Fixation of advantageous alleles in partially self-fertilizing populations: The effect of different selection modes

The expected fixation probability of an advantageous allele was examined in a partially self-fertilizing hermaphroditic plant species using the diffus ion approximation. The selective advantage of the advantageous allele was a ssumed to be increased viability, increased fecundity, or an increase in ma le fitness. The mode of selection, as well as the selfing rate, the populat ion size, and the dominance of the advantageous allele. affect the fixation probability of the allele. In general it was found that increases in selfi ng rate decrease the fixation probability under male sexual selection, incr ease fixation probability under fecundity selection, and increase when rece ssive and decrease when dominant under viability selection. In some cases t he highest fixation probability of advantageous alleles un der fecundity or under male sexual selection occurred at an intermediary selfing rate. The expected mean fixation times of the advantageous allele were also examined using the diffusion approximation.