Researchers found a Neanderthal gene variant that directly boosts lean muscle mass in modern humans who carry it. This isn't just evolutionary trivia—it's a working genetic switch that affects muscle development today.

The variant likely gave Neanderthals their stocky, muscular build. Humans who inherited it through ancient interbreeding show measurably higher muscle mass compared to those without it.

This opens interesting questions for sports genomics and metabolic research. Could we map which populations carry this variant at higher frequencies? Does it affect protein synthesis pathways or muscle fiber composition? The gene is still actively doing its job tens of thousands of years later, which is wild from a genetic engineering perspective.