The promise of medical innovation has long evoked social commentary, particularly when personal reproductiveautonomy may be impacted. Development of the oral contraceptive, effective and safe surgical sterilization, and later IVF and ICSI are among the revolutionary developments where initial reaction was dubious, but eventually, each was accorded mainstream status as clinical experience accumu...

Frequency-dependent selection should drive dioecious populations toward a 1:1 sex ratio, but biased sex ratios are widespread, especially among plants with sex chromosomes. Here, we develop population genetic models to investigate the relationships between evolutionarily stable sex ratios, haploid selection, and deleterious mutation load. We confirm that when haploid selection acts only on the ...

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...