A Neanderthal Gene May Be Making Some Modern Humans Bigger and More Muscular

A Neanderthal gene may be making some modern humans bigger and more muscular, according to new research. The study found that a growth hormone receptor inherited from Neanderthals was present in southeast Asian populations and showed a 40% increase in cell proliferation in laboratory experiments. The variant was concentrated in South Asia, with approximately 24% of people in some populations carrying it, compared to 0.5% in Europeans. The research suggests that this genetic variant may influence muscle growth and body size in modern humans.

The study's findings are supported by both laboratory experiments and real-world population data. Carriers of the Neanderthal-derived variant had approximately 270 additional grams of muscle mass on average. The researchers note that the effects of the receptor likely emerge after age 11, as growth hormone levels increase during puberty. The study also found that the variant is associated with shorter tooth roots and differences in jaw shape, which are features commonly seen in Neanderthal remains.

The study highlights the convergence of two lines of evidence: laboratory experiments and population data. The findings suggest that a genetic change from Neanderthals can still influence human body size and muscle mass today. However, the researchers emphasize that this is just one of many genetic influences on growth and body shape. The paper, "Increased Signaling of the Neanderthal Growth Hormone Receptor," was published in Current Biology on August 5, 2026.

AI-generated summary of the original article — see the source for the full story.