Assortative mating can impede or facilitate fixation of underdominant alleles

Newberry, M. G., McCandlish, D. M., Plotkin, J. B. (December 2016) Assortative mating can impede or facilitate fixation of underdominant alleles. Theor Popul Biol, 112. pp. 14-21. ISSN 1096-0325 (Electronic)0040-5809 (Linking)

DOI: 10.1016/j.tpb.2016.07.003


Underdominant mutations have fixed between divergent species, yet classical models suggest that rare underdominant alleles are purged quickly except in small or subdivided populations. We predict that underdominant alleles that also influence mate choice, such as those affecting coloration patterns visible to mates and predators alike, can fix more readily. We analyze a mechanistic model of positive assortative mating in which individuals have n chances to sample compatible mates. This one-parameter model naturally spans random mating (n=1) and complete assortment (n-->infinity), yet it produces sexual selection whose strength depends non-monotonically on n. This sexual selection interacts with viability selection to either inhibit or facilitate fixation. As mating opportunities increase, underdominant alleles fix as frequently as neutral mutations, even though sexual selection and underdominance independently each suppress rare alleles. This mechanism allows underdominant alleles to fix in large populations and illustrates how life history can affect evolutionary change.

Item Type: Paper
Uncontrolled Keywords: Best-of- Diffusion Hardy-Weinberg equilibrium Heterosis Mate choice Slow manifold
Subjects: bioinformatics > genomics and proteomics > genetics & nucleic acid processing
CSHL Authors:
Communities: CSHL labs > McCandlish lab
Depositing User: Matt Covey
Date: December 2016
Date Deposited: 18 Jan 2017 21:27
Last Modified: 08 Jul 2021 15:26
PMCID: PMC5642052
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