Genetic studies on the Jews are part of population genetics. This discipline is used to better understand the chronology of migration and thus complements the results provided by history, archeology, language or paleontology. The interest of these studies is to investigate the origins of various Jewish populations today. In particular, they investigate whether there is a common genetic heritage among various Jewish populations.
Y DNA studies show various paternal lineages of modern Jewish populations. Such studies tend to imply a small number of founders in an old population whose members parted and followed different migration paths. These male lines ancestors appear to have been mainly Middle Eastern. For example, Ashkenazi Jews share more common paternal lineages with other Jewish and Middle Eastern groups than with non-Jewish populations in areas where Jews lived in Eastern Europe, Germany and the French Rhine Valley. This is consistent with Jewish traditions in placing most Jewish paternal ancestry either in the region of Canaan, or more generally in the Middle East.
The maternal lineages of Jewish populations, studied by looking at mitochondrial DNA, are generally more heterogeneous. But also concerning this type of DNA there are signs of a dominant contribution from a small number of founders. Most of the time, the geographical or ethnic origin of the maternal line founders is unclear or debatable.
Studies of autosomal DNA, which are a more complete way to judge genetic ancestry, show that the various Jewish populations tend to form relatively closely related groups, which have ancestry in common. For all non Middle-eastern Jewish populations, with the exception of Ethiopian and Indian Jews, this shared component in the ancestry of different Jewish groups has been found to best match modern populations found in the Levant, near modern Israel, Lebanon and Cyprus. This common Jewish ancestry is complemented by significant but varying degrees of admixture with non-Jewish historical host populations. In the case of Ashkenazi, Sephardi and Moroccan Jews, who are apparently closely related, the non-Jewish component is mainly southern European, and an especially close relationship to modern Italians has been remarked by some authors.
2 Paternal lineage, Y chromosome
2.1 Y-DNA of Ashkenazi Jews
2.2 Y-DNA of Sephardi Jews
2.2.1 Y-DNA of Jews from North Africa
2.2.2 Y-DNA of Portuguese Jews
2.2.3 Y-DNA of Oriental Jews
2.2.4 Y-DNA of Roman Jews
2.3 Y-DNA of Kurdish Jews
2.4 Y-DNA of the Jews of Yemen
2.5 Y-DNA of Jews from Ethiopia
2.6 Priestly Families
3 Maternal line: Mitochondrial DNA
3.1 Mt-DNA of Ashkenazi Jews
3.2 Mt-DNA of Jews from North Africa
3.3 Mt-DNA of Jews from the Iberian Peninsula
3.4 Mt-DNA of Jews from Ethiopia
3.5 Mt-DNA of the Jews of Turkey
3.6 Mt-DNA of the Jews of Georgia
3.7 Mt-DNA of Jews from Yemen
3.8 Mt-DNA of Cochin Jews and of Bnei Israel Indian subcontinent
4 Autosomal DNA
5 Comparison with the genetic heritage of non-Jewish populations
5.1 The Samaritans
5.2 The Lembas
5.3 Inhabitants of the Iberian Peninsula
6 See also
7 Notes and references
8 External links
Since the 1970s, many studies have attempted to determine whether, despite the complex history of migrations, it is possible to find common ancestors to the present Jewish communities or if they are rather related to non-Jewish populations who hosted them. The earlier studies attempted to answer this question using "classic" genetic markers (blood groups, enzymes, etc.). Contradictory answers were given according to locus used. One explanation for these contradictions is that the variations associated with a locus are influenced by natural selection.
Since the late eighties and especially since the beginning of the century, geneticists have worked on the Y chromosome (transmitted from father to son) and mitochondrial DNA (transmitted from mother to child), which have the characteristic to be transmitted in full (without recombination). It is therefore possible to trace the common ancestors of various peoples of the world and especially those of Jewish populations. Moreover, very recent studies have been conducted on a large number of genes homologous chromosomes or autosomes (all chromosomes except chromosomes X and Y).
Biologist Robert Pollack stated in 2003 that one cannot determine the biological "Jewishness" of an individual because "there are no DNA sequences common to all Jews and absent from all non-Jews". A 2009 study was able to genetically identify individuals with full or partial Ashkenazi Jewish ancestry.
Paternal lineage, Y chromosome
The first to have shown the existence of a common paternal genetic heritage between Sephardi and Ashkenazi Jews are G. Lucotte and F. David in 1992. In 1993, A. S. Santachiara Benerecetti et al. have suggested the Middle Eastern origin of Jewish paternal lineages.
In 2000, M. Hammer et al. conducted a study on 1371 men and definitively established that part of the paternal gene pool of Jewish communities in Europe, North Africa and Middle East came from a common Middle East ancestral population and suggested that most Jewish communities remained relatively isolated communities compared to non-Jewish neighbor populations in areas where Jews lived in the Diaspora.
In a study of Israeli and Palestinian Muslim Arabs, more than 70% of Jewish men and half of the Arab men whose DNA was studied inherited their Y chromosomes from the same paternal ancestors who lived in the region within the last few thousand years.
Approximately 30% to 40% of Jewish men are in the paternal line known as haplogroup J[Note 1] and its sub-haplogroups. This Haplogroup is particularly present in the Middle East, Southern Europe, and Northern Africa. Furthermore, 15 to 30% are in haplogroup E1b1b[Note 2] (or E-M35) and its sub-haplogroups.
Y-DNA of Ashkenazi Jews
The term "Ashkenazi" is relatively well defined in these studies, it refers to Jews living or whose "paternal" ancestors lived in the following parts of central and eastern Europe: the Rhine Valley, France, Germany, Holland, Austria, Hungary, former Czechoslovakia, Belarus, Lithuania, Poland, Romania, Russia and Ukraine. This excludes the Jews of southern Europe (Balkans, Iberia and Italy) and this also means that non Jews in these regions are outside the definitions used for estimating the genetic make-up of the ancestral "neighbor" or "host" populations of Ashkenazim. (Autosomal studies, discussed below, have more recently compared Ashkenazi to Italians and Greeks and found them to be genetically close.)
All relevant Y DNA studies have concluded that the majority of the paternal genetic heritage among Ashkenazim and other Jewish communities is similar to those found dominating Middle Eastern populations, and probably originated there. A smaller but still significant part of the Ashkenazi male line population is more likely to have originated from central and eastern European populations.
A study of haplotypes of the Y chromosome, published in 2000, addressed the paternal origins of Ashkenazi Jews. Hammer et al. confirmed that the Y chromosome of some Ashkenazi and Sephardi Jews contained mutations that are also common among Middle Eastern peoples, but uncommon in the general European population. This suggested that the male ancestors of the Ashkenazi Jews could be traced mostly to the Middle East. The proportion of male genetic admixture in Ashkenazi Jews amounts to less than 0.5% per generation over an estimated 80 generations, with "relatively minor contribution of European Y chromosomes to the Ashkenazim," and a total admixture estimate "very similar to Motulsky's average estimate of 12.5%." However, when all haplotypes were included in the analysis, the admixture percentage increased to 23% ± 7%.[Note 3] Hammer et al. add that "Diaspora Jews from Europe, Northwest Africa, and the Near East resemble each other more closely than they resemble their non-Jewish neighbors." In addition, of the Jewish populations, the Ashkenazim were closest to South European populations, specifically the Greeks.
Moreover, the frequency of haplogroup R1b in the Ashkenazim population is similar to the frequency of R1b in Middle Eastern populations, but given that haplogroup R1b is particularly abundant in populations of Western Europe, studies of Nebel et al. (2001) and Behar et al. (2004) suggest some Western European contribution to those ~10% of R1b found among Ashkenazim. The largest study made on Ashkenazi Jews, Behar et al. (2004) gives a percentage of 5% - 8% European contribution to the R1b and R1a pool among Ashkenazim.[Note 4] In the words of Behar:
Because haplogroups R-M17 (R1a) and R-P25 (R1b) are present in non-Ashkenazi Jewish populations (e.g., at 4% and 10%, respectively) and in non-Jewish Near Eastern populations (e.g., at 7% and 11%, respectively; Hammer et al. 2000; Nebel et al. 2001), it is likely that they were also present at low frequency in the AJ founding population. The admixture analysis shown in Table 6 suggests that 5%–8% of the Ashkenazi gene pool is, indeed, comprised of Y chromosomes that may have introgressed from non-Jewish European populations.
For G. Lucotte et al., the R1b frequency is about 11%.[Note 5] In 2004, When the calculation is made excluding Jews from Netherlands the R1b rate is 5% ± 11.6%.
Two studies by Nebel et al. in 2001 and 2005, based on Y chromosome polymorphic markers, showed that Ashkenazi Jews are more closely related to other Jewish and Middle Eastern groups than to their host populations in Europe (defined in the using Eastern European, German, and French Rhine Valley populations). However, 11.5% of male Ashkenazim were found to belong to R1a1a (R-M17), the dominant Y chromosome haplogroup in Eastern European populations. They hypothesized that these chromosomes could reflect low-level gene flow from surrounding Eastern European populations, or, alternatively, that both the Ashkenazi Jews with R1a1a (R-M17), and to a much greater extent Eastern European populations in general, might partly be descendants of Khazars. They concluded "However, if the R1a1a (R-M17) chromosomes in Ashkenazi Jews do indeed represent the vestiges of the mysterious Khazars then, according to our data, this contribution was limited to either a single founder or a few closely related men, and does not exceed ~12% of the present-day Ashkenazim.". This hypothesis is also supported by the D. 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.".
Furthermore, 7% of Ashkenazi have the haplogroup G2c, which is extremely rare in the rest of the human population. It seems to be present in a small percentage in the Pashtuns in Afghanistan but the origin of this haplogroup is unknown. The haplogroup Q1b (Q-M378) is also rare in the rest of the human population. It is found in Hazara and Sindhi which are two nomadic tribes in Pakistan. It is also found in the Uyghurs of North-Western China. Behar et al. suggest that those haplogroups are minor Ashkenazi Jews founding lineages.
Among Ashkenazi Jews, Jews of Netherlands seem to have a particular haplogroups distribution since nearly one quarter of them have the Haplogroup R1b1 (R-P25), in particular sub-haplogroup R1b1b2 (R-M269), which is characteristic of Western European populations.
Ashkenazi men show low Y-DNA diversity within each major haplogroup, meaning that compared to the size of the modern population, it seems there were once a relatively small number of men having children. This possibly results from a series of founder events and high rates of endogamy within Europe. Despite Ashkenazi Jews representing a recently founded population in Europe, their founding population probably derived from a large and diverse ancestral source population in the Near East, a population that may have been larger than the source population from which European non-Jews derived.
Haplogroup distribution among Ashkenazim E1b1b1 (M35) G (M201) J1 or J* (12f2b) J2 (M172) Q1 (P36) R1a1a (M17) R1b1 (P25)
Sample number E1b1b1a (M78) E1b1b1c (M123) G2c (M377) J1 (M267) J* J2a* (M410) J2a1b (M67) Q1b (M378) R1b1b2 (M269) R1b1* (P25)
Behar 2004  442 16.1% 7.7% 19% 19% 5.2% 7.5% 10%
Semino 2004 ~80 5.2% 11.7% Not tested 14.6% 12.2% 9.8% Not tested Not tested Not tested
Hammer 2009  large[Note 6] ~3% ~17% ~7% ~17% ~6% ~14% ~7% Not given ~9% ~2%
Nebel 2001 79 23% ? 24% 19% ? 12.7% 11.4%
Shen 2004 20 10% 10% 5% 20% 5% 15% 5% 20% 10%
Y-DNA of Sephardi Jews
The term "Sephardi" refers to significantly different populations from one study to another. It can have a very restrictive meaning and only referring to people speaking Judeo-Spanish (excluding Moroccan Jews) or at the opposite the term Sephardi may designate all non-Ashkenazi populations (excluding Jews from Ethiopia, Yemen and the Kurdish Jews). Between these two extremes, all kinds of variations exist.
Investigations made by Nebel et al. on the genetic relationships among Ashkenazi Jews, Kurdish and Sephardi (North Africa, Turkey, Iberian Peninsula, Iraq and Syria) indicate that Jews are more genetically similar to groups in northern Fertile Crescent (Kurds, Turks and Armenians) than to Arabs.
Y-DNA of Jews from North Africa
The largest study to date on the Jews of North Africa has been led by Gerard Lucotte et al. in 2003. This study showed that the Jews of North Africa[Note 7] showed frequencies of their paternal haplotypes almost equal to those of the Lebanese and Palestinian non-Jews.
The authors also compared the distribution of haplotypes of Jews from North Africa with Sephardi Jews and Ashkenazi Jews and found a common heritage but also significant differences, including the presence of two haplotypes mainly found in Africa. The first haplotype (V)[Note 8], mainly found in North Africa, has a proportion of 18.6% among Jews of North Africa. The authors emphasize that this haplotype appears in similar proportions among the Palestinians (15.9%) and the Lebanese (16.7%). It has a proportion of 3.1% among the Ashkenazi Jews. The second haplotype (IV), mainly found in sub-Saharan Africa, has a proportion of 8.4% among Jews of North Africa and is not found among the Ashkenazi Jews.
The Jewish community of the island of Djerba in Tunisia is of special interest, making the tradition back to the time of the destruction of the First Temple. Two studies have attempted to test this hypothesis first by G. Lucotte et al. from 1993, 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 significant but minority contribution of African lineages, probably Berbers.
Y-DNA of Portuguese Jews
A recent 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 37% lineages more typical of the Near East (J1: 12%, J2-M172: 25% ) and consequently, the Portuguese Jews of this region were genetically closer to other Jewish populations than to Portuguese non-Jews.
N E-M78 E-M81 E-M34 G I J1 J2 T R1a R1b1b1 R1b1b1b2
57 3.5% 5.2% 0% 3.5% 3.5% 12.3% 24.5% 15.8% 1.8% 1.8% 28.1%
Y-DNA of Oriental Jews
Furthermore, Lucotte et al. show that Oriental Jews (Turkey – 19, Greece – 10 Iraq – 12 Iran – 12, Syria – 3) have a similar distribution of haplotypes, but with significant differences in the Lebanese and Palestinian non-Jews.[Note 9]
Y-DNA of Roman Jews
The Roman Jews are as their name suggests Jews were distinguished as originating in Rome, Italy. Mr. Hammer et al. show their paternal lines are close to those of Ashkenazi Jews.
Y-DNA of Kurdish Jews
In the article by Nebel et al. the authors show that Kurdish and Sephardi Jews have paternal genetic heritage indistinguishable. The study shows that mixtures between Kurdish Jews and their Muslim hosts are negligible. Mr. Hammer had already shown the strong correlation between the genetic heritage of Jews from North Africa with their fellow Kurds.
Y-DNA of the Jews of Yemen
The studies of Shen and Hammer et al. show that the genetic father of Yemenite Jews is similar to that of other Jewish populations.
Y-DNA of Jews from Ethiopia
A study of  Lucotte and Smets has shown that the genetic father of Beta Israel (Ethiopian Jews) was close to the Ethiopian non-Jewish populations. This is consistent with the fact that Beta Israel are descendants of ancient inhabitants of Ethiopia, not the Middle East.
Hammer et al. in 2000 and the team of Shen in 2004 arrive at similar conclusions, namely a genetic differentiation in – other people in the north of Ethiopia, which probably indicates a conversion of local populations.
A 2010 study by Behar et al. on the Genome-wide structure of Jews observed that the Beta Israel had similar levels of the Middle Eastern genetic clusters as the Semitic-speaking Tigreans and Amharas. However, compared to the Cushitic-speaking Oromos, who are the largest ethnic group in Ethiopia, the Beta Israel had higher levels of Middle Eastern admixture.
See also: Y-chromosomal Aaron
Dr. Karl Skorecki, a Canadian nephrologist of Ashkenazi origin, remarked that a man who was a Sephardi Cohen like he was had completely different physical characteristics. According to Jewish tradition, all the Cohanim are descendants of the priest Aaron, brother of Moses. Skorecki suggested that if the Cohanim were indeed the descendants of one man, they should have a set of common genetic markers.
To test this hypothesis, he contacted Dr. Michael Hammer of the University of Arizona, a researcher in molecular genetics and a pioneer in research on chromosome. Their article, published in Nature in 1997, has had some impact. A set of special markers (called Cohen Modal Haplotype or CMH) was indeed more likely to be present in the Cohanim, contemporary Jews named Cohen or a derivative, and this is supposed to descend from the ancient priestly lineage than in the Jewish population in general. A common origin had been strictly preserved for thousands of years.
However, 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. tells us that there is no single common haplogroup in all but 21 Cohen haplogroups, and 5 haplogroups are 79.5% of all haplogroups of Cohen. Among these first 5 haplogroups, (J-P58 * or J1E) accounts for 46.1% of Cohen and the second (J-M410 or J2a) of 14.4%. Hammer and Behar have redefined an extended MHC haplotype as determined by a set of 12 markers and having as "background" haplogroup determining the most important lines J1E (46.1%). This haplotype is absent among non-Jews in 2099 analyzed in the study. It appeared there would be a 3000 ± 1000 years. This study nevertheless confirms that the current Cohen descended from a small number of paternal ancestors.
A 2003 study of the Y-chromosome by Behar et al. points 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 speculate that this may indicate a Khazar origin.
Maternal line: Mitochondrial DNA
Studies of mitochondrial DNA of Jewish populations are more recent and are still debatable. However, it seems that there are no maternal lines common to all Jewish people.[Note 10]
Until 2006, geneticists attributed most often the origin of Jewish populations of male individuals who emigrated from the Middle East and taking women as wives in the indigenous populations, who converted to Judaism. However, more recent studies invited to review this claim.
On the other hand, it appears that a number of Jewish community a limited number of women are the source of much of these communities. This phenomenon is called the founder effect. It is rare in non-Jewish communities.
Mt-DNA of Ashkenazi Jews
A 2006 study by Behar et al., based on high-resolution analysis of Haplogroup K(mtDNA), suggested that about 40% of the current Ashkenazi population is descended matrilineally from just four women, or "founder lineages", that were "likely from a Hebrew/Levantine mtDNA pool" originating in the Middle East in the 1st and 2nd centuries CE. Moreover, a maternal line "sister" was found among the Jews of North Africa, France, Italy, and Portugal:
Both the extent and location of the maternal ancestral deme from which the Ashkenazi Jewry arose remain obscure. Here, using complete sequences of the maternally inherited mitochondrial DNA (mtDNA), we show that close to one-half of Ashkenazi Jews, estimated at 8,000,000 people, can be traced back to only four women carrying distinct mtDNAs that are virtually absent in other populations, with the important exception of low frequencies among non-Ashkenazi Jews. We conclude that four founding mtDNAs, likely of Near Eastern ancestry, underwent major expansion(s) in Europe within the past millennium...
Another study done in 2007 by J. Feder et al. confirms the hypothesis of the founding of non-local origin, though their study didn't deal with 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 population, namely Russians, Poles and Germans, concluding 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", and supported previous interpretations of "little or no gene flow from the local non-Jewish communities in Poland and Russia to the Jewish communities in these countries".
Mt-DNA of Jews from North Africa
Analysis of mitochondrial DNA of the Jewish populations of North Africa (Morocco, Tunisia, Libya) has been the subject of further detailed study in 2008 by Doron Behar et al. It shows that Jews from this region do not share the haplogroups of the mitochondrial DNA haplogroups (M1 and U6), which are typical of the North African of Berber and Arab populations. Similarly, while the frequency of haplogroups L, associated with sub-Saharan Africa, are around an average of 20–25% at the Berber populations studied, it is only 1.3%, 2.7% and 3.6% respectively among Jews from Morocco, Tunisia and Libya.
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". This study also found genetic similarities between the Ashkenazi and North African Jewish mitochondrial DNA pools, but differences between both of these and Jews from the Middle East. Instead, the study found that about 40% of Libya's Jews are descendants of one woman along their maternal lines and that 43% of Tunisian Jews descended from 4 women along their maternal lines.
Mt-DNA of Jews from the Iberian Peninsula
The data (mt-DNA) recovered by D. Behar et al. are located in the village of Belmonte in Portugal in a community descended from crypto-Jews. It is not possible to generalize the entire Iberian Peninsula.
Mt-DNA of Jews from Ethiopia
The results are similar to those of the male population, namely genetic characteristics identical to those of surrounding populations.
Mt-DNA of the Jews of Turkey
Mt-DNA of the Jews of Turkey is extremely divergent which means that the genetic mother is from very different origins. It is interesting to note that an Iberian type lineage has been found which is consistent with historical data.[Note 11]
Mt-DNA of the Jews of Georgia
According to the study of G. Thomas et al. 51% of Georgian Jews descended from a single female (58% according to Behar ). Unfortunately, once again it is not possible to determine the origin of this lineage.
Mt-DNA of Jews from Yemen
In a study by Richards et al., authors suggest that a minor proportion of haplogroup L1 and L3A lineage from sub-Saharan Africa is present among Jews from Yemen. However, these lines are 4 times smaller in proportion than among non-Jewish Yemenis. These sub-Saharan haplogroups are virtually absent among Jews from Iraq, Iran and Georgia and are completely absent among Ashkenazi Jews.
The Jewish population of Yemen also has a founder effect. 42% of maternal lines come from 5 women originating in western Asia for 4 of them and sub-Saharan Africa for the last.
Mt-DNA of Cochin Jews and of Bnei Israel Indian subcontinent
According to the study of 2008 D. Behar et al., it is clear that the maternal lineage of the Jews of India has a local origin for the vast majority of the community. However, it appears that the maternal gene pool still includes a maternal lineage of origin Iraqi / Iranian or Italian.
These studies focus upon autosomal chromosomes, the 22 homologous or autosomes (non sex chromosomes), rather than on the paternal or maternal lines.
An initial study conducted in 2001 by N. Rosenberg et al. on six Jewish populations (Poland, Libya, Ethiopia, Iraq, Morocco, Yemen) and two non-Jewish populations (Palestinians and Druze) shows that while the eight groups are close, the Jews of Libya have a genetic signature separate from their genetic isolation and a possible combination with Berber populations.[Note 12] This same study suggests a close relationship between Jews of Yemen and those of Ethiopia.
A 2006 study by Seldin et al. used over five thousand autosomal SNPs to demonstrate 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".
A 2007 study by Bauchet et al. found that Ashkenazi Jews were most closely clustered with Arabic North African populations when compared to Global population, and in the European structure analysis, they share genetic similarities with Greeks and Southern Italians, reflecting their east Mediterranean origins.
In a 2009 study by Kopelman et al., Ashkenazi Jews, Turks, Moroccans and Tunisians, share a common origin from the Middle East and are quite close to Palestinians. However, in this study, the Tunisian Jews are distinct from three other Jewish populations, which might tend to suggest, according to the authors, a greater genetic isolation and/or a significant contribution of local Berber as in the case of Libyan Jews. In this study, the authors also state, on the hypothesis of the origin of Ashkenazi Jews, that they did not detect differences between Ashkenazi Jews and other Jewish populations. Nonetheless, they detected a similarity between the Adyghe people (a group of Caucasus whose land was formerly occupied by the Khazars) and Jewish populations studied, as was observed by Need et al. in another study. In conclusion, the authors of this study found that "different Jewish population groups show a high level of genetic similarity to each other, clustering together in several types of analysis of population structure." The authors explained this similarity as a result of a shared ancestry with an ancestral Middle Eastern group
Another study of L. Hao et al. (October 2009) studied seven groups of Jewish populations with different geographic origin (Ashkenazi, Italians, Greeks, Turks, Iranians, Iraqis and Syrians) showed that the individuals all shared a Middle Eastern background in common, although they were also genetically distinguishable from each other. This distinction, it was once again suggested, reflects mixtures with different local populations. Thus, among the Jewish populations studied, the authors detected a European contribution ranging from 30% to 60% among Syrian Jews, Sephardim and Ashkenazim, which was virtually absent in the Iranian and Iraqi Jews. The same authors (Atzmon et al. June 2010) demonstrated that European/Syrian and Middle Eastern Jews represent a series of geographical isolates or clusters woven together by shared IBD (identity by descent) genetic threads. Each of the groups in the study demonstrated Middle Eastern ancestry as Middle Eastern Jews and European/Syrian Jews seems to share common ancestors in the Middle East about 2500 years ago. The study examines genetic markers spread across the entire genome and shows that the Jewish groups (Ashkenazi and non Ashkenazi) share large swaths of DNA, indicating close relationships and that each of the Jewish groups that were studied (Iranian, Iraqi, Syrian, Italian, Turkish, Greek and Ashkenazi) has its own genetic signature but is more closely related to the other Jewish groups than to non-Jewish groups. The study also found that with respect to non-Jewish European groups, the population most closely related to Ashkenazi and Syrian Jews are modern-day Italians. The study speculated that the genetic-similarity between Ashkenazi/Syrian Jews and Italians may be due to inter-marriage and conversions in the time of the Roman Empire. It was also found that any two Ashkenazi Jewish participants in the study shared about as much DNA as fourth or fifth cousinsHarry Ostrer, the director of the Human Genetics Program at NYU Langone Medical Center, and one of the author of this study, concluded "We have shown that Jewishness can be identified through genetic analysis, so the notion of a Jewish people is plausible. "Dr. Ostrer noted, "The study supports the idea of a Jewish people linked by a shared genetic history".
In addition, the genetic proximity of European/Syrian Jewish populations, including Ashkenazi Jews, to each other and to French, Northern Italian, and Sardinian populations favors the idea of possible non-Semitic Mediterranean contribution in the formation of the European/Syrian Jewish groups and is incompatible with theories that Ashkenazi Jews are for the most part the direct lineal descendants of converted Khazars or Slavs. It refutes large-scale genetic contributions of Central and Eastern European and Slavic populations to the formation of Ashkenazi Jewry. Other authors have previously shown the genetic proximity between Ashkenazi and Southern European population (Cf. table below and discussion above).
Autosomal genetic distances (Fst) based on SNPs  Italians Greeks Spanish Germans Druze Palestinians Irish Russians
Ashkenazi 0.0040 0.0042 0.0056 0.0072 0.0088 0.0093 0.0109 0.0137
The Iranian and Iraqi Jews are the most differentiated with the greatest genetic distances from the other populations and the least distances from each other. They have a high coefficient of inbreeding. A certain degree of admixture may have occurred with local populations.
In June 2010, Behar et al. "shows that most Jewish samples form a remarkably tight subcluster 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 neighbouring 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's et al. using SNP microarray techniques and linkage analysis "confirms that there is a closer relationship between the Ashkenazim and several European populations (Tuscans, Italians, and French) than between the Ashkenazim and Middle Eastern populations" and that European "admixture is considerably higher than previous estimates by studies that used the Y chromosome" adding that their study "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 perhaps even more similar with Europeans than modern Middle Easterners. The level of admixture with European population was estimated between 35 to 55%. The study assumed Druze and Palestinian Arabs populations to represent the reference to 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". Nevertheless, the authors indicated that possible Achilles' heel for their conclusions is that their calculations might have "overestimated the level of admixture" in case that the true Jewish ancestors were genetically closer to Southern Europeans than Druze and Palestinian Arabs are and predicted that using the non Ashkenazi Jewish Diaspora populations as reference for world Jewry ancestor genome would "underestimate the level of admixture", since they find it reasonable that the non Ashkenazi Jewish Diaspora has also "undergone the similar admixture" compared to Ashkenazi Jews.
Zoossmann-Diskin (2010) is critical of the interpretations made by other authors of autosomal DNA data from Jewish populations. He argues, despite using a comparatively limited amount of autosomes, that based upon X chromosome and autosomal DNA evidence, 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 believes the evidence points to a dominant amount of southern European, and specifically Italian, ancestry, which he argues is probably a result of conversions during the Roman empire. Concerning the similarity between Sephardi and Ashkenazi, he argues that the reasons are uncertain, but that it is likely to be caused by Sephardic Jews having "Mediterranean" ancestry also, like the Ashkenazi. Concerning mitochondrial DNA, and particularly Y DNA, he accepts that there are superficial signs of a Middle Eastern origins, but he argues that this can be ignored as it is may came from a small number of ancestors.
In 2011, Moorjani et al. show to have detected 3%–5% sub-Saharan African ancestry in all eight of the diverse Jewish populations (Ashkenazim, Syrian Jews, Iranian Jews, Iraqi Jews, Greek Jews, Turkey Jews, Italian Jews) that they analyzed. Researchers from the Harvard Medical School estimate that the exchange of genes occurred approximately 72 generations ago (or about 2,000 years). Lawrence Schiffman, professor of Hebrew and Judaic studies at Yeshiva University, believes the intermixing may have occurred during the Hellenistic period (c. 320–30 B.C.E.), when Jewish communities were resident in many North African coastal cities, or during the First Temple period (c. 950–600 B.C.E.), when the Israelite kings, including Solomon, had trade relationships with Africa.
Comparison with the genetic heritage of non-Jewish populations
Further information: Samaritans
The Samaritans are an ancient northern population of historic Palestine, where they are historically well identified since at least the 4th century BC. They define themselves as the descendants of tribes of Ephraim and Manasseh (two tribes from the Tribe of Joseph) living in the Kingdom of Israel before its destruction in 722 BC. For them, the Jews are the descendants of the Israelites from ancient southern kingdom of Judah (and Jerusalem).
A 2004 study by Shen et al. compared the Y-DNA and DNA-mt Samaritans of 12 men with those of 158 men who were not Samaritans, divided between 6 Jewish populations (Ashkenazi origin, Moroccan, Libyan, Ethiopian, Iraqi and Yemeni) and 2 non-Jewish populations from Israel (Druze and Arab). The study concludes that significant similarities exist between paternal lines of Jews and Samaritans, but the maternal lines differ between the two populations. The pair-wise genetic distances (Fst) between 11 populations from AMOVA applied to the Y-chromosomal and mitochondrial data. For the Y-chromosome, all Jewish groups, except for the Ethiopians, are closely related to each other. They do not differ significantly from Samaritans (0.041) and Druze (0.033), but are different from Palestinians (0.163), Africans (0.219), and Europeans (0.111). Nevertheless, the data in this study indicated that the Samaritan and Jewish Y-chromosomes have a greater affinity than do those of the Samaritans and their geographical neighbors, the Palestinians.
The Lemba clans are scattered among the Bantu-speaking tribes in Zimbabwe and northern South Africa. The oral tradition traces the origin of the Jewish Lembas to Saana in Yemen. Some practices seem reminiscent of Jewish practices (circumcision, food law,…). Two studies have attempted to determine the paternal origin of these tribes. The first by A. Spurdle and T. Jenkins dates from 1996 and suggests that more than half of Lembas tested are of Semitic origin.[Note 13] The second study by Mark G. Thomas et al. dates from 2000 and also suggests that part of Lembas have a Semitic origin that can come from a mixture of Arab and Jewish.[Note 14] In addition, the authors show that clans Lemba (Buba clan) has a large proportion of the former CMH.
Inhabitants of the Iberian Peninsula
According to a 2008 study by Adams the inhabitants of the Iberian Peninsula have an average of 20% of Sephardi Jewish ancestry with significant geographical variations ranging from 0% on Minorca to 36.3% in southern Portugal (the term Sephardi is used here in its strict sense to mean the Jews settled in the Iberian peninsula before the expulsions in and after 1492). Part of this admixture might also, according to the authors, be of Neolithic origin.