Dispersal alters the nature and scope of sexually antagonistic variation
File(s)
Working paper
Author(s)
Flintham, Ewan
Savolainen, Vincent
Mullon, Charles DL
Type
Working Paper
Abstract
Intra-locus sexual conflict, or sexual antagonism, occurs when alleles have opposing fitness effects in thetwo sexes. Previous theory suggests that sexual antagonism is a driver of genetic variation by generating bal-ancing selection. However, these studies assume that populations are well-mixed, neglecting the effects ofspatial subdivision. Here we use mathematical modelling to show that limited dispersal can fundamentallychange evolution at sexually antagonistic autosomal and X-linked loci due to inbreeding and sex-specific kincompetition. We find that if the sexes disperse at different rates, kin competition within the philopatric sexbiases intralocus conflict in favour of the more dispersive sex. Furthermore, kin competition diminishes thestrength of balancing selection relative to genetic drift, reducing genetic variation in small subdivided pop-ulations. Meanwhile, by decreasing heterozygosity, inbreeding reduces the scope for sexually antagonisticpolymorphism due to non-additive allelic effects, and this occurs to a greater extent on the X-chromosomethan autosomes. Overall, our results demonstrate that spatial structure is an important factor in predictingwhere to expect sexually antagonistic alleles. We suggest that observed interspecific and intragenomic varia-tion in sexual antagonism may be explained by sex-specific dispersal ecology and demography.
Date Issued
2020-05-07
Citation
2020
Publisher
BioRxiv
Copyright Statement
The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-NC 4.0 International license.