09 June 2010

DNA: Wandering Jews' common origin

Two major Jewish DNA studies confirm that Jewish diaspora communities maintained strong DNA links despite thousands of years of separation from their Middle East origins.

Both studies refute countercaims on Jewish origins, such as Shlomo Sand's suggestion in his book, "The Invention of the Jewish People." Sand claims that Jews have no origin in common but are various peoples in Europe and Central Asia who converted to Judaism in the past.

The two studies are that of Gil Atzmon (Albert Einstein College of Medicine) and Harry Ostrer (New York University), in the American Journal of Human Genetics; and that of Doron M. Behar (Rambam Health Care Campus, Haifa, Israel) and Richard Villems (University of Tartuin, Estonia), in Thursday’s edition of Nature.

While many have already commented on the first study, I've been waiting to receive the full article which has just arrived. Reading the various articles based on the Ostrer study leads me to believe that not all writers read the complete report.

I'm also expecting the new full report today, headed by molecular geneticist Dr. Doron M. Behar of Haifa, Israel. Doron has spoken to the Jewish Family Research Association genealogical study several times on his previous work. He is also the chief scientist for FamilyTreeDNA.com.

According to the new report's abstract:
Contemporary Jews comprise an aggregate of ethno-religious communities whose worldwide members identify with each other through various shared religious, historical and cultural traditions. Historical evidence suggests common origins in the Middle East, followed by migrations leading to the establishment of communities of Jews in Europe, Africa and Asia, in what is termed the Jewish Diaspora. This complex demographic history imposes special challenges in attempting to address the genetic structure of the Jewish people. Although many genetic studies have shed light on Jewish origins and on diseases prevalent among Jewish communities, including studies focusing on uniparentally and biparentally inherited markers, genome-wide patterns of variation across the vast geographic span of Jewish Diaspora communities and their respective neighbours have yet to be addressed.
Individuals from 14 Jewish Diaspora communities were compared with those from 69 Old World non-Jewish populations - 25 had not been reported previously. The Jewish and non-Jewish populations in the Diaspora, as well as non-Jewish populations from the Middle East and north Africa, were compared.

According to an AFP story:
"We found evidence that Jewish communities originated in the Near East," said molecular scientist Doron Behar of the Rambam Health Care Campus in Haifa, Israel, who led an investigation gathering experts in eight countries.

"Our genetic findings are concordant with historical records."

The work entailed taking DNA samples from 121 people living in 14 Jewish communities around the world, ranging from Israel to North Africa and Europe to Central Asia and India.

The samples were then compared with those from 1,166 individuals in 69 non-Jewish populations, including the "host" country or region where there was a Jewish community.

Throwing another dataset into the mix, the researchers added analyses of 16,000 samples of the Y chromosome -- which only males have -- and of mitochondrial DNA, which is handed down through the maternal line.
The scientists were looking for combinations of markers called single nucleotide polymorphisms, called SNPs for short.

SNPs are single changes in the genome that cluster in distinctive patterns among humans that live together in groups over thousands of years. The patterns are a useful pointer of how ethnicities developed through geographical isolation or social clustering.
The study confirmed Middle Eastern (Levantine) origins of Jews as documented in ancient Hebrew scriptures. The lineage is clearly seen in today's Jewish communities today, thousands of years after the Jews were expelled or exiled from Israel.

One surprising discovery was that Jewish SNPs were closer to Cypriots and Druze than with other Middle Eastern populations.

Diaspora Jews, tightly bound by social, cultural and religious traditions, have generally maintained a strong genetic continuity, although there has also been an induction of DNA to greater or lesser degree from the host population, the paper said.

"Jewish communities seem to have a continuity with the Levantine gene pool, but even with the Jewish communities, you still see how they tend towards the host population," said Behar.
Behar said he would be dismayed if the research added to genetic profiling - such as the politically-charged "Who is a Jew? debate. Each time he has spoken to JFRA in Israel he stresses that genetics has nothing to do with the definition of Jewish identity, and that anyone can convert to Judaism. Genetics in that case could not prove or disprove someone's Jewish identity.

The New York Times' Nicholas Wade produced a great story on both these important studies:
Jewish communities in Europe and the Middle East share many genes inherited from the ancestral Jewish population that lived in the Middle East some 3,000 years ago, even though each community also carries genes from other sources — usually the country in which it lives.

That is the conclusion of two new genetic surveys, the first to use genome-wide scanning devices to compare many Jewish communities around the world.

A major surprise from both surveys is the genetic closeness of the two Jewish communities of Europe, the Ashkenazim and the Sephardim. The Ashkenazim thrived in Northern and Eastern Europe until their devastation by the Hitler regime, and now live mostly in the United States and Israel. The Sephardim were exiled from Spain in 1492 and from Portugal in 1497 and moved to the Ottoman Empire, North Africa and the Netherlands.
The two studies refute historian Shlomo Sand's suggestion in his book, "The Invention of the Jewish People," that Jews have no origin in common but are various peoples in Europe and Central Asia who converted to Judaism in the past.

Jewish communities from Europe, the Middle East and the Caucasus all have substantial genetic ancestry that traces back to the Levant; Ethiopian Jews and two Judaic communities in India are genetically much closer to their host populations.
Atzmon and Ostrer's calculations show that Iraqi and Iranian Jews were separated from other Jewish communities about 2,500 years ago, reflecting the Babylonian Exile following the destruction of Jerusalem's First Temple.

The study indicates that members of any Jewish community are as close as fourth or fifth cousins in a large population. That is, according to Atzmon, 10 times higher than the relationship between any two randomly chosen people on the streets of New York City.

When it comes to the Sephardic and Ashkenazi dichotomy, the study shows that both show roughly 30% European ancestry, with the rest from the Middle East. Despite the long separation of these two communities, they are very similar genetically.

One explanation is that they come from the same Jewish source population in Europe. The Atzmon-Ostrer team found that the genomic signature of Ashkenazim and Sephardim was very similar to that of Italian Jews, suggesting that an ancient population in northern Italy of Jews intermarried with Italians could have been the common origin. The Ashkenazim first appear in Northern Europe around A.D. 800, but historians suspect that they arrived there from Italy.

Another explanation, which may be complementary to the first, is that there was far more interchange and intermarriage than expected between the two communities in medieval times.

Stanford University Sephardic historian Aron Rodrigue says that historians have noticed a trend indicating more contact between Ashkenazim and Sephardim than previously suspected.

A common surname among Italian Jews is Morpurgo, meaning someone from Marburg in Germany. Also, Dr. Rodrigue said, one of the most common names among the Sephardim who settled in the Ottoman Empire is Eskenazi, indicating that many Ashkenazim had joined the Sephardic community there.
Do read the complete articles and abstracts on both studies for more information. Harry Ostrer will be speaking at the 30th IAJGS International Conference on Jewish Genealogy, in Los Angeles, from July 11-16.


  1. Why am I not surprised that the studies showed a closeness between Ashkenazi and Sephardic Jews?

    Our Iberian Ashkenaz Y-DNA project has shown that many Ashkenazi males have Sephardic ancestry on their paternal line, including those in Y- haplogroups that were previously thought to be central Asian.

    I bet there was more interchange between the Ashkenazi and Sephardic populations than Jewish genealogists previously thought.

    Judy Simon

  2. Luciano Morpurgo2:59 PM

    Just a small correction: the origin of the italian name Morpurgo doesn't come in fact from Marburg, Germany, but from Marburg, Styria (now Maribor, Slovenia):

    Thus it can't be taken as an example of "contact" between Ashkenazim and Sephardim in northern Italy.
    Best regards,
    Luciano Morpurgo