Reference Panels Rewrite Ancestry

An individual’s ancestry proportions against ancient populations can change dramatically depending on which ancient reference samples and modeling choices are used. A '100% Roman' result may reflect the selected Roman/Italic reference set and qpAdm design rather than an unambiguous historical continuity. — This matters because personal ancestry reports can be misread or weaponized in identity and nationalist debates unless the public and journalists understand the model dependence of ancient‑DNA inferences.