NEANDERTHAL GROWTH HORMONE GENE LINKED TO INCREASED MUSCLE MASS

An international research team has found that a growth hormone receptor inherited from Neanderthals produces significantly larger muscles in people who carry the variant today. Laboratory-grown cells containing the Neanderthal version of the receptor responded 40% more strongly to growth hormone than cells with the more common modern human variant, according to a study published in Current Biology. The research was led by Hugo Zeberg of Karolinska Institutet and Philipp Kanis of the Max Planck Institute for Evolutionary Anthropology. The team identified two genetic changes in the Neanderthal receptor not present in the dominant modern human version, with one change accounting for most of the stronger response.

Modern humans acquired this receptor variant through interbreeding with Neanderthals approximately 47,000 years ago. The variant is now distributed unevenly across global populations, with up to 24% of people in some South Asian populations carrying it, compared with around 0.5% of Europeans. Analysis of body measurements from more than 6,000 children revealed no association between the Neanderthal variant and growth during childhood, suggesting the muscular effects emerge only after that period. Data from more than one million individuals showed signs of the same effect observed in laboratory conditions, according to the research team.

The findings demonstrate that genetic legacies from Neanderthals continue to shape human physiology. Philipp Kanis noted that laboratory evidence and large-scale population data converged to support the same conclusion, providing unusually clear alignment between controlled experiments and real-world observations. The research contributes to growing understanding of how interbreeding between modern humans and Neanderthals influenced traits in contemporary populations.