The New York Times tells us that Jewish genetic material runs rampant among Spaniards.
Spain and Portugal have a history of fervent Catholicism, but almost a third of the population now turns out to have a non-Christian genetic heritage. Some 20 percent of the present population of the Iberian peninsula has Sephardic Jewish ancestry, and 11 percent bear Moorish DNA signatures, a team of geneticists reports.
The genetic study, based on an analysis of Y chromosomes, was conducted by a team of biologists led by Mark A. Jobling of the University of Leicester in England and Francesc Calafell of the Pompeu Fabra University in Barcelona.
The biologists developed a Y chromosome signature for Sephardic men by studying Sephardic Jewish communities in places where Jews migrated after being expelled from Spain in 1492-1496. They also characterized the Y chromosomes of the Arab and Berber army that invaded Spain in 711 AD from data on people now living in Morocco and Western Sahara.
Because most of the Y chromosome remains unchanged from father to son, the proportions of Sephardic and Moorish ancestry detected in the present population are probably the same as those just after the 1492 expulsions, assuming no further emigrations since then.
Jonathan S. Ray, a professor of Jewish studies at Georgetown University, said that a high proportion of people with Sephardic ancestry was to be expected. â€œJews formed a very large part of the urban population up until the great conversions,â€ he said.
The genetic analysis is â€œvery compelling,â€ said Jane S. Gerber, an expert on Sephardic history at the City University of New York, and weighs against scholars who have argued there were very few Jewish conversions to Christianity.