Red hair may be increasing as study points to surprising evolution trend

Key Points:

• A Harvard Medical School study analyzing 16,000 ancient genomes over 10,000 years found that natural selection favored the genetic variants for red hair, suggesting an increase in redheaded individuals as humans evolve.
• The research identified 479 gene variants, including those for red hair, that have been strongly selected during the transition to farming, which caused significant environmental and behavioral changes accelerating human evolution.
• The study provides the first definitive statistical evidence that red hair was actively selected during the rise of agricultural societies, though the exact prehistoric benefits remain unclear, with vitamin D synthesis hypothesized as a possible factor.
• Researchers caution that the current associations of genetic traits may not reflect the original reasons for their evolutionary advantage, emphasizing the need for further study to understand the historical context of these gene selections.
• This work expands the known instances of directional selection in humans from about 21 to hundreds, offering new insights into how natural selection has shaped human biology in real time.