A genetic study of Ashkenazi Jews shows a “whiter” heritage drawn more from prehistoric Europe than from the Levant, home to the modern state of Israel.

A team of international researchers from Malaysia to Salt Lake City found in a study published Tuesday that most variance in mitochondrial DNA — passed from mother to daughter, like Judaism — derives from the indigenous peoples of Western and Central Europe, as opposed to the Levant, as previously thought. Four of the major “founders” of Ashkenazi Jewry derive most variance from European sources, accounting for some 40 percent of the genome. The remaining 60 percent from minor founders, too, comes mostly from Europe.

“These results point to a significant role for the conversion of women in the formation of Ashkenazi communities, and provide the foundation for a detailed reconstruction of Ashkenazi genealogical history,” lead investigator, Martin Richards, and his colleagues wrote. “The origins of Ashkenazi Jews—the great majority of living Jews—remain highly contested and enigmatic to this day.”

Like Sephardic Jews, whose history traces to Iberia, followed by expulsion after 1492, Ashkenazi peoples trace their history to the Levant some 2,000-3,000 years ago. However, researchers suspect Ashkenazi Jews emerged from movements of Mediterranean Jews northward into the Rhineland after the 12th century, later expanding eastward to Poland, Lithuania, and Russia following expulsion from Western Europe in the 14th and 15th centuries.

These massive expansions, some argue, point to widespread conversion to Judaism among women, and men, in these areas, particularly in the North Caucasus region following the adoption by the Khazar kingdom of Judaism.

For years, researchers have pondered the possible genetic admixtures from Europe, the Levant, and the Caucuses, engaging in highly controversial debate. “The extent to which Ashkenazi Jewry trace their ancestry to the Levant or to Europe is a longstanding question,” Richards wrote. “Our results, primarily from the detailed analysis of the four major [genetic] founders, but corroborated with the remaining Ashkenazi [genetics], suggests that most Ashkenazi maternal lineages trace their ancestry to prehistoric Europe.”

Thus, the majority of Ashkenazi genetic heritage derives not from diasporic movement northward from the biblical homeland or from Near Eastern friends, but from within the indigenous peoples of Western and Central Europe.

To reach this conclusion, the researchers sequenced 74 mitochondrial genomes and analyzed more than 3,500 such genomes spanning Europe, the Caucasus, and the Near East, sweeping the entirety of Ashkenazi genealogical history. With some 80 percent of the ancestry deriving from European peoples, Ashkenazi Jews likely began intermarrying with indigenous European women 2,000 years or so ago.

Source: Costa MD, Pereira JB, Pala M, Fernandes V, Olivier A. A Substantial Prehistoric European Ancestry Among Ashkenazi Maternal Lineages. Nature Communications. 2013.