A recent genetic study suggests that Neanderthals may have predominantly inherited modern human DNA from the females in their population, attributed to probable mate preference differences between Neanderthal men and women. Researchers from the University of Pennsylvania reached this conclusion by analyzing the presence of “anatomically modern human” (AMH) and Neanderthal DNA in the X chromosomes of Neanderthals. This study, published in the journal Science, offers insights into the social dynamics of ancient populations.
Modern humans originated in Africa, while Neanderthals inhabited Europe and Asia, leading to interbreeding between the two groups and the transmission of genetic material. The genetic mixing resulted in the presence of Neanderthal DNA in the genomes of non-African human ancestors. The study focused on the unequal distribution of human DNA in Neanderthal X chromosomes, which showed significantly more human genetic material compared to other chromosomes.
The researchers examined the X chromosomes of ancient Neanderthal women and modern human women from sub-Saharan Africa. They discovered that Neanderthal women exhibited a higher proportion of human DNA on their X chromosomes, suggesting potential reasons for this genetic pattern. One hypothesis proposed that human genes on the X chromosome outperformed Neanderthal genes, leading to their replacement. However, the study found that the additional human DNA was located in non-functional genomic regions.
Another explanation suggested that mating preferences favored individuals with more Neanderthal or human ancestry, resulting in differing genetic contributions to the X chromosome due to the transmission patterns of this chromosome by women. The researchers explored various scenarios to explain this unequal genetic distribution and its implications on mate preferences among Neanderthals.
The study also considered other factors such as migration patterns, natural selection, and potential impacts on offspring health. Previous research indicated challenges in Neanderthal-human hybrid pregnancies and fertility, influencing mating choices and genetic compatibility. These findings shed light on the complex interactions between ancient populations and their genetic legacies, highlighting the intricate dynamics of interbreeding between Neanderthals and modern humans.