; Mating Preference, Animal; MHC; pathogen-mediated selection; Pathogens; Promiscuity; Selection, Genetic; Songbirds; Sparrows - genetics; Species diversity; sperm competition
• ISSN: 0014-3820; 1558-5646
• DOI: 10.1111/evo.12045

Passerine birds show large interspecific variation in extrapair paternity rates. There is accumulating evidence that such promiscuous behavior is driven by indirect, genetic benefits to females. Sexual selection theory distinguishes between two types of genetic benefits, additive and nonadditive effects, mediated by preferences for good and compatible genes, respectively. Good genes preferences should imply directional selection and mating skew among males, and thus reduced genetic diversity in the population. In contrast, compatible genes preferences should give balancing selection that retains genetic diversity. Here, we test how well these predictions fit with patterns of variation in genetic diversity and promiscuity levels among passerine birds. We found that more promiscuous species had higher nucleotide diversity at autosomal introns, but not at Z-chromosome introns. We also found that major histocompatibility complex (MHC) class IIB alleles had higher sequence diversity, and therefore should recognize a broader spectrum of pathogens, in more promiscuous species. Our results suggest that female promiscuity targets a multitude of autosomal genes for their nonadditive, compatibility benefits. Also, as immunity genes seem to be of particular importance, we hypothesize that interspecific variation in female promiscuity among passerine birds has arisen in response to the strength of pathogen-mediated selection.