Overview
- The Nature paper, which appeared Friday, analyzed nearly 16,000 ancient genomes from West Eurasia and identified 479 variants shaped by directional selection.
- A large time series and new computational tools let researchers track allele changes through time and filter out effects from migration, mixing, and random drift.
- Signals of selection strengthened after the shift to farming about 10,000 years ago, reflecting new diets, denser living, and fresh disease pressures.
- One highlighted case is the CCR5-Δ32 allele, which increased between roughly 6,000 and 2,000 years ago, and many other signals map to traits such as skin tone and disease risk.
- The authors report these signals account for about 2% of total gene-frequency change and note the findings reflect West Eurasian samples, pointing to a need for ancient DNA from other regions.