The genetics of sex-ratio variation have important implications for the evolution of the sex ratio for two reasons. First, additive genetic variance is required for the evolution of any trait, ...

Ray and colleagues1 present data on variation in birth sex ratios among Ontario newborns, showing a significant male-biased sex ratio at birth among multiparous Indian and South Korean mothers. The ...

A study finds natural variation in baseline sex ratios at birth and evidence of sex ratio inflation in 12 countries. Prevalence of sex-selective abortion in some countries can skew the sex ratio at ...

Sex ratio has been studied from many theoretical and empirical perspectives, but a general assumption in sex ratio research is that changes in sex ratio occur because of selection on sex ratio itself.

An international team of researchers, led by UMass Amherst biostatistician Leontine Alkema and her former Ph.D. student Fengqing Chao, developed a new estimation method for assessing natural ...