Genetic studies of Jews

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 autosomes (non-sex chromosomes) Summary 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. Ashkenazi Jews share genetic similarities with Southern Europeans, such as Italians and Greeks, while exhibiting unique markers distinguishing them from non-Jewish groups. 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. 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 who may be the group with more Middle Eastern ancestry), and Eastern Jews, who originally lived in eastern Germany, Austria, Bohemia, Moravia, and Silesia (and who may be the group with more European ancestry). 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 (EAJ) varied, but the authors concluded that "Under the extensive set of models we studied, the ME [Middle Eastern] ancestry in EAJ is estimated in the range 19%–43% and the Mediterranean European ancestry in the range 37%–65% [the remainder of the European ancestry being Eastern European]. 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 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 (Ashkenazi Jews, Syrian Jews, Iranian Jews, Iraqi Jews, Greek Jews, Turkish Jews, Italian Jews) that they analyzed. The timing of this African admixture among all Jewish populations was identical but not determined. 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. 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 were found to have Middle Eastern ancestry, 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 (Basque), Maghrebi (Tunisian non-Jewish), and Middle Eastern (Palestinian) 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 (Maghrebi) ancestry with Moroccan and Algerian Jews tending to be genetically closer to Europeans than Djebar Jews. The study found that Syrian Jews share more genetic commonality with Ashkenazi Jews than with other Middle Eastern Jewish populations. 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. Possibly the community began when itinerant Jews settled in Ethiopia in ancient times, and married local women who converted to Judaism. 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. 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. A study by Haber et al. (2013) 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 also found a strong correlation between religion and apparent ancestry in the Levant: all Jews (Sephardi and Ashkenazi) 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 a newly collected largest data set available to date (1,774 samples from 106 Jewish and non-Jewish populations) 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 (Atzmon and others, 2010; Bauchet and others, 2007; Behar and others, 2010; Campbell and others, 2012; Guha and others, 2012; Haber and others; 2013; Henn and others, 2012; Kopelman and others, 2009; Seldin and others, 2006; Tian and others, 2008). 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 (Yunusbayev and others, 2012), 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 (Hebrew University) 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 (rate per generation 16–53%). 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. A 2016 study by Elhaik et al. 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. Elhaik's findings were promptly refuted by a joint study published in 2016 by a group of geneticists and linguists from the UK, Czech Republic, Russia, and Lithuania; they dismissed both the genetic and linguistic components of Elhaik's article. As for the genetic component, the authors argued that using a genetic "GPS tool" (as used by Elhaik et al.) 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' (Das et al. 2016) remains an assertion in the realm of unsupported speculation", the study concluded. 2001–2010 An autosomal DNA study carried out in 2010 by Atzmon et al. examined the origin of Iranian, Iraqi, Syrian, Turkish, Greek, Sephardic, and Ashkenazi Jewish communities. The study compared these Jewish groups with 1043 unrelated individuals from 52 worldwide populations. To further examine the relationship between Jewish communities and European populations, 2407 European subjects were assigned and divided into 10 groups based on the geographic region of their origin. This study confirmed previous findings of shared Middle Eastern origin of the above Jewish groups and found that "the genetic connections between the Jewish populations became evident from the frequent identity by descent (IBD) across these Jewish groups (63% of all shared segments). Jewish populations shared more and longer segments with one another than with non-Jewish populations, highlighting the commonality of Jewish origin. Among pairs of populations ordered by total sharing, 12 out of the top 20 were pairs of Jewish populations, and "none of the top 30 paired a Jewish population with a non-Jewish one". Atzmon concludes that "Each Jewish group demonstrated Middle Eastern ancestry and variable admixture from host population, while the split between Middle Eastern and European/Syrian Jews, calculated by simulation and comparison of length distributions of IBD segments, occurred 100–150 generations ago, which was described as "compatible with a historical divide that is reported to have occurred more than 2500 years ago" as the Jewish community in Iraq and Iran were formed by Jews in the Babylonian and Persian empires during and after Babylonian exile. The main difference between Mizrahi and Ashkenazi/Sephardic Jews was the absence of Southern European components in the former. According to these results, European/Syrian Jewish populations, including the Ashkenazi Jewish community, were formed later, as a result of the expulsion and migration of Jews from Palestine, during Roman rule. Concerning Ashkenazi Jews, this study found that genetic dates "are incompatible with theories that Ashkenazi Jews are for the most part the direct lineal descendants of converted Khazars or Slavs". Citing Behar, Atzmon states that "Evidence for founder females of Middle Eastern origin has been observed in all Jewish populations based on non-overlapping mitochondrial haplotypes with coalescence times >2000 years". The closest people related to Jewish groups were the Palestinians, Bedouins, Druze, Greeks, and Italians. Regarding this relationship, the authors conclude that "These observations are supported by the significant overlap of Y chromosomal haplogroups between Israeli and Palestinian Arabs with Ashkenazi and non-Ashkenazi Jewish populations". A 2010 study by Zoossmann-Diskin concluded that based upon the analysis of the X chromosome and seventeen autosomal markers, Eastern European Jewish populations and Jewish populations from Iran, Iraq, and Yemen, do not have the same genetic origins. In particular, concerning Eastern European Jews, he concluded that the evidence points to a dominant amount of southern European, and specifically Italian, ancestry, which he attributed to the conversions to Judaism in ancient Rome which are also supported by historical evidence. Concerning the similarity between Sephardi and Ashkenazi Jews, he stated that the reasons are uncertain but that it is likely to be caused by Sephardic Jews having "Mediterranean basin" ancestry also like the Ashkenazi Jews. A 2009 study on various European and Near Eastern ethnic groups found Ashkenazi Jews to show closer Genetic distance (Fst) with Italians, Greeks, Germans, and other European groups than what they show with Levantine groups such as Druze and Palestinians. Though it also found that the Ashkenazi Jews were mainly a population "clearly of southern" [Mediterranean] origin", they "appear to have a unique genotypic pattern that may not reflect geographic origins." A 2009 study by Goldstein et al. shows that it is possible to predict full Ashkenazi Jewish ancestry with 100% sensitivity and 100% specificity, although the exact dividing line between a Jewish and non-Jewish cluster will vary across sample sets which in practice would reduce the accuracy of the prediction. While the full historical demographic explanations for this distinction remain to be resolved, it is clear that the genomes of individuals with full Ashkenazi Jewish ancestry carry an unambiguous signature of their Jewish ancestral DNA, the author suggested that it is more likely to be due to their specific Middle Eastern ancestry than to inbreeding. The authors note that there is almost perfect separation along PC 1, and, they note that most of the non-Jewish Europeans who are closest to the Jews on this PC are of Italian or Eastern Mediterranean origin. Another study by L. Hao et al. A 2008 study by Tian et al. provides an additional example of the same clustering pattern, using samples and markers similar to those in their other study. European population genetic substructure was examined in a diverse set of >1,000 individuals of European descent, each genotyped with >300 K SNPs. Both STRUCTURE and principal component analyses (PCA) showed the largest division/principal component (PC) differentiated northern from southern European ancestry. A second PC further separated Italian, Spanish, and Greek individuals from those of Ashkenazi Jewish ancestry as well as distinguishing among northern European populations. In separate analyses of northern European participants other substructure relationships were discerned showing a west-to-east gradient. In June 2010, Behar et al. "shows that most Jewish samples form a remarkably tight subcluster with common genetic origin, that overlies Druze and Cypriot samples but not samples from other Levantine populations or paired Diaspora host populations. In contrast, Ethiopian Jews (Beta Israel) and Indian Jews (Bene Israel and Cochini) cluster with neighboring autochthonous populations in Ethiopia and western India, respectively, despite a clear paternal link between the Bene Israel and the Levant." "The most parsimonious explanation for these observations is a common genetic origin, which is consistent with an historical formulation of the Jewish people as descending from ancient Hebrew and Israelite residents of the Levant." In July 2010, Bray et al., using SNP microarray techniques and linkage analysis, found that Ashkenazi Jews clustered between Middle Eastern and European populations but found a closer relationship between the Ashkenazim and several European populations (Tuscans, Italians, and French) than between the Ashkenazi Jews and Middle Eastern populations and that European admixture "is considerably higher than previous estimates by studies that used the Y chromosome." They add their study data "support the model of a Middle Eastern origin of the Ashkenazim population followed by subsequent admixture with host Europeans or populations more similar to Europeans," and that their data imply that modern Ashkenazi Jews are possibly more similar to Europeans than modern Middle Easterners. The level of admixture with European populations was estimated at between 35% and 55%. The study assumed Druze and Palestinian Arab populations to represent the reference to the world Jewry ancestor genome. With this reference point, the linkage disequilibrium in the Ashkenazi Jewish population was interpreted as "matches signs of interbreeding or 'admixture' between Middle Eastern and European populations". Also, in their press release, Bray stated: "We were surprised to find evidence that Ashkenazi Jews have higher heterozygosity than Europeans, contradicting the widely-held presumption that they have been a largely isolated group". The authors said that their calculations might have "overestimated the level of admixture" as it is possible that the true Jewish ancestors were genetically closer to Southern Europeans than to Druze and Palestinian Arabs. They predicted that using the non-Ashkenazi Jewish Diaspora populations as a reference for a world Jewry ancestor genome would "underestimate the level of admixture" but that "however, using the Jewish Diaspora populations as the reference Jewish ancestor will naturally underestimate the true level of admixture, as the modern Jewish Diaspora has also undergone admixture since their dispersion. A 2006 study by Seldin et al. used over five thousand autosomal SNPs to demonstrate the European genetic substructure. The results showed "a consistent and reproducible distinction between 'northern' and 'southern' European population groups". Most northern, central, and eastern Europeans (Finns, Swedes, English, Irish, Germans, and Ukrainians) showed >90% in the 'northern' population group, while most individual participants with southern European ancestry (Italians, Greeks, Portuguese, Spaniards) showed >85% in the 'southern' group. Both Ashkenazi Jews as well as Sephardic Jews showed >85% membership in the "southern" group. Referring to the Jews clustering with southern Europeans, the authors state the results were "consistent with a later Mediterranean origin of these ethnic groups". An initial study conducted in 2001 by Noah Rosenberg and colleagues on six Jewish populations (Poland, Libya, Ethiopia, Iraq, Morocco, Yemen) and two non-Jewish populations (Palestinians and Druze) showed that while the eight groups had genetic links to each other, the Jews of Libya have a distinct genetic signature related to their genetic isolation and possible admixture with Berber populations. This same study suggested a close relationship between the Jews of Yemen and those of Ethiopia. == Paternal line ==

distribution map Summary Approximately 35% to 43% of Jewish men are in the paternal line known as haplogroup J and its sub-haplogroups. This haplogroup is particularly present in the Middle East and Southern Europe. 15% to 30% are in haplogroup E1b1b, (or E-M35) and its sub-haplogroups which is common in the Middle East, North Africa, and Southern Europe. The Mediterranean haplogroup T1a1 is found in varying percentages depending on the Jewish group studied but with upward of 15 to 3% with the highest frequency within Jewish communities native to the Fertile Crescent and East Africa. distribution map Studies of Levites and Cohanim provide further insights into Jewish paternal heritage. The Cohanim lineage, traditionally associated with priestly descent, has been linked to the Cohen Modal Haplotype (CMH), first identified by Skorecki et al. in 1997. These genetic findings, together with broader studies of Y-DNA haplogroups frequencies, suggest a shared Middle Eastern origin across Jewish populations, shaped by migrations, isolation, and limited admixture with host populations. Y-DNA Studies on Jewish Lineages In 1992, G. Lucotte and F. David were the first genetic researchers to have documented a common paternal genetic heritage between Sephardi and Ashkenazi Jews. Another study published just a year later suggested the Middle Eastern origin of Jewish paternal lineages. In 2000, M. Hammer, et al. conducted a study on 1,371 men and definitively established that part of the paternal gene pool of Jewish communities in Europe, North Africa, and the Middle East came from a common Middle East ancestral population. They suggested that most Jewish communities in the Diaspora remained relatively isolated and endogamous compared to non-Jewish neighbor populations. Kurdish, North African Sephardi, and Iraqi Jews were found to be genetically indistinguishable while slightly but significantly differing from Ashkenazi Jews. In relation to the region of the Fertile Crescent, the same study noted; "In comparison with data available from other relevant populations in the region, Jews were found to be more closely related to groups in the north of the Fertile Crescent (Kurds, Turks, and Armenians) than to their Arab neighbors", which the authors suggested was due to migration and admixture from the Arabian Peninsula into certain current Arabic-speaking populations during the period of Islamic expansion. That is, the commonness of nominally Middle Eastern subclades of R1b amongst Ashkenazim tends to minimize the Western European contribution to the ~10% of R1b found amongst Ashkenazim. A large study by Behar et al. (2004) of Ashkenazi Jews records a percentage of 5–8% European contribution to the Ashkenazi paternal gene pool. In the words of Behar: For G. Lucotte et al., the R1b frequency is about 11%. In 2004, when the calculation was made excluding Jews from the Netherlands the R1b rate was 5% ± 11.6%. This hypothesis is also supported by David B. Goldstein in his book ''Jacob's legacy: A genetic view of Jewish history''. However, Faerman (2008) states that "External low-level gene flow of possible Eastern European origin has been shown in Ashkenazim but no evidence of a hypothetical Khazars' contribution to the Ashkenazi gene pool has ever been found." A 2017 study, concentrating on the Ashkenazi Levites where the proportion reaches 50%, while signaling that there's a "rich variation of haplogroup R1a outside of Europe which is phylogenetically separate from the typically European R1a branches", notes that the particular R1a-Y2619 sub-clade testifies for a local origin, and that the "Middle Eastern origin of the Ashkenazi Levite lineage based on what was previously a relatively limited number of reported samples, can now be considered firmly validated." Furthermore, 7% of Ashkenazi Jews have the haplogroup G2c, which is mainly found among the Pashtuns and on a lower scale, it is mainly found among members of all major Jewish ethnic groups, Palestinians, Syrians, and Lebanese. Behar et al. suggest that those haplogroups are minor Ashkenazi founding lineages. the second of F. Manni et al. of 2005. They also conclude that the Jews of Djerba's paternal gene pool is different from the Arabs and Berbers of the island. For the first 77.5% of samples tested are of haplotype VIII (probably similar to the J haplogroup according Lucotte), the second shows that 100% of the samples are of Haplogroup J *. The second suggests that it is unlikely that the majority of this community comes from an ancient colonization of the island while for Lucotte it is unclear whether this high frequency is really an ancient relationship. These studies therefore suggest that the paternal lineage of North African Jews comes predominantly from the Middle East with a minority contribution of African lineages, probably Berbers. A study by Inês Nogueiro et al. (July 2009) on the Jews of north-eastern Portugal (region of Trás-os-Montes) showed that their paternal lines consisted of 35.2% lineages more typical of Europe (R : 31.7%, I : 3.5%), and 64.8% lineages more typical of the Near East than Europe (E1b1b: 8.7%, G: 3.5%, J: 36.8%, T: 15.8%) and consequently, the Portuguese Jews of this region were genetically closer to other Jewish populations than to Portuguese non-Jews. Y-DNA of Mizrahi Jews In the article by Nebel et al. A 2002 study by geneticist Dror Rosengarten found that the paternal haplotypes of Mountain Jews "were shared with other Jewish communities and were consistent with a Mediterranean origin." A 2016 study by Karafet at all found, with a sample of 17, 11.8% of Mountain Jewish men tested in Dagestan's Derbentsky District to belong to Haplogroup T-P77. The studies of Shen Hammer et al. (2000) Priestly families Cohanim Nephrologist Karl Skorecki decided to analyze the Cohanim to see if they were the descendants of one man, in which case they should have a set of common genetic markers. To test this hypothesis, he contacted Michael Hammer of the University of Arizona, a researcher in molecular genetics and a pioneer in research on chromosomes. Their article, published in Nature in 1997, has had some impact. A set of special markers (called Cohen Modal Haplotype or CMH) was defined as one which is more likely to be present in the Cohanim, defined as contemporary Jews named Cohen or a derivative, and it was proposed that this results from a common descent from the ancient priestly lineage rather than from the Jewish population in general. But, subsequent studies showed that the number of genetic markers used and the number of samples (of people saying Cohen) were not big enough. The last study, conducted in 2009 by Hammer and Behar et al., Levites A 2003 study of the Y-chromosome by Behar et al. pointed to multiple origins for Ashkenazi Levites, a priestly class who comprise approximately 4% of Ashkenazi Jews. It found that Haplogroup R1a1a (R-M17), which is uncommon in the Middle East or among Sephardi Jews, but dominant in Eastern Europe, is present in over 50% of Ashkenazi Levites, while the rest of Ashkenazi Levites' paternal lineage is of apparent Middle Eastern origin. Behar suggested a founding event, probably involving one or very few European men, occurring at a time close to the initial formation and settlement of the Ashkenazi community as a possible explanation. Nebel, Behar and Goldstein speculated that this may indicate a Khazar origin. However, a 2013 study by Rootsi, Behar et al. found that R1a-M582, the specific subclade of R1a to which all sampled Ashkenazi Levites with R1a belonged, was completely absent from a sample of 922 Eastern Europeans and was only found in one of the 2,164 samples from the Caucasus, while it made up 33.8% of non-Levite Ashkenazi R1a and was also found in 5.9% of Near Easterners bearing R1a. The clade, though less represented in Near Easterners, was more diverse among them than among Ashkenazi Jews. Rootsi et al. argued this supports a Near Eastern Hebrew origin for the paternal lineage R1a present among Ashkenazi Levites: R1a-M582 was also found among different Iranian populations, among Kurds from Cilician Anatolia and Kazakhstan, and among non-Ashkenazi Jews. == Maternal line ==

Summary Studies of mitochondrial DNA of Jewish populations are more recent and are still debatable. Scholars such as Harry Ostrer and Raphael Falk believe this may indicate that many Jewish males found new mates from European and other communities in the places where they migrated in the diaspora after fleeing ancient Israel. although later research suggests that up to 81% of their maternal ancestry might stem from European women. Some studies propose ancient Near Eastern origins, These patterns suggest distinct genetic clusters for Ashkenazi, Sephardi, and Mizrahi Jews. Two studies in 2006 and 2008 suggested that about 40% of Ashkenazi Jews originate maternally from four female founders likely of Near-Eastern origin who lived 1,000 years ago, while the populations of Sephardi and Mizrahi Jewish communities "showed no evidence for a narrow founder effect". In 2013, however, Richards et al. published work suggesting that an overwhelming majority of Ashkenazi Jewish maternal ancestry, estimated at "80 percent of Ashkenazi maternal ancestry comes from women indigenous to Europe, and [only] 8 percent from the Near East, with the rest uncertain", suggesting that Jewish males migrated to Europe and took new wives from the local population, and converted them to Judaism, though some geneticists, such as Doron Behar, have expressed disagreement with the study's conclusions. Reflecting on previous mtDNA studies carried out by Behar, Atzmon et al. conclude that all major Jewish population groups are showing evidence for founder females of Middle Eastern origin with coalescence times >2000 years. Haplogroup K itself is thought to have originated in Western Asia some 12,000 years ago. A 2006 study by Behar et al., confirmed the hypothesis of the founding of non-European origin among the maternal lines. Their study did not address the geographical origin of Ashkenazim and therefore does not explicitly confirm the origin "Levantine" of these founders. This study revealed a significant divergence in total haplogroup distribution between the Ashkenazi Jewish populations and their European host populations, namely Russians, Poles, and Germans. They concluded that, regarding mtDNAs, the differences between Jews and non-Jews are far larger than those observed among the Jewish communities. The study also found that "the differences between the Jewish communities can be overlooked when non-Jews are included in the comparisons." It supported previous interpretations that, in the direct maternal line, there was "little or no gene flow from the local non-Jewish communities in Poland and Russia to the Jewish communities in these countries." They wrote: If we allow for the possibility that K1a9 and N1b2 might have a Near Eastern source, then we can estimate the overall fraction of European maternal ancestry at ~65%. Given the strength of the case for even these founders having a European source, however, our best estimate is to assign ~81% of Ashkenazi lineages to a European source, ~8% to the Near East, and ~1% further to the east in Asia, with ~10% remaining ambiguous... Thus at least two-thirds and most likely more than four-fifths of Ashkenazi maternal lineages have a European ancestry. David B. Goldstein, the Duke University geneticist who first found similarities between the founding mothers of Ashkenazi Jewry and European populations, said that, although Richards' analysis was well-done and 'could be right,' A critique of the study by Livni and Skorecki was published in a subsequent issue of the same journal, suggesting higher European maternal input, although less than Costa et al. had suggested, and stressing the importance of studying ancient DNA. MtDNA of Sephardi Jews Analysis of mitochondrial DNA of the Jewish populations of North Africa (Morocco, Tunisia, Libya) was the subject of further detailed study in 2008 by Doron Behar et al. Their text concludes that Jews from this region do not share the haplogroups of the mitochondrial DNA haplogroups (M1 and U6) that are typical of the North African Berber and Arab populations. Behar et al. conclude that it is unlikely that North African Jews have significant Arab, or Berber admixture, "consistent with social restrictions imposed by religious restrictions," or endogamy. This study also found genetic similarities between the Ashkenazi and North African Jews of European mitochondrial DNA pools, but differences between both of these of the diaspora and Jews from the Middle East. This finding suggests that the sub-haplogroup, which resembles the populations who live between Saudi Arabia, Egypt and North Central Italy more than the local Iberians, occurred relatively early in the Sephardic population because if it appeared instead at the end of the community's isolation in Iberia, there would be insufficient time for its spread in the population. The frequency of T2e matches in Spain and Portugal is drastically lower than in those listed above Jews. Similarly, fewer Sephardic signature T2e5 matches were found in Iberia than in Northern Mexico and Southwest United States. Behar et al. proposed that the existence of the mtDNA haplogroup HV0 among Jews from Turkey might represent the "genetic signal of an admixture of Iberian Jewry with local Iberian populations". The Mountain Jews showed a striking maternal founding event, with 58.6% of their total mtDNA genetic variation tracing back to one woman from the Levant carrying an mtDNA lineage within Hg J2b. These sub-Saharan haplogroups are virtually absent among Jews from Iraq, Iran, and Georgia and do not appear among Ashkenazi Jews. == Comparison to non-Jewish populations ==

Levantines of world populations showing various Jewish and non-Jewish groups Many genetic studies have demonstrated that most of the various Jewish ethnic divisions, Palestinians, Recent research published in the South African Medical Journal studied Y-Chromosome variations in two groups of Lemba, one South African and the other Zimbabwean (the Remba). It concluded that "While it was not possible to trace unequivocally the origins of the non-African Y chromosomes in the Lemba and Remba, this study does not support the earlier claims of their Jewish genetic heritage." The researcher suggested "a stronger link with Middle Eastern populations, probably the result of trade activity in the Indian Ocean." Inhabitants of Spain, Portugal, and Ibero-America According to a 2008 study by Adams and colleagues the inhabitants of the Iberian Peninsula (Spain and Portugal) have an average of 20% Sephardi Jewish ancestry, with significant geographical variations ranging from 0% on Menorca to 36.3% in southern Portugal. According to the authors, part of this admixture might also be of Neolithic, Phoenician, or Arab-Syrian origin. Researchers analyzed "two well-established communities in Colorado (33 unrelated individuals) and Ecuador (20 unrelated individuals) with a measurable prevalence of the BRCA1 c.185delAG and the GHR c.E180 mutations, respectively [...] thought to have been brought to these communities by Sephardic Jewish progenitors. [...] When examining the presumed European component of these two communities, we demonstrate enrichment for Sephardic Jewish ancestry not only for these mutations but also for other segments as well. [...] These findings are consistent with historical accounts of Jewish migration from the realms that comprise modern Spain and Portugal during the Age of Discovery. More importantly, they provide a rationale for the occurrence of mutations typically associated with the Jewish diaspora in Latin American communities." == Studies on historical populations ==

A 2020 study on remains from Bronze Age southern Levantine (Canaanite) populations found evidence of large-scale migration from the Zagros or Caucasus into the southern Levant by the Bronze Age and increasing over time (resulting in a Canaanite population descended from both those migrants and earlier Neolithic Levantine peoples). The results were found to be consistent with several Jewish groups (Moroccan, Ashkenazi, and Persian/Iranian Jews) and non-Jewish Arabic-speaking Levantine populations (such as Lebanese, Druze, Palestinians, and Syrians) deriving about half or more of their ancestry from populations related to those from the Bronze Age Levant and Chalcolithic Zagros. The study modeled the aforementioned groups as having ancestry from both ancient populations. In a study published in December 2022, new genome data obtained from the medieval Jewish cemetery of Erfurt, Germany was used to further trace the origins of the Ashkenazi Jewish community. These findings suggest that medieval Erfurt had at least two related but genetically distinct Jewish groups: one was closely related to Middle Eastern populations and was especially similar to modern Ashkenazi Jews from France and Germany and modern Sephardic Jews from Turkey; the other group had a substantial contribution from Eastern European populations. Modern Ashkenazi Jews from Eastern Europe no longer exhibit this genetic variability, and instead, their genomes resemble a nearly even mixture of the two Erfurt groups (with about 60% from the first group and 40% from the second). A study of Catalonian Jews published in Genes in March 2026 analyzed victims of the 1348 pogrom against Jews in Tàrrega, Spain, whose bodies were deposited in a mass grave in the town's Roquetes necropolis, and found numerous paternal and maternal haplogroups in common with modern Ashkenazi Jews and Sephardic Jews as well as Jewish patterns in their autosomal DNA. ==Hypotheses==

. A 2009 study was able to genetically identify individuals with full or partial Ashkenazi Jewish ancestry. In August 2012, Legacy: A Genetic History of the Jewish People, a book by Harry Ostrer, concluded that all major Jewish groups share a common Middle Eastern origin. Ostrer also refuted the Khazar hypothesis of Ashkenazi ancestry. Autosomal genetic analysis in 2012 revealed that North African Jews are genetically close to European Jews, which "shows that North African Jews date to biblical-era Israel, and are not largely the descendants of natives who converted to Judaism." A study conducted in 2013 by Behar et al. found no evidence of a Khazar origin for Ashkenazi Jews and stated that this lack of evidence "corroborates earlier results that Ashkenazi Jews derive their ancestry primarily from populations of the Middle East and Europe, that they possess considerable shared ancestry with other Jewish populations, and that there is no indication of a significant genetic contribution either from within or from north of the Caucasus region." In 2016, Eran Elhaik, together with Ranajit Das, Paul Wexler and Mehdi Pirooznia, advanced the view that the first Ashkenazi populations to speak Yiddish came from areas near four villages in Eastern Anatolia along the Silk Road whose names derived from the word "Ashkenaz", arguing that Iranian, Greek, Turkish, and Slav populations converted on that travel route before moving to Khazaria, where a small-scale conversion took place. The study was widely dismissed by genomics researchers as well as linguists. In a joint study published in 2016 by Genome Biology and Evolution, Pavel Flegontov from Department of Biology and Ecology, Faculty of Science, University of Ostrava, Czech Republic, A. A. Kharkevich Institute of Linguistics, Russian Academy of Sciences, Moscow, Mark G. Thomas from Research Department of Genetics, Evolution and Environment, University College London, UK, Valentina Fedchenko from Saint Petersburg State University, and George Starostin from Russian State University for the Humanities, dismissed both the genetic and linguistic components of Elhaik et al. study arguing that "GPS is a provenancing tool suited to inferring the geographic region where a modern and recently unadmixed genome is most likely to arise, but is hardly suitable for admixed populations and for tracing ancestry up to 1000 years before present, as its authors have previously claimed. Moreover, all methods of historical linguistics concur that Yiddish is a Germanic language, with no reliable evidence for Slavic, Iranian, or Turkic substrata." The authors concluded:"In our view, Das and co-authors have attempted to fit together a marginal and unsupported interpretation of the linguistic data with a genetic provenancing approach, GPS, that is at best only suited to inferring the most likely geographic location of modern and relatively unadmixed genomes, and tells nothing of population history and origin." Elhaik's and Das' work was strongly criticized by Marion Aptroot from University of Düsseldorf, among others, who in a study published by Genome Biology and Evolution claimed that "Das et al. create a narrative based on genetic, philological and historical research and state that the findings of the three disciplines support each other...Incomplete and unreliable data from times when people were not counted regardless of sex, age, religion, or financial or social status on the one hand, and the dearth of linguistic evidence predating the 15th century on the other, leave much room for conjecture and speculation. Linguistic evidence, however, does not support the theory that Yiddish is a Slavic language, and textual sources belie the thesis that the name Ashkenaz was brought to Eastern Europe directly from a region in the Near East... certain aspects of the article by Das et al. fall short of established standards". Ancient Israelite DNA As of 2025, the sole study on ancient Israelite DNA pertains to genetic material recovered from the remains of ancient Israelites who lived during the First Temple period. These remains were excavated from the Kiryat Ye'arim site. Professor Israel Finkelstein led the research, during which two individuals - one male and one female - were examined. The study revealed that the male individual belonged to the J2 Y-DNA haplogroup, a set of closely related DNA sequences thought to have originated in the Caucasus or Eastern Anatolia, while the two different mitochondrial DNA identified were T1a9 and H87. The former had previously been documented in an Iron Age Polish site. The latter has been observed in modern Basques, Tunisian Arabs, and Iraqis. ==History==

As early as the 1950s, failed attempts were made to use markers such as fingerprint patterns to characterize Jewish communities. Advances in DNA sequence analysis using algorithms based on "probable common forefathers on the assumption of branching phylogenies" pointed to common progenitors among diverse Jewish communities, as well as overlap with Mediterranean populations. Most researchers now believe that Ashkenazi Jews are descended from both the ancient Israelites and from European converts to Judaism. == See also ==