Patten, Manus MichaelHaig, David2017-06-092009Patten, Manus M., and David Haig. 2009. “Maintenance or Loss of Genetic Variation Under Sexual and Parental Antagonism at a Sex-Linked Locus.” Evolution 63 (11) (November): 2888–2895. doi:10.1111/j.1558-5646.2009.00764.x. http://dx.doi.org/10.1111/j.1558-5646.2009.00764.x.0014-3820http://nrs.harvard.edu/urn-3:HUL.InstRepos:32970056An intralocus genetic conflict occurs when a locus is selected in opposing directions in different subsets of a population. Populations with two sexes have the potential to host a pair of distinct intralocus conflicts: sexual antagonism and parental antagonism. In this article, we examine the population genetic consequences of these conflicts for X-linked genes. Both conflicts are capable of maintaining genetic variation in a population, but to different degrees. For weak sexual antagonism, the X chromosome has a higher opportunity for polymorphism than the autosomes. For parental antagonism, there is a very limited opportunity for polymorphism on the X chromosome relative to autosomes or to sexual antagonism. X-linkage introduces an asymmetry in the inheritance and expression of sexually and parentally antagonistic genes that leads to a biased fixation of alleles with certain effects. We find little support for the commonly held intuition that the X chromosome should be biased toward fixing female beneficial alleles. Contrary to this intuition, we find that the X chromosome is biased toward fixation of male-beneficial alleles for much of the range of dominance. Additionally, we find that the X chromosome is more favorable to the fixation of alleles that are beneficial when maternally derived.en-USChromosomal evolutiongenetic variationselection—sexualsexual conflictJournal Article10.1111/j.1558-5646.2009.00764.x