Some Tuscans can trace their heritage to female ancestors who lived in the same region 5,000 years ago.
Such genetic continuity has been reported in isolated human populations but has rarely been shown in such highly trafficked areas as Tuscany. The region, a corridor of cultural exchange between central Italy and the western Mediterranean coast throughout history, has hosted conquerors from the Romans to Napoleon.
Michela Leonardi at the University of Cambridge, UK, and her colleagues studied mitochondrial DNA, which is inherited only through the maternal line, from modern individuals in northwestern Tuscany. Their analyses identified genetic continuity between modern mitochondrial DNA and remains dating to the region’s prehistoric, Etruscan, Roman and Renaissance eras.
The authors used computer simulations to model evolution of the historical populations involved, estimating population sizes at key times. The simulations compared the effects of genetic continuity and discontinuity for each pair of periods. In each era, genealogical continuity better accounted for the genetic diversity of data the ancient and modern samples.
The authors suggest that the various conquerors might not have brought their womenfolk.