BACKGROUND Preconception sex selection for non-medical reasons is a controversial issue in bioethics. Little research has described preferences for preconception sex selection among Arab populations. This study describes the sex preference and interest in employing sex selection techniques among pregnant women in northern Jordan. METHODS A self-reported questionnaire was administered to 600 p...

Some animal groups, such as birds, seem prone to extreme forms of sexual selection. One contributing factor may be sex linkage of genes affecting male displays and female preferences. Here we show that sex linkage can have substantial effects on the genetic correlation between these traits and consequently for Fisher's runaway and the good-genes mechanisms of sexual selection. Under some kinds ...

We model parental sex selection and the equilibrium sex ratio. With intrinsic son preference, sex selection results in a male-biased sex ratio. This is ine¢ cient, due to a marriage market congestion externality. Medical innovations that facilitate selection increase ine¢ ciency. If son preference arises endogenously, due to population growth causing an excess of women on the marriage market, s...

Simulations of the evolution of populations of diploid organisms showed that mate selection strategies which selected for “good genes” and strategies based on assortative mating, confer a much higher average fitness and higher evolutionary stability to populations than random mating. This advantage was more conspicuous the more genes per organism were simulated and the more genes were involved ...

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Theory suggests that sex-specific selection can facilitate adaptation in sexually reproducing populations. However, sexual conflict theory and recent experiments indicate that sex-specific selection is potentially costly due to sexual antagonism: alleles harmful to one sex can accumulate within a population because they are favored in the other sex. Whether sex-specific selection provides a net...