A groundbreaking study published in Science reveals that Neanderthal males mated with human females far more frequently than the reverse pairing. The research, conducted by an international team of scientists, examined genetic patterns in modern human DNA to reconstruct ancient mating behaviors between the two species.

Modern humans of European and Asian ancestry carry up to 2% Neanderthal DNA from these ancient interbreeding events. The study suggests this mating asymmetry may reflect social preferences rather than random encounters, though researchers acknowledge several biological and behavioral factors could explain the pattern. Population geneticist Benjamin Peter called it "the best attempt trying to get at this question that I have seen."

The findings raise questions about early human social dynamics and competition between species. While some researchers suggest Neanderthal males may have monopolized human females, others point to biological factors that could have made Neanderthal-human offspring less viable when born to Neanderthal mothers. The research provides new insights into how our species interacted with and ultimately replaced Neanderthals across Eurasia.