Confronted by the violence sweeping over Israel, it can be easy to overlook the things that Jews and Palestinians share: a deep attachment to the same sliver of contested land, a shared appetite for hummus, a common tradition of descent from the patriarch Abraham, and, as scientific research shows - a common genetic ancestry, as well.

Several major studies published in the past five years attest to these ancient hereditary links. At the forefront of these efforts are two researchers: Harry Ostrer, professor of pediatrics and pathology at Albert Einstein College of Medicine in the Bronx, New York, and Karl Skorecki, director of medical and research development at the Rambam Health Care Campus in Haifa. Back in June 2010, and within two days of each other, the two scientists and their research teams published extensive analyses of the genetic origins of the Jewish people and their Near East ancestry.

“The closest genetic neighbors to most Jewish groups were the Palestinians, Israeli Bedouins, and Druze in addition to the Southern Europeans, including Cypriots,” as Ostrer and Skorecki wrote in a review of their findings that they co-authored in the journal Human Genetics in October 2012.

“Karl and I are good friends,” Ostrer told Haaretz by telephone from New York. “We used somewhat different analytical methods—there’s no claim there for superiority, or one side versus the other.” In their results, as well, “there was really very little difference at all.”

Ostrer’s research on “Abraham’s Children in the Genome Era,” published in The American Journal of Human Genetics, sampled 652,000 gene variants from each of 237 unrelated individuals from seven Jewish populations: Iranian, Iraqi, Syrian, Italian, Turkish, Greek and Ashkenazi. These sequences were then compared with reference samples from non-Jews drawn from The Human Genome Diversity Project, a global database of genetic information gathered from populations across the world.

Each of the Jewish populations, they found, “formed its own distinctive cluster,” indicating their shared ancestry and “relative genetic isolation.”

Ostrer’s team also identified two major groups of Jews: Middle Eastern Jews (Iranian and Iraqi) and European/Syrian Jews. The split between these two groups of Jews occurred some 2,500 years ago.

Cousins with the Druze and French

Both groups of Jews shared ancestry with contemporary Middle Eastern and Southern European populations. The closest genetic relatives of the Middle Eastern Jews are Druze, Bedouin and Palestinians. The closest genetic relatives of the European group of Jews are Northern Italians, followed by Sardinians and French.

In a 2012 study, Ostrer identified North African Jews as a third major group. In Skorecki’s study on the genome-wide structure of the Jewish people, published in the journal Nature, he and his fellow researchers sampled tens of thousands of genetic variants from the genomes of 121 individuals hailing from 14 Jewish Diaspora communities, and compared these variants with samples drawn from 1,166 individuals from 69 Old World non-Jewish populations.

They found that Jews from the Caucasus (Azerbaijan and Georgia), the Middle East (Iran and Iraq) North Africa (Morocco) and Sephardi and Ashkenazi communities, as well as Samaritans, form a “tight cluster” that overlaps with Israeli Druze.

This, the authors write, “is consistent with an ancestral Levantine contribution to much of contemporary Jewry.”

In addition, a “compact cluster” of Yemenite Jews “overlaps primarily with Bedouins but also with Saudi individuals.” Ethiopian and Indian Jews are more closely related to their own neighboring, host populations.

Middle East origins in European Jews

Further evidence for the Middle Eastern origins of Ashjenazi Jews came from a study published in 2014: In that research, which appeared in Nature Communications, a team led by Shai Carmi of the Hebrew University of Jerusalem sequenced the complete genomes of 128 people of Ashkenazi Jewish ancestry. Their analysis revealed that the Ashkenazi Jewish population is “an even mix” of European and Middle Eastern ancestral populations—suggesting, as Carmi writes on the web site of The Ashkenazi Genome Consortium (TAGC), “a sex-biased process, where, say, Middle-Eastern Jewish men married European non-Jewish women.”

Are these genetic ties between Jews, Palestinians, Bedouin, and Druze important in a contemporary context? “It doesn’t matter to me personally,” Skorecki says, “since I think that global human identity supersedes all other considerations.”

“We want to know who we are and where we came from,” Ostrer, who is now studying cancer risks among Ashkenazi Jews and Northern Israeli Druze populations, sums up. Even so, shared ancestry doesn’t necessarily imply a special bond. As Ostrer notes, citing the Biblical tale of Cain and Abel, “the fact that people are related to one another doesn’t prevent their developing extreme hostility to one another.”