A new study of genetic affinity among Jewish communities has uncovered evidence of genetic roots among Jews from North Africa that stretch back 2,000 years.

Some findings are surprising: It turns out that Syrian Jews have more genetic commonality with Ashkenazi (European) Jews than with other oriental Jews (Jews from Asian and African lands).

Also, Yemenite Jews, who have long been thought to have lived in isolation, apparently have genetic connections with people from neighboring states.

Jews of North African origins have greater genetic affinity with Ashkenazi Jews that with non-Jewish residents from North African countries, according to the research study, whose findings were released this week.

The study was conducted at the Albert Einstein College of Medicine at Yeshiva University, in collaboration with Israeli researchers from the Sheba Medical Center, Tel Hashomer, as well as scientists from Columbia and Stanford universities and institutions in France and Spain. The researchers released their findings in the Proceedings of the National Academy of Sciences (PNAS).

Their main claim is the discovery of DNA traces among North African Jews that point to the historic origins of this community. The genetic materials researched in the study indicate two different populations: Jews who migrated to North Africa as a result of the expulsion from Spain and Portugal at the end of the 15th century, and also genes that date back to a more ancient period, over 2,000 years ago, when the first groups of Jews reached North Africa.

The researchers did genetic mapping of 509 Jews whose origins trace back to 15 different communities. The focus was an analysis of Jews of North African ancestry with roots in Morocco, Algeria, Tunisia and Libya. The genetic histories of these persons were compared to those of Jews of European descent, who are rooted in France, Italy, and Russia.

The genetic findings corroborate historical accounts of the history of Jews from North African areas. Jewish migrants were apparently among the first people who established the western settlements of North Africa more than 2,000 years ago. Together with Phoenician merchants, they established the historic city of Carthage, today's Tunis. The most venerable genetic traces uncovered in the study of North African Jews reinforce historical accounts of Jewish settlement under the Ptolemy dynasty in Egypt, in the year 300 BCE.

Researchers believe that Jewish genes traced in the study spread in North Africa via the descendants of mixed couplings, which were common in antiquity. The researchers also detected genetic traces dated from a much later period, around the end of the 15th century; these are attributed to Jewish refugees of the expulsion from Spain and Portugal.

The study findings divided genetic ancestry among North African Jews into two categories - Jews from Tunisia and Libya, and Jews from Morocco and Algeria. Yet Jews in these two groups had genetic affinity with one another, and with Jews from other regions, which exceeds the similarity between their genes and those of non-Jews from the North African states. Prof. Eitan Friedman, director of the Oncogenetics unit at the Sheba Medical Center, and a participant in the study, says: "Jews from North Africa have more in common genetically with other Jews than they do with non-Jewish residents of North Africa, and the study shows generally that Jews everywhere have roots in the Middle East, and these roots are very similar to the genetic roots of Druze. Jewish genetic mingling with other populations is very limited, and Jews preserved their genetic independence for generations."