A fascinating compilation of authoritative genetic studies. The final paragraph reads: "New data from recombining genetic markers in the line of Behar et al. (2010), as well as from classical genealogical studies, will surely contribute decisively to explain how this was achieved. At any rate, the DNA evidence gathered so far adds a new facet to the already recognized astonishing cultural resistance of these communities: not only they have kept a sense of belonging throughout centuries of persecution but they also succeeded in maintaining a genetic heritage of their own."