Common Genetic Threads Link Thousands of Years of Jewish Ancestry





Using sophisticated genomic analysis, scientists have probed the ancestry of several Jewish and non-Jewish populations and better defined the relatedness of contemporary Jewish people. The research, published in the June issue of the American Journal of Human Genetics, may shed light on the question, first raised more than a century ago, of whether Jews are a race, a religious group or something else.

The genetic, cultural and religious traditions of contemporary Jewish people originated in the Middle East over three thousand years ago. Since that time, Jewish communities have migrated from the Middle East into Europe, North Africa and across the world. The migration of Jews to new locales is known as the Diaspora. This study shows that although Jewish people experienced genetic mixing with surrounding populations, they retained a genetic coherence along with a religious one.

To better understand the relatedness of current Jewish groups, Dr. Ostrer and colleagues performed a genome wide analysis of Iranian, Iraqi, Syrian, Italian, Turkish, Greek and Ashkenazi Jews and compared these results with non-Jewish groups. The researchers identified distinct Jewish population clusters that each exhibited a shared Middle Eastern ancestry, proximity to contemporary Middle Eastern populations and variable degrees of European and North African genetic intermingling.

The history of Jewish people could be found in their genomes. The two major groups, Middle Eastern Jews and European Jews, were timed to have diverged from each other approximately 2500 years ago. Southern European populations show the greatest proximity to Ashkenazi, Sephardic and Italian Jews, reflecting the large-scale southern European conversion and admixture known to have occurred over 2,000 years ago during the formation of the European Jewry. An apparent North African ancestry component was also observed as was present in the Sephardic groups potentially reflecting gene flow from Moorish to Jewish populations in Spain from 711 to 1492. The structure of the genomes of Ashkenazi Jewish populations indicates a severe bottleneck followed by expansion during the 19th century when the Jewish population in western and eastern Europe increased about twice as fast as the non-Jewish population. This has been referred to as "the demographic miracle." Within every Jewish group, there was a high degree of relatedness between any two of its members. For Ashkenazi Jews, the relatedness was similar to what one might observe for fifth cousins.


comments powered by Disqus
History News Network