NEW YORK: A new genetic analysis has reconstructed the history of North Africa's Jews, showing that these populations date to biblical-era Israel and are not largely the descendants of natives who converted to Judaism, scientists reported on Monday.
The study also shows that these Jews form two distinct groups, one of which is more closely related than the other to their European counterparts, reflecting historical migrations.
The findings are the latest in series of genetic studies, which began in the 1990s, indicating that the world's Jews share biological roots, not just cultural and religious ties. In many cases the analyses have confirmed what scholars had gleaned from archaeological finds and historical accounts.
"This work demonstrates a shared genetic history among the Jews of North Africa and strengthens the case for a biological basis for Jewishness," said medical geneticist Harry Ostrer of the Albert Einstein College of Medicine in New York, who led the study.
For the new analysis, published in the Proceedings of the National Academy of Sciences, Ostrer and his colleagues examined the genomes of 509 Jews and 11 non-Jews from North Africa, which is home to the second-largest Jewish diaspora. Only the European diaspora, which includes American Jews, is larger.
The scientists found that the Jewish populations of North Africa became genetically distinct over time, with those of each country carrying their own DNA signatures. That suggests they mostly married within their own religious and cultural group, said Ostrer. "They lived in ghettos," he said, "so their mobility was quite restricted, and by marrying each other they became as closely related as first cousins once removed."
The analysis showed that all North African Jews are descended from forebears in the Middle East, supporting the hypothesis that biblical-era Israelites among Phoenician traders established colonies along the North African coast.
Common DNA signatures also show that some groups are closer, genetically, to their European co-religionists than expected. That suggests "a shared set of founders," said Ostrer, presumably Jews from the Middle East who migrated west.
If Jewish populations in North Africa and Europe shared ancestors, then Sephardic Jews who settled in Africa after being expelled from Spain during the Inquisition originated in North Africa more than 1,000 years earlier. "The Sephardic Jews show significant North African ancestry," said Ostrer. "That could reflect bidirectional migrations" to and from North Africa and Europe over the centuries.