Genetic study traces Jewish descent

Stepping into the contentious world of race, ethnicity and genetics, a paper published in this week's Nature claims to have shed new light on the geographical origin of the many 'Jewish Diaspora' communities from around the world. This term is used to describe the distribution of established Jewish communities across the globe resulting from migrations from the Middle East to Europe, Africa and Asia.

Much genetic research has been conducted on the origins of the Jewish community and the prevalence of genetic conditions in this community, according to the Nature paper. However, it explains, researchers have been acutely aware of the ethno-cultural, genetic and religious complexity of the Jewish demographic, which means that the genetic structure of the Jewish population is difficult to investigate.

Against this backdrop, an international team of scientists from Israel, Europe, Russia and the US conducted a genome-wide association study (GWAS) of the genetic variation across Jewish communities and their non-Jewish neighbours. The genes of 121 people from 14 Jewish communities were analysed and compared 1,166 people to 69 non-Jewish populations, including ones from Jewish Diaspora areas as well as from the Middle East and North Africa.

The study revealed a close genetic relationship between contemporary Jewish and non-Jewish populations from the Levant region, in particular Cypriot and Druze groups. Druze are a religious community in Syria, Lebanon, Israel and Jordan which consider themselves 'an Islamic Unist, reformatory sect'. This finding fits the theory that most Jewish communities are descended from ancient Hebrew and Israelite residents of the Levant.

The Levant is described as 'the crossroads of western Asia, eastern Mediterranean and northeast Africa', which includes Lebanon, Israel, Palestine, Syria, Jordan, Cyprus, Sinai and part of Iraq (Institute of Archaeology, London).

The team also found a previously-unrecognised genetic structure that clearly partitions Jewish Diaspora communities from each other and the people in the surrounding non-Jewish communities, which they speculated could be due to the splintering of the groups during migration, as well as the mixing of different communities in these areas. 

In contrast, Ethiopian and Indian-Jewish communities have strong genetic similarities to their neighbouring communities, which again the authors suggested was the result of 'religious and cultural diffusion during the process of becoming one of the many and varied Jewish communities'.