Coevolution of self-fertilization and inbreeding depression. II. Symmetric overdominance in viability.

Journal Article (Journal Article)

We describe the evolutionary dynamics of a modifier of selfing coevolving with a locus subject to symmetric overdominance in viability under general levels of reduction in pollination success as a consequence of self-fertilization (pollen discounting). Simple models of the evolution of breeding systems that represent inbreeding depression as a constant parameter do not admit the possibility of stable mixed mating systems involving both inbreeding and random mating. Contrary to this expectation, we find that coevolution between a modifier of selfing and a single overdominant locus situated anywhere in the genome can generate evolutionarily attracting mixed mating systems. Two forms of association between the modifier locus and the viability locus promote the evolution of outcrossing. The favored heterozygous genotype at the viability locus develops positive associations with modifier alleles that enhance outcrossing and with the heterozygous genotype at the modifier locus. Associations between outcrossing and high viability evolve immediately upon the introduction of a rare modifier allele, even in the absence of linkage.

Full Text

Duke Authors

Cited Authors

  • Uyenoyama, MK; Waller, DM

Published Date

  • August 1991

Published In

Volume / Issue

  • 40 / 1

Start / End Page

  • 47 - 77

PubMed ID

  • 1948771

Electronic International Standard Serial Number (EISSN)

  • 1096-0325

International Standard Serial Number (ISSN)

  • 0040-5809

Digital Object Identifier (DOI)

  • 10.1016/0040-5809(91)90046-i


  • eng