Tue May 13 00:00:00 UTC 2025: ## Neanderthal Genes Gave East Asians Lactose Tolerance, Challenging Evolutionary Theory
**Shanghai, China/Leipzig, Germany – May 13, 2025** – A new study published in the *Proceedings of the National Academy of Sciences* challenges the long-held belief that lactose tolerance in humans evolved solely through the co-evolution of genes and culture. Researchers from Fudan University, the Max Planck Institute, and the Université de Lyon have discovered that East Asian populations acquired lactase persistence – the ability to digest lactose in adulthood – through a unique evolutionary pathway involving Neanderthal genes.
The prevailing theory posited that the emergence of lactase persistence in Europeans and Africans coincided with the domestication of livestock around 11,000 years ago. This “convergent evolution” was seen as a textbook example of cultural practices (consuming milk) driving genetic adaptation.
However, this new research reveals a different story for East Asians. Genetic analysis suggests that the lactase persistence gene in this population originated from Neanderthals and underwent selection pressures beginning over 30,000 years ago – millennia before livestock domestication in the region. This suggests that the selective advantage conferred by this gene was not directly related to lactose digestion, but possibly to other factors, potentially immunological. Analysis of ancient DNA from the Amur region of China further supports this pre-agricultural selection. The frequency of the Neanderthal-derived lactase gene increased gradually over time, reaching about 29% in modern East Asian populations.
This finding complicates the simple narrative of gene-culture co-evolution, suggesting that the evolutionary path to lactase persistence varied across different human populations. The researchers note that further research is needed to fully understand the complex interplay of genetic inheritance and environmental pressures in shaping human adaptation.
First Piper 