Reference Population Design and the Illusion of Genetic Intermediacy in Mediterranean Population Models

This paper argues that many genetic discussions of Ashkenazi Jewish origins are distorted by reference-population choices. In particular, several influential studies define “Europe” using Northern Italians, Tuscans, Sardinians, and other Northern or Central European groups, while leaving out Southern Italians and Sicilians. When Southern Europe is excluded, Ashkenazi Jews can appear artificially “intermediate” between Europe and the Levant, or shifted toward the Levant, even if the closest modern genetic matches are in Southern Europe. I test this claim using autosomal genetic distance results (FST) and admixture modeling (qpAdm) with Southern European populations included as explicit references. When Southern Italians and Sicilians are properly represented, Ashkenazi Jews show very close affinities to these groups and can be modeled with high-fitting Southern European source frameworks. By contrast, “Europe” defined mainly by Northern Italy and population isolates such as Sardinians can inflate Levant-related distances and encourage misleading interpretations. The contribution is methodological: it shows how proxy selection and incomplete Mediterranean sampling can create a predictable narrative artifact, and it provides a concrete alternative modeling approach that treats Southern Europe as a core reference for Mediterranean population history.