Selection Shifted Modern Polygenic Traits

Using a new test on 15,836 ancient West Eurasian genomes, researchers detect hundreds of loci under directional selection over the past 10,000 years and document population‑scale shifts in combinations of alleles that today predict complex traits (lower predicted body fat and schizophrenia risk; higher predicted cognitive performance). The signals are estimated across 9.7 million variants but were measured against modern GWAS‑based effect maps, so the historic adaptive meaning of the changes is uncertain. — This reframes polygenic‑score debates by showing that many trait‑predictive allele sets are not static background noise but have themselves been the target of recent evolution, affecting how we interpret genetic differences and policy choices about genetic information and reproduction.