The Role of Neanderthals in Human Evolution and Survival
December 13, 2024A detailed genome analysis of ancient modern humans and present-day individuals has refined the timeline of interbreeding between Neanderthals and Homo sapiens, occurring approximately 50,500 to 43,500 years ago. This genetic exchange, lasting about 7,000 years, left Eurasian populations with 1-2% Neanderthal DNA, contributing to immunity, skin pigmentation, and metabolic traits.
The research, based on 58 ancient human genomes and contemporary samples, pinpoints an average interbreeding date of 47,000 years ago, consistent with archaeological evidence. It also underscores the significance of Neanderthal genes in adapting to new environments and surviving Ice Age climates.
The findings challenge prior assumptions of Homo sapiens’ unimpeded migration out of Africa, suggesting that only populations interbreeding with Neanderthals thrived, while others faced extinction. These studies further reveal that environmental factors, rather than human superiority, likely led to Neanderthal extinction.
By analyzing Neanderthal ancestry in detail, researchers identified genome regions devoid of Neanderthal DNA—indicating harmful variants—and high-frequency regions conferring evolutionary benefits. The study highlights how interbreeding shaped modern human success and adaptation.
More information: Leonardo N. M. Iasi et al, Neandertal ancestry through time: Insights from genomes of ancient and present-day humans, Science (2024). DOI: 10.1126/science.adq3010. www.science.org/doi/10.1126/science.adq3010
Arev Sümer, Earliest modern human genomes constrain timing of Neanderthal admixture, Nature (2024). DOI: 10.1038/s41586-024-08420-x. www.nature.com/articles/s41586-024-08420-x
