A study shows that interbreeding between the two species occurred primarily in one direction, and the origin of this bias is ...

Learn how sex-biased interbreeding between Neanderthals and modern humans explains why Neanderthal DNA is largely missing ...

Human egg cells are often prone to chromosomal errors. As women age, the error rate increases sharply — and can contribute to infertility, pregnancy loss, and ...

Men tend to lose the Y chromosome from their cells as they age. But because the Y bears few genes other than for male determination, it was thought this loss would not affect health. But evidence has ...