Portuguese Jews after Inquisition: genetics and self-awareness
Crypto-Judaism, stricto senso, is defined as the secret adherence to Judaism while publicly professing another faith. A general outcome of religious intolerance, it has been more specifically associated with Iberian Inquisition, both in Europe and in Portuguese and Spanish colonies overseas. As for Portugal it was with surprise that the scientific world acknowledged the persistence of the phenomenon at the beginning of the 20th century in some small communities in central and north-eastern regions of the country (e.g. Belmonte, Bragança, Miranda, and Chaves).
The strong sense of a Jewish root is still now well alive. Due to a constellation of well known historical events, Jewish populations are a paradigm of constantly migrating communities. In our work we aim to focus at a specific subset of these complex movements, namely the fate of the 16th century Iberian Jewish communities. Iberian Jews were at that time, a demographically non-negligible minority that suddenly was forced to either conversion or expulsion. We intend to use genetic markers typed in extant populations to infer the demographic history of the communities that stayed in Iberia (the so-called crypto-Jews) and of those that have migrated to Northern Europe and the New World. Our first results on paternal lineages as well as on the maternal side concur to show that the communities scattered over the Bragança district have succeeded in maintaining a high level of genetic diversity and a genetic profile distinct from the host population with a clear root in the Near East. These findings are extremely surprising, as they show exactly the opposite of what is expected in isolated, small sized populations, namely a deep genetic diversity loss.