Genetic studies of Jews
Genetic studies of Jews are part of the population genetics discipline and are used to analyze the ancestry of Jewish populations, complementing research in other fields such as history, linguistics, archaeology, paleontology, and medicine. These studies investigate the origins of various Jewish ethnic divisions by using DNA to investigate whether different Jewish and non-Jewish populations have shared ancestry or not. The medical genetics of Jews are studied for population-specific diseases and disease commonalities with other ethnicities.
Studies on Jewish populations have been principally conducted using three types of genealogical DNA tests: autosomal, mitochondrial, and Y-chromosome. Autosomal testing, which looks at the largest sets of genes within peoples' DNA, shows that Jewish populations tended to form genetic isolates – relatively closely related groups in independent communities with most in a community sharing significant ancestry. The Ashkenazi Jews form the largest such group. Mitochondrial and Y-DNA tests look at maternal and paternal ancestry respectively, via two small groups of genes transmitted only via female or male ancestors.
Studies on the genetic composition of Ashkenazi, Sephardi, and Mizrahi Jewish populations of the Jewish diaspora show significant amounts of shared Middle Eastern ancestry, as well as admixture from their host populations. Jews living in the North African, Italian, and Iberian regions show variable frequencies of genetic overlap with the historical non-Jewish population along the maternal lines. In the case of Ashkenazi and Sephardi Jews, who are closely related, the source of non-Middle-Eastern admixture is mainly Southern European. Some researchers have remarked on an especially close relationship between Ashkenazi Jews and modern Italians, Greeks, and other Southern Europeans. Bene Israel and the Cochin Jews of India, and Beta Israel of Ethiopia, resemble their local populations but also may have some near eastern lineages on the paternal side.
Religious, historical, and genetic perspectives on Jewish identity
and Jewish peoplehood are multifaceted, and there are multiple theories on the ethnic origins of Jews. In addition to the religion of Judaism, genetics and political and ethnic division have influenced Jewish identity. The traditional narrative is that Jews descended from the Israelites, without implying that all Jews are biological descendants, since conversion has always been part of Judaism. Attempts to furnish genetic evidence corroborating the biblical storytelling has been disputed.The advent of modern genetic research methods has led to extensive genetic studies on the topic. Such research has identified genotypic common denominators of Jewish people, but as per Raphael Falk, while certain detectable Middle Eastern genetic components exist in numerous Jewish communities, there is no evidence for a single Jewish prototype, and that "any general biological definition of Jews is meaningless".
Autosomal DNA
These studies focus upon autosomal chromosomes, the 22 homologous or autosomesSummary
Autosomal DNA studies show high levels of genetic relatedness among Ashkenazi, Sephardi, and Mizrahi Jews, corresponding to a shared Middle Eastern ancestry with variations in regional admixture. Autosomal DNA evidence supports the historical narrative of Jewish populations originating from the ancient Levant, with genetic diversity shaped by migrations, admixture, and isolation over millennia.Ashkenazi Jews share genetic similarities with Southern Europeans, such as Italians and Greeks, while exhibiting unique markers distinguishing them from non-Jewish groups. Similarly, North African Jews also exhibit proximity to European and Middle Eastern groups, reflecting their historical migration pattern. Other studies also reveal significant regional genetic diversity, such as the Berber admixture in Libyan Jews, or Ethiopian Jews' local ancestry combined with Middle Eastern links.
In autosomal analyses, the Iraqi Jews, Iranian Jews, Bukharian Jews, Kurdish Jews, Mountain Jews, and Georgian Jews form a close genetic cluster. When examined at a more detailed level, the groups can be separated from each other. This cluster plots between Levantine and Northern West Asian populations. Syrian and North African Jews are separate from it and closer to the Sephardi Jews. Yemenite Jews are distinct from other Jewish groups and cluster with the non-Jewish population of the Arabian Peninsula.
2017–present
In 2022, a three-year-long study that analyzed the DNA from the remains of 38 individuals from an excavated Jewish cemetery in Erfurt dating to the 14th century found that the medieval Erfurt Ashkenazi community was more genetically diverse than modern Ashkenazi Jews. The medieval Erfurt community was found to consist of two groups, one which had more Eastern European ancestry than modern Ashkenazi Jews and another with more Middle Eastern ancestry which was also genetically close to German and French Ashkenazi Jews and Turkish Sephardi Jews. The groups also had different levels of oxygen isotopes in their teeth, suggesting they used water sources from different areas in childhood, indicating that one of these groups migrated to Erfurt. These results seem to back up historical research which has suggested that medieval Ashkenazi Jewry was culturally divided between Western Jews, who originally lived in the Rhineland, and Eastern Jews, who originally lived in eastern Germany, Austria, Bohemia, Moravia, and Silesia. Erfurt lay at the boundary of these communities. The study also found evidence of the historic founder effect of Ashkenazi Jewry, with a third of the individuals sampled found to descend from a single woman along the maternal line. The genome of modern Ashkenazi Jewry was found to appear as a near-even mixture between the two groups, with about 60% of modern Ashkenazi DNA found to come from the group with more Middle Eastern ancestry and 40% found to come from the group with more Eastern European ancestry, suggesting that they eventually merged into a single Ashkenazi culture. The study's admixture models for Erfurt Ashkenazi Jews varied, but the authors concluded that "Under the extensive set of models we studied, the ME ancestry in EAJ is estimated in the range 19%–43% and the Mediterranean European ancestry in the range 37%–65% . However, the true ancestry proportions could be higher or lower than implied by these ranges." They continued, "Our results therefore should only be interpreted to suggest that AJ ancestral sources have links to populations living in Mediterranean Europe and the Middle East today."A 2020 genetic study on Bronze Age and Iron Age southern Levantine remains found evidence of large-scale migration of populations related to those of the Zagros or Caucasus into the southern Levant by the Bronze Age and increasing over time. The findings were found to be consistent with modern-day non-Jewish Arabic-speaking Levantine populations and Jewish groups, "having 50% or more of their ancestry from people related to groups who lived in the Bronze Age Levant and the Chalcolithic Zagros." Ashkenazi Jews were found to have 41% European admixture and Moroccan Jews were found to have 31% European admixture. Ethiopian Jews were found to derive 80% of their ancestry from an East African or Horn African component but also carried some Canaanite-like and Zagros-like ancestry. This does not necessarily mean that any these present-day groups bear direct ancestry from people who lived in the Middle to Late Bronze Age Levant or in Chalcolithic Zagros; rather, it indicates that they have ancestries from populations whose ancient proxy can be related to the Middle East.
A 2017 study by Xue et al., running different tests on Ashkenazi Jewish genomes found an approximately even mixture of Middle Eastern and European ancestry and concluded that the true fraction of European ancestry was possibly about 60% with the remaining 40% being Middle Eastern. The authors estimated the Levant as the most likely source of Middle Eastern ancestry in Ashkenazi Jews, and also estimated that between 60% and 80% of the European ancestry was Southern European, "with the rest being likely Eastern European."
2011–2016
In 2011, Moorjani et al. detected 3%–5% sub-Saharan African ancestry in all eight of the diverse Jewish populations that they analyzed. The timing of this African admixture among all Jewish populations was identical. The exact date was not determined, but it was estimated to have taken place between 1,600 and 3,400 years ago. Although African admixture was determined among South Europeans and Near Eastern populations too, this admixture was found to be younger compared to the Jewish populations. These findings the authors explained as evidence regarding the common origin of these 8 main Jewish groups. "It is intriguing that the Mizrahi Irani and Iraqi Jews—who are thought to descend at least in part from Jews who were exiled to Babylon about 2,600 years ago share the signal of African admixture. A parsimonious explanation for these observations is that they reflect a history in which many of the Jewish groups descend from a common ancestral population which was itself admixed with Africans, before the beginning of the Jewish diaspora that occurred in 8th to 6th century BC" the authors concluded.In 2012, two major genetic studies were carried out under the leadership of Harry Ostrer, from the Albert Einstein College of Medicine. The results were published in the Proceedings for the National Academy of Sciences. The genes of 509 Jewish donors from 15 different backgrounds and 114 non-Jewish donors of North African origin were analyzed. Ashkenazi, Sephardi, and Mizrahi Jews were found to be closer genetically to each other than to their long-term host populations, and all of them were found to have Middle Eastern ancestry, together with varying amounts of admixture in their local populations. Mizrahi and Ashkenazi Jews were found to have diverged from each other approximately 2,500 years in the past, approximately the time of the Babylonian exile. The studies also reconfirmed the results of previous studies which found that North African Jews were more closely related to each other and to European and Middle Eastern Jews than to their non-Jewish host populations. The genome-wide ancestry of North African Jewish groups was compared with respect to European, Maghrebi, and Middle Eastern origins. The Middle Eastern component was found to be comparable across all North African Jewish and non-Jewish groups, while North African Jewish groups showed increased European and decreased levels of North African ancestry with Moroccan and Algerian Jews tending to be genetically closer to Europeans than Djerban Jews. The study found that Yemenite, Ethiopian, and Georgian Jews formed their own distinctive, genetically linked clusters. In particular, Yemenite Jews, who had previously been believed to have lived in isolation, were found to have genetic connections to their host population, suggesting some conversion of local Arabs to Judaism had taken place. Georgian Jews were found to share close connections to Iraqi and Iranian Jews, as well as other Middle Eastern Jewish groups. The study also found that Syrian Jews share more genetic commonality with Ashkenazi Jews than with other Middle Eastern Jewish populations. According to the study:
distinctive North African Jewish population clusters with proximity to other Jewish populations and variable degrees of Middle Eastern, European, and North African admixture. Two major subgroups were identified by principal component, neighbor joining tree, and identity-by-descent analysis—Moroccan/Algerian and Djerban/Libyan—that varied in their degree of European admixture. These populations showed a high degree of endogamy and were part of a larger Ashkenazi and Sephardic Jewish group. By principal component analysis, these North African groups were orthogonal to contemporary populations from North and South Morocco, Western Sahara, Tunisia, Libya, and Egypt. Thus, this study is compatible with the history of North African Jews—founding during Classical Antiquity with proselytism of local populations, followed by genetic isolation with the rise of Christianity and then Islam, and admixture following the emigration of Sephardic Jews during the Inquisition.
Ostrer also found that Ethiopian Jews are predominantly related to the indigenous populations of Ethiopia, but do have distant genetic links to the Middle East from more than 2,000 years in the past, and are likely descended from a few Jewish founders. It was speculated that the community began when a few itinerant Jews settled in Ethiopia in ancient times, converted locals to Judaism, and married into the local populations.
A 2012 study by Eran Elhaik analyzed data collected for previous studies and concluded that the DNA of Eastern and Central European Jewish populations indicates that their ancestry is "a mosaic of Caucasus, European, and Semitic ancestries". For the study, Bedouins and Jordanian Hashemites, known to descend from Arabian tribes, were assumed to be a valid genetic surrogate of ancient Jews, whereas the Druze, known to come from Syria, were assumed to be non-Semitic immigrants into the Levant. Armenians and Georgians were also used as surrogate populations for the Khazars, who spoke a Turkic language unrelated to Georgian or Armenian. On this basis, a relatively strong connection to the Caucasus was proposed because of the stronger genetic similarity of these Jewish groups to modern Armenians, Georgians, Azerbaijani Jews, Druze and Cypriots, compared to a weaker genetic similarity with Hashemites and Bedouins. This proposed Caucasian component of ancestry was in turn taken to be consistent with the Khazarian Hypothesis as an explanation of part of the ancestry of Ashkenazi Jews.
A study by Haber et al. noted that while previous studies of the Levant, which had focused mainly on diaspora Jewish populations, showed that the "Jews form a distinctive cluster in the Middle East", these studies did not make clear "whether the factors driving this structure would also involve other groups in the Levant". The authors found strong evidence that modern Levant populations descend from two major apparent ancestral populations. One set of genetic characteristics that are shared with modern-day Europeans and Central Asians is most prominent in the Levant amongst "Lebanese, Armenians, Cypriots, Druze and Jews, as well as Turks, Iranians, and Caucasian populations". The second set of inherited genetic characteristics is shared with populations in other parts of the Middle East as well as some African populations. Levant populations in this category today include "Palestinians, Jordanians, Syrians, as well as North Africans, Ethiopians, Saudis, and Bedouins". Concerning this second component of ancestry, the authors remark that while it correlates with "the pattern of the Islamic expansion", and that "a pre-Islamic expansion Levant was more genetically similar to Europeans than to Middle Easterners," they also say that "its presence in Lebanese Christians, Sephardi and Ashkenazi Jews, Cypriots, and Armenians might suggest that its spread to the Levant could also represent an earlier event". The authors also found a strong correlation between religion and apparent ancestry in the Levant:
all Jews cluster in one branch; Druze from Mount Lebanon and Druze from Mount Carmel are depicted on a private branch; and Lebanese Christians form a private branch with the Christian populations of Armenia and Cyprus placing the Lebanese Muslims as an outer group. The predominantly Muslim populations of Syrians, Palestinians, and Jordanians cluster on branches with other Muslim populations as distant as Morocco and Yemen.
A 2013 study by Doron M. Behar, Mait Metspalu, Yael Baran, Naama M. Kopelman, Bayazit Yunusbayev et al. using integration of genotypes on newly collected largest data set available to date for assessment of Ashkenazi Jewish genetic origins from the regions of potential Ashkenazi ancestry: concluded that "This most comprehensive study... does not change and in fact reinforces the conclusions of multiple past studies, including ours and those of other groups. We confirm the notion that the Ashkenazi, North African, and Sephardi Jews share substantial genetic ancestry and that they derive it from Middle Eastern and European populations, with no indication of a detectable Khazar contribution to their genetic origins."
The authors also reanalyzed the 2012 study of Eran Elhaik and found that "The provocative assumption that Armenians and Georgians could serve as appropriate proxies for Khazar descendants is problematic for a number of reasons as the evidence for ancestry among Caucasus populations do not reflect Khazar ancestry". Also, the authors found that "Even if it were allowed that Caucasus affinities could represent Khazar ancestry, the use of the Armenians and Georgians as Khazar proxies is particularly poor, as they represent the southern part of the Caucasus region, while the Khazar Khaganate was centered in the North Caucasus and further to the north. Furthermore, among populations of the Caucasus, Armenians and Georgians are geographically the closest to the Middle East, and are therefore expected a priori to show the greatest genetic similarity to Middle Eastern populations." Concerning the similarity of South Caucasus populations to Middle Eastern groups which was observed at the level of the whole genome in one recent study. The authors found that "Any genetic similarity between Ashkenazi Jews and Armenians and Georgians might merely reflect a common shared Middle Eastern ancestry component, actually providing further support to a Middle Eastern origin of Ashkenazi Jews, rather than a hint for a Khazar origin". The authors claimed "If one accepts the premise that similarity to Armenians and Georgians represents Khazar ancestry for Ashkenazi Jews, then by extension one must also claim that Middle Eastern Jews and many Mediterranean European and Middle Eastern populations are also Khazar descendants. This claim is clearly not valid, as the differences among the various Jewish and non-Jewish populations of Mediterranean Europe and the Middle East predate the period of the Khazars by thousands of years".
A 2014 scientific study by geneticists, Shai Carmi, PhD et al. published by Nature Communications found that the Ashkenazi Jewish population originates from an even mixture between Middle Eastern and European peoples, descending from 330 to 350 individuals who were genetically about half-Middle Eastern and half-European, making all Ashkenazi Jews related to the point of being at least 30th cousins or closer. According to the authors, this genetic bottleneck likely occurred some 600–800 years in the past, followed by rapid growth and genetic isolation. The principal component analysis of common variants in the sequenced AJ samples confirmed previous observations, namely, the proximity of the Ashkenazi Jewish cluster to other Jewish, European, and Middle Eastern populations. This was confirmed by another 2022 genome study by Shamam Waldman PhD et al. published by Cell that modern Ashkenazi Jews descend from a small group, with the original researcher, Shai Carmi, stating, "Whether they're from Israel or New York, the Ashkenazi population today is homogenous genetically."
A 2016 study by Elhaik et al. in the Oxford University Press published journal Genome Biology and Evolution found that the DNA of Ashkenazi Jews originated in northeastern Turkey. The study found 90% of Ashkenazi Jews could be traced to four ancient villages in northeastern Turkey. The researchers speculated that the Ashkenazi Jews originated in the first millennium, when Iranian Jews converted Greco-Roman, Turkish, Iranian, southern Caucasian, and Slavic populations inhabiting Turkey, and speculated that the Yiddish language also originated there among Jewish merchants as a cryptic language in order to gain advantage in trade along the Silk Road.
In a joint study published in 2016 by Genome Biology and Evolution, a group of geneticists and linguists from the UK, Czech Republic, Russia, and Lithuania, dismissed both the genetic and linguistic components of Elhaik's 2016 study. As for the genetic component, the authors argued that using a genetic "GPS tool" would place Italians and Spaniards into Greece, all Tunisians and some Kuwaitis would be placed in the Mediterranean Sea, all Greeks were positioned in Bulgaria and in the Black Sea, and all Lebanese were scattered along a line connecting Egypt and the Caucasus; "These cases are sufficient to illustrate that mapping of test individuals has nothing to do with ancestral locations" the authors wrote. As for the linguistic component, the authors stated "Yiddish is a Germanic language, leaving no room for the Slavic relexification hypothesis and for the idea of early Yiddish-Persian contacts in Asia Minor. The study concluded that 'Yiddish is a Slavic language created by Irano-Turko-Slavic Jewish merchants along the Silk Roads as a cryptic trade language, spoken only by its originators to gain an advantage in trade' remains an assertion in the realm of unsupported speculation", the study concluded.
In an ancient DNA analysis by Elhaik of six Natufians and a Levantine Neolithic, some of the likely Judaean progenitors, the ancient individuals clustered predominantly with modern-day Palestinians and Bedouins and marginally overlapped with Arabian Jews. Ashkenazic Jews clustered away from these ancient Levantine individuals and adjacent to Neolithic Anatolians and Late Neolithic and Bronze Age Europeans.
A 2016 study of Indian Jews from the Bene Israel community by Waldman et al. found that the genetic composition of the community is "unique among Indian and Pakistani populations we analyzed in sharing considerable genetic ancestry with other Jewish populations. Putting together the results from all analyses point to Bene Israel being an admixed population with both Jewish and Indian ancestry, with the genetic contribution of each of these ancestral populations being substantial." The authors also examined the proportion and roots of the shared Jewish ancestry and the local genetic admixture: "In addition, we performed f4-based analysis to test whether Bene Israel are closer to Jews than to non-Jewish Middle-Eastern populations. We found that Middle-Eastern Jewish populations were closer to Bene Israel as compared to other Middle-Eastern populations examined. Non-Middle-Eastern Jewish populations were still closer to Bene Israel as compared to Bedouin and Palestinians, but not as compared to Druze. These results further support the hypothesis that the non-Indian ancestry of Bene Israel is Jewish specific, likely from a Middle-Eastern Jewish population."