Evolution of Inbreeding Avoidance and Inbreeding Preference through Mate Choice among Interacting Relatives

Authored by Jane M Reid, A Bradley Duthie

Date Published: 2016

DOI: 10.1086/688919

Sponsors: Royal Society European Research Council (ERC)

Platforms: C

Model Documentation: Other Narrative Mathematical description

Model Code URLs: http://datadryad.org/resource/doi:10.5061/dryad.3861f

Abstract

While extensive population genetic theory predicts conditions favoring evolution of self-fertilization versus outcrossing, there is no analogous theory that predicts conditions favoring evolution of inbreeding avoidance or inbreeding preference enacted through mate choice given obligate biparental reproduction. Multiple interacting processes complicate the dynamics of alleles underlying such inbreeding strategies, including sexual conflict, distributions of kinship, genetic drift, purging of mutation load, direct costs, and restricted kin discrimination. We incorporated these processes into an individual-based model to predict conditions where selection should increase or decrease frequencies of alleles causing inbreeding avoidance or inbreeding preference when females or males controlled mating. Selection for inbreeding avoidance occurred given strong inbreeding depression when either sex chose mates, while selection for inbreeding preference occurred given very weak inbreeding depression when females chose but never occurred when males chose. Selection for both strategies was constrained by direct costs and restricted kin discrimination. Purging was negligible, but allele frequencies were strongly affected by drift in small populations, while selection for inbreeding avoidance was weak in larger populations because inbreeding risk decreased. Therefore, while selection sometimes favored alleles underlying inbreeding avoidance or preference, evolution of such strategies may be much more restricted and stochastic than is commonly presumed.

Tags

Pollen limitation Mating systems Population-size Sex-biased dispersal Self-fertilization Inclusive fitness Kin-recognition Genetic load No evidence Joint evolution