Ancestry Correction Hides Selection

Correcting ancient‑DNA analyses for genome‑wide relatedness (GRM/PCs) can absorb historically meaningful ancestry turnover, thereby erasing real population‑level genetic change from the residual time trend. Researchers should report both total temporal change and residual (ancestry‑adjusted) change, test the random‑effect exogeneity assumption, and show within‑ancestry slopes rather than a single corrected coefficient. — This matters because claims that 'no genetic change' occurred over time can be methodological artifacts, and those claims feed public debates about human evolution, ancestry, and the social use of genetics.