We show that a sex difference in the opportunity for selection results in sex differences in the strength of random genetic drift and thus creates different patterns of genetic diversity for maternally and paternally inherited haploid genes. We derive the effective population size Ne for a male-limited or female-limited haploid gene in terms of I, the “opportunity for selection” or the variance in relative fitness. Because the variance in relative fitness of males can be an order of magnitude larger than that of females, the Ne is much smaller for males than it is for females. We derive both nonequilibrium and equilibrium expressions for FST in terms of I and show how the portion of I owing to sexual selection, Imates, that is, the variation among males in mate numbers, is a simple function of the F's for cytoplasmic (female inherited) and Y-linked (male inherited) genes. Because multiple, transgenerational data are lacking to apply the nonequilibrium expression, we apply only the equilibrium model to published data on Y chromosome and mitochondrial sequence divergence in Homo sapiens to quantify the opportunity for sexual selection. The estimate suggests that sexual selection in humans represents a minimum of 54.8% of total selection, supporting Darwin's proposal that sexual selection has played a significant role in human evolution and the recent proposal regarding a shift from polygamy to monogamy in humans.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.