North African Jewish and non-Jewish populations form distinctive, orthogonal clusters

Abstract

North African Jews constitute the second largest Jewish Diaspora group. However, their relatedness to each other; to European, Middle Eastern, and other Jewish Diaspora groups; and to their former North African non-Jewish neighbors has not been well defined. Here, genome-wide analysis of five North African Jewish groups (Moroccan, Algerian, Tunisian, Djerban, and Libyan) and comparison with other Jewish and non-Jewish groups demonstrated 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.

Jews lived in multiple communities in North Africa for >2,000 y (1). Successive waves of migration from the Middle East and Europe, as well as conversion and admixture of local populations (mostly thought to be Berber and here termed “Maghrebi”), contributed to the formation of Jewish communities (2). Although termed “Sephardic,” the formation of these communities antedated the presence of Jews in the Iberian Peninsula with significant admixture occurring only after the expulsions from Spain and Portugal in 1492 and 1497, respectively (2). From that time up to their migration to current Israel starting in the 1940s and more massively in the 1950s, each of these populations lived in relative seclusion and was endogamous (3, 4). This separation led to their developing the characteristics of genetic isolates, such as high frequencies of founder mutations for Mendelian disorders and limited repertoires of mitochondrial and Y chromosomal haplotypes (5–7).

The relatedness of these Jewish groups to each other, to European and Middle Eastern Jews, and to their non-Jewish North African neighbors has been addressed in only a fragmentary fashion in prior studies (8–14). Most studies were limited to one or two North African groups. One study challenged the story line of Judean migrants, Berber tribesmen, and Sephardic Jewish refugees contributing to the formation of these groups by demonstrating shared ancestry between Libyan Jews and Yemenite and Ethiopian Jews—groups that are thought to have limited Middle Eastern Jewish ancestry (15).

Previously, using genome-wide SNP and copy number variation data, we demonstrated that Sephardic (Greek and Turkish), Ashkenazi (Eastern European), and Mizrahi (Iranian, Iraqi, and Syrian) Jews with origins in Europe and the Middle East were more related to each other than to their non-Jewish contemporary neighbors (16). We showed that this relatedness could be explained on the basis of sharing DNA segments identical by descent (IBD) within and between populations. Here, we build on this understanding of the Jewish Diasporas by extending our analyses to members of the Jewish communities in Morocco, Algeria, Tunisia, Djerba, Libya, Ethiopia, Yemen, and Georgia and to members of non-Jewish communities from the same regions. We present a comprehensive population genetic analysis of North African Jews, a group that comprises the third major group of World Jewry, following European and Middle Eastern Jews. In addition, we extend these analyses to Georgian, Yemenite, and Ethiopian Jews, thus developing a more comprehensive genetic map for Jewish population genetics.

Results

North African Jewish Populations Form Distinctive Clusters with Genetic Proximity to Each Other and to European and Middle Eastern Jewish Groups.

SNP data were generated for 509 unrelated individuals (60.5% female) from the 15 Jewish populations (Table 1). These SNP data were merged with selected datasets from the Human Genome Diversity Project (HGDP) to examine the genetic structure of Jewish populations in both global and regional contexts (Fig. 1 and SI Appendix, Fig. S1). The first two principal components of worldwide populations showed that the North African Jewish populations clustered with the European and Middle Eastern Jewish groups and European non-Jewish groups, but not with the North African non-Jewish groups, suggesting origins distinctive from the latter (Fig. 1A). Georgian Jews formed part of this cluster, whereas Yemenite and Ethiopian Jews did not. When compared only to the European, Middle Eastern, and North African Jewish and non-Jewish populations, the North African Jewish populations formed a common but distinctive cluster—observed by principal components 1 and 2—that was overlapping with the Greek and Turkish Sephardic Jewish cluster (Fig. 1B). Each of these Jewish groups, in turn, formed a distinctive cluster—observed by principal components 1 and 3—that demonstrated a west to east cline with Algerian and Moroccan Jews in proximity to the Sephardic Jewish populations. The Tunisian Jews exhibited two apparent clusters—one with proximity to Libyan and Djerban Jews and the other proximal to the Moroccan and Algerian Jews (Fig. 1C).

Table 1.

Summary of populations included in this study

Population ID	Female	Male	Total	Population
ALGJ	23	1	24	Algerian Jewish
ASHJ	14	20	34	Ashkenazi Jewish*
DJEJ	0	17	17	Djerban Jewish
ETHJ	13	3	16	Ethiopian Jewish
GEOJ	4	9	13	Georgian Jewish
GRKJ	25	29	54	Greek Jewish*
IRNJ	22	27	49	Iranian Jewish*
IRQJ	25	28	53	Iraqi Jewish*
ITAJ	20	19	39	Italian Jewish*
LIBJ	31	6	37	Libyan Jewish
MORJ	32	6	38	Moroccan Jewish
SYRJ	15	21	36	Syrian Jewish*
TUNJ	24	5	29	Tunisian Jewish
TURJ	24	10	34	Turkish Jewish*
YMNJ	36	0	36	Yemini Jewish
ADYG	10	7	17	Adygei
ALGE	9	9	18	Algerian
BASQ	8	16	24	Basque
BEDN	20	27	47	Bedouin
DRUZ	32	13	45	Druze
EGYP	0	19	19	Egyptian
FREN	17	12	29	French
LIBY	1	16	17	Libyan
MORN	0	18	18	North Moroccan
MORS	5	5	10	South Moroccan
MOZA	9	19	28	Mozabite
NITA	7	14	21	Northern Italian
PALN	34	17	51	Palestinian
RUSS	9	16	25	Russian
SARD	12	16	28	Sardinian
SOCC	0	17	17	Saharan
TUNI	0	15	15	Tunisian
AFRI	1	24	25	Sub-Saharan African
ASIA	10	15	25	Asian

*Samples that were genotyped and reported in Atzmon et al. (16).

Fig. 1.

Principal component analysis (PCA) of Jewish populations combined with other HGDP groups in global (A) and regional contexts (B and C). Dense regions with many overlapping populations are circled for the purpose of illustration, with a list of the groups adjacent.

The neighbor-joining tree supported this clustering of the Jewish populations, with the previously described European/Syrian and Middle Eastern branches being discernible (Fig. 2). The European Turkish, Greek, and Italian Jews shared a common branch, with Ashkenazi and Syrian Jews forming connections to this branch. The North African populations added a subbranch to the European/Syrian branch, which in turn bifurcated into Moroccan–Algerian and Tunisian–Djerban–Libyan subbranches. As reported previously (16), the Middle Eastern Jewish branch included the Iranian and Iraqi Jews and the non-Jewish Adygei. This branch was observed now to include Georgian Jews. The Yemenite and Ethiopian Jews were on distinctive branches with the Yemenite Jews on a branch between Palestinians and Bedouins. The robustness of this phylogenetic tree was demonstrated by the fact that a majority of branches were supported by >90% of bootstrap replications.

Fig. 2.

Neighbor-joining tree showing the relationship of European, Jewish, Middle Eastern, and North African populations, using F_ST as the distance metric. The tree was rooted by using the reference mixed Central and Southern African population as an out-group. Major population groups are labeled at the right, with the red bar within the Jewish group denoting North African Jews. Five hundred bootstrap iterations were tested to assess the robustness of the tree [the labels at the nodes represent the number of iterations (%) in which that configuration was seen]. Populations labeled with an asterisk (*) cluster outside of their expected groups.

Pairwise F_ST analysis indicated that each of the North African Jewish populations was distinct and, by bootstrap analysis, statistically different from all of the others [SI Appendix, Tables S1 (upper triangle) and S2]. Although F_ST may be sensitive to small sample sizes, these population differences were confirmed by ANOVA on the principal component analysis (PCA) eigenvectors (P < 0.05; SI Appendix, Table S3), with the exception of Algerian and Moroccan Jews, who were found to overlap. These differences were also confirmed by permutation testing of between-group IBS for all pairwise comparisons of the 15 Jewish populations (SI Appendix, Table S5). In addition, the exact test for population differentiation indicated that these populations were significantly different (P < 0.001)—again with the exception of Algerian and Moroccan Jews (P = 0.25). These findings demonstrated that the most differentiated of the North African Jewish populations was Djerban (average F_ST to all other Jewish populations 0.026). The smallest F_ST was between Greek and Turkish Sephardic Jews (F_ST = 0.0024), who were close, in turn, to Italian, Algerian, Moroccan, and Ashkenazi Jews. The second smallest F_ST observed was between Algerian and Moroccan Jews (F_ST = 0.0027). As a point of reference, the average pairwise F_ST between Jews and non-Jews (excluding African and Asian reference populations) was 0.019. Thus, North African Jews were identifiable as a third major group along with Middle Eastern Jews and European/Syrian Jews, albeit with a higher degree of relatedness to European Jews.

North African Jewish Populations Showed a High Degree of Endogamy and IBD Sharing Between Jewish Groups.

We studied the frequency of IBD haplotypes shared by unrelated individuals within and across the groups analyzed. When IBD within populations was examined, the non-Jewish Tunisian Berbers exhibited the highest level of haplotype sharing, suggesting a small effective population size and high levels of endogamy (Fig. 3A) (17, 18). With the exception of this Tunisian cohort, the Jewish populations generally showed higher IBD sharing than non-Jewish groups, indicating greater genetic isolation.

Fig. 3.

Genome-wide IBD sharing for the average pair of individuals within (A) and across (B and C) populations. With the exception of non-Jewish Tunisian samples, IBD sharing is higher within Jewish groups, reflecting higher levels of endogamy. Jewish populations exhibit higher sharing with other Jewish populations than with geographically near groups, The average total sharing across Jewish populations is generally higher than the sharing across other population pairs, and pairs of North African Jewish populations (dark to red color bars) share more segments IBD than most other Jewish pairs.

The relationships of the Jewish communities were outlined further by the IBD sharing across populations [Fig. 3B and SI Appendix, Tables S1 (lower triangle) and S4], because the Jewish groups generally demonstrated closer relatedness with other Jewish communities than with geographically near non-Jewish populations. In particular, North African Jewish communities showed some of the highest levels of cross-population IBD sharing for the average pair of individuals (SI Appendix, Fig. S5). A strong degree of relatedness was observed across individuals from the Djerban, Tunisian, and Libyan Jewish communities. Noticeable proximity was also found between Jewish Algerian samples and other North African Jewish cohorts—such as Moroccan, Tunisian, Libyan, and Djerban Jews—and across individuals from the Tunisian and Moroccan Jewish groups. Among non-Jewish North African groups, Algerians, South Moroccans, and West Saharan samples were found to share, on average, a smaller proportion of their genome IBD to other cohorts.

North African Jewish and Non-Jewish Populations Vary in Their Proportions of European and Middle Eastern Ancestry.

By STRUCTURE analysis, the North African Jewish groups demonstrated inferred North African–Middle Eastern ancestry with varying inferred European ancestry (Fig. 4 and SI Appendix, Fig. S2). The proportion of inferred European ancestry increased from east to west, with Moroccan Jews demonstrating the highest proportion. In contrast, the neighboring non-Jewish North African populations demonstrated substantially higher inferred North African ancestry and less European ancestry. In addition, these neighboring non-Jewish populations showed inferred sub-Saharan ancestry that was not demonstrable by STRUCTURE analysis in the North African Jewish populations. Reflecting the high degree of relatedness and shared ancestry among Tunisian, Djerban, and Libyan Jews, a unique (red) component was observed at K = 6 and 7. Similarly, reflecting the high degree of relatedness and shared ancestry among Iranian and Iraqi Jews, a unique (green) component was observed at K = 7.

Fig. 4.

STRUCTURE results for Jewish populations combined with Middle Eastern, European, East Asian, and African populations from HGDP. K values of 3–7 are shown; each represents an alignment of 10 independent runs. Vertical bars represent individuals, which are grouped by their known populations and further combined into general regional groups, illustrated by the top bar.

By using Xplorigin to perform ancestry deconvolution for a subset of the populations, the Maghrebi (Tunisian non-Jewish), European (Basque), and Middle-Eastern (Palestinian) ancestry components of North African Jewish communities were compared with the corresponding non-Jewish groups (Fig. 5). A stronger signal of European ancestry was found in the genomes of Jewish samples, with a decreased fraction of Maghrebi origins, whereas the Middle Eastern component was comparable across groups. In Jewish groups, geographical proximity to the Iberian Peninsula correlated with an increase in European ancestry and a decrease in Middle Eastern ancestry, whereas the Maghrebi component was only mildly reduced. Differences in ancestry proportions were found to be significant (P < 0.05), except for the Maghrebi component of non-Jewish Northern Moroccan compared with non-Jewish Algerian samples, and the European component of Jewish Moroccan compared with Jewish Algerian samples.

Fig. 5.

Ancestry deconvolution. The genome-wide ancestry of North African Jewish and non-Jewish populations is compared with respect to European (Basque), Maghrebi (Tunisian non-Jewish), and Middle Eastern (Palestinian) origins. Jewish populations exhibit increased European and decreased Maghrebi ancestry compared with corresponding non-Jewish groups. The Middle Eastern component is comparable across all groups.

Given the distinctive genetic identity of the Basque population compared with other European populations (19), we also ran the Xplorigin analysis using 48 randomly selected HGDP Russian haplotypes as a reference for the European ancestral component of the analyzed populations. The results of such analysis suggested that, although the estimated European components using Basque or Russian reference genomes were correlated, short haplotype frequencies found in the Russian samples were less representative of the analyzed groups’ European ancestry (Fig. 5 and SI Appendix, Fig. S6).

In addition to genome-wide proportions, this ancestry painting analysis was intersected with regions that harbor long-range IBD haplotypes. The ancestry of these loci likely reflects more recent demographic trends, because long IBD haplotypes are coinherited from more recent common ancestors than the average genomic locus. In Jewish populations, the ancestry proportions in corresponding IBD regions highlighted mild—but in some cases significant—deviations from genome-wide averages (SI Appendix, Fig. S3; detail in SI Appendix, Table S6), whereas stronger differences were observed in the recent ancestry for the corresponding non-Jewish communities. In these groups, recently coinherited regions exhibited significantly increased European ancestry, with significantly decreased Maghrebi ancestry, compared with genome-wide averages. This phenomenon was generally stronger for loci shared IBD with individuals from Jewish communities. This increase in European ancestry and corresponding decrease in Maghrebi ancestry may be interpreted in several ways: (i) This increase may be due to the inherently higher European ancestry of Jewish segments planted into the genomes of non-Jewish populations. (ii) Alternatively, the difference in genome-wide ancestries between Jewish and non-Jewish groups alone could explain this observation in the case of recent symmetric gene flow in both directions. However, this second scenario alone is inconsistent with the data, because it would imply a comparable decrease of European ancestry in regions IBD to non-Jewish populations to be observed in Jewish genomes. (iii) The observed increase of European ancestry could be similarly explained by European segments newly planted in both populations. This explanation is also unlikely, because it would result in a comparable increase of European ancestry in Jewish genomes, which is instead observed to only mildly increase compared with genome-wide averages. The increase in European ancestry is stronger in IBD regions of length between 3 and 4 cM, compared with regions at least 4 cM long (SI Appendix, Table S7), which is compatible with European admixture occurring several generations before present, through ancestors that resided in the Iberian Peninsula.

Ethiopian and Yemenite Jewish Populations Form Distinctive Clusters, Whereas Georgian Jews Do Not.

As noted, by PCA, Georgian Jews formed part of the Jewish cluster, whereas Yemenite and Ethiopian Jews did not. ANOVA on the PCA eigenvectors and pairwise F_ST analysis indicated that the Ethiopian, Yemenite, and Georgian Jewish populations were distinct and statistically different from all of the others [SI Appendix, Tables S1 (upper triangle), S2, and S3]. Ethiopian Jews fell outside of the main three Jewish genetic clusters with the highest average genetic differentiation compared with all other Jewish groups (F_ST = 0.047). They were most closely related to non-Jewish Libyans and South Moroccans (F_ST = 0.019) and then to the other North African and Middle Eastern non-Jewish populations. Their closest (yet still quite distant) Jewish neighbors were Yemenite Jews (F_ST = 0.038). Likewise, they showed little IBD sharing with other Jewish populations (Fig. 3). By STRUCTURE analysis, their ancestry appeared to be of North African, Middle Eastern, and sub-Saharan origin with little European contribution (Fig. 4).

Despite forming a cluster on PCA and neighbor-joining tree that appeared intermediate to Jews and Middle Eastern non-Jews, the Yemenite Jews were genetically closest to Egyptians by F_ST (0.008), followed by Middle Eastern non-Jews, then Turkish and Greek Jews (F_ST = 0.010 and 0.012, respectively); however, their mean F_ST to all other Jewish populations was similar to that of all other Jewish populations with the exception of Ethiopian Jews (SI Appendix, Fig. S4). Their mean levels of IBD sharing with Jewish populations were comparable to the mean levels of IBD sharing of other Jewish populations, except Ethiopian Jews (SI Appendix, Fig. S4). By STRUCTURE analysis, their inferred ancestry was predominantly Middle Eastern and North African with little European contribution.

As noted, the Georgian Jewish cluster overlapped the overall Jewish cluster, and the Georgian Jewish subbranch on the neighbor-joining tree was intermediate to those of Iranian and Iraqi Jews and the Adygei. The Georgian Jews had a low F_ST compared with Sephardic Jews (mean F_ST = 0.009), despite their similarity with Iranian and Iraqi Jews in the neighbor-joining tree and PC analysis. By pairwise IBD sharing with other Jewish populations, the Georgian Jews fell within the pattern of Jewish relatedness. By STRUCTURE analysis, their inferred ancestry was predominantly Middle Eastern and European, with little North African contribution. Notably, they shared a small proportion of the unique K = 7 (green) component that was observed in the Iranian and Iraqi Jewish populations, which may be due to either small sample size or genetic drift and founder effect.

Discussion

This study supports and expands the classification of Jewish populations that has been developed by us and others (14–16). It defines North African Jews as a distinct branch with significant relatedness to European and Middle Eastern Jews, with both being part of a larger Jewish cluster. Within this branch are two subbranches—the highly endogamous and related Djerban, Libyan, and Tunisian Jews and the more European Algerian and Moroccan Jews. With these methods, the Tunisian Jews could be differentiated into two subclusters by PCA that were more Libyan/Djerban-related and more Moroccan/Algerian-related, and the Moroccan and Algerian Jews could be demonstrated to be no different from a single population by F_ST and the exact test of population differentiation. All of these populations were differentiated from the current non-Jewish populations in these countries reflecting distinctive genetic histories.

These observations are consonant with the history of Jews in North Africa, which stretch back to the earliest recorded history of the region (1–4, 20). Israelite traders may have been among the earliest Phoenician traders who colonized the African coast and established Carthage. The first evidence for Jews in North Africa is from 312 Before Common Era when King Ptolemy Lagi of Egypt settled Jews in the cities of Cyrenaica in current-day Tunisia. The later Pax Romana facilitated communication among the Jewish communities of the Mediterranean Basin and assured establishment of Judaism in the two African provinces of Proconsular (Libya and Tunisia) and Caesarean (Algeria and Morocco)—reflecting the current subbranches. Following the destruction of the Second Temple in Jerusalem by Roman Emperor Titus in 70 Common Era (CE), 30,000 Jews were deported to Carthage in current-day Tunisia. Josephus reported the presence of 500,000 Jews in Cyrenaica in the 1st century CE. Jewish communities have been identified from the synagogue remains at Carthage and at least 13 other sites, and Saint Augustine wrote about Jewish communities at Utica, Simittra, Thusurus, and Oea. Thus, Jewish communities originated in pre-Classical Antiquity and expanded during Classical Antiquity to grow quite large and cover a significant proportion of North Africa.

As demonstrated from these analyses, both admixture and isolation with endogamy contributed to the formation of these groups. Judaism is thought to have spread among the indigenous Berbers of North Africa through proselytism, which was quite common at the time, although the degree to which it occurred is unknown. Significant admixture occurred with the Sephardic Jews of Spain following their expulsion during the Inquisition in 1492 and later, when tens of thousands migrated to the Mahgreb (Morocco, Algeria, and Tunisia) and fewer went elsewhere. This admixture is reflected in the higher proportion of European ancestry among Moroccan and Algerian Jews and the greater genetic proximity of these groups and high degree of IBD segment sharing with Sephardic Greek, Turkish, and Italian Jews. Admixture occurred with North African non-Jewish populations. However, as demonstrated by the apparent unrelatedness of the Jewish and non-Jewish North Africans, these events were not recent.

Isolation began for Jews when Roman Emperor Constantine converted to Christianity and made it the state religion of the Roman Empire. In the process, Jews were deprived of their right to convert pagans or accept proselytes. Most Christian communities of North Africa disappeared following the Arab conquest of the 8th century CE. The Jewish communities remained, but were subject to religious and civil suppression. The Jews tended to live in their own special quarters, and the area as a whole was fragmented into small tribal states. The resulting high degree of endogamy within the North African Jewish populations is reflected in the high degree of within-population IBD sharing, the patterns of within-population rare Mendelian disorders, and the identification of a shared inferred ancestral component among the Djerban, Tunisian, and Libyan Jews by STRUCTURE, neighbor-joining tree, and, to a less obvious degree, PCA. Such a uniquely shared inferred ancestral component was also observed among the Middle Eastern/Caucasian–Iranian, Iraqi, and Georgian Jews.

These results are in agreement with previous population genetic studies of North African Jews, yet significantly expand their observations by using larger numbers of populations and contemporary methods. Earlier studies based on blood group markers and serum proteins differentiated North African Jews from other Jewish groups and from non-Jewish North Africans (8–13). A more recent study identified a distinctive signature for Libyan Jews (15). Here, this signature was confirmed and shown to be shared by Djerban and Tunisian Jews. A global study of Jewish population genetics from 2010 that partitioned most Jewish genomes into Ashkenazi–North African–Sephardic, Caucasus–Middle Eastern, and Yemenite subclusters demonstrated that an Ethiopian subcluster was close to the local population, in accordance with what was observed here (14). A previous study of monoallelic matrilineal inheritance demonstrated limited mitochondrial lineages in Tunisian and Libyan Jews, but not in Moroccan Jews, which was observed in this study as a high degree of extended IBD sharing among the more endogamous Tunisian and Libyan populations (5).

The observations for Georgian and Ethiopian Jews met historical expectations—Georgian Jews are an outgrowth from the Iranian and Iraqi Jewish communities, and Ethiopian Jews are an ancient community that had relatively few, if any, Jewish founders from elsewhere and existed in isolation for >2,000 years. Nonetheless, the low F_ST between Sephardic and Georgian Jews suggests that the latter may have had significant contact with Turkish or Syrian Jews. The observations for the Yemenite Jews are even more surprising. Like the Ethiopian Jews, this population was founded >2,000 y ago and was thought to be comprised mostly of local proselytes, which is reflected in the distinctive clustering of the population away from other Jewish groups and the mostly Middle Eastern ancestry present in this group. However, the observation of comparable F_ST and IBD sharing with other Jewish communities implies significant common Jewish founders in the absence of more recent genetic flow into the community. Thus, although Jewishness was transmitted by the flow of ideas and genes, both appear to have been under selection for long periods of time.

Materials and Methods

More detailed methods are described in SI Appendix, SI Materials and Methods.

Genotype Data.

A total of 509 Jewish samples from 15 populations were genotyped on the Affymetrix 6.0 array (Affy v6). These were combined with 114 non-Jewish individuals from seven North African populations (17) by using the same array and 365 samples genotyped in the HGDP (21), by using Illumina HumanHap650K Beadchips. After merging and quality-control filtering, a total of 163,199 high-quality SNPs were available for downstream analyses.

PCA, F_ST, and Phylogeny.

The SMARTPCA program from the EIGENSOFT package (Version 3.0) (22) was used to perform outlier removal and PCA. F_ST values were calculated for each population pair by using Genepop (23). A bootstrap method, sampling all markers with replacement for 500 iterations, was used to estimate F_ST confidence intervals and to generate a consensus tree using the neighbor-joining method from PHYLIP (Version 3.69) (24). Genepop was also used to perform an exact test of population differentiation.

Population Structure.

Population ancestry proportions were inferred by using the program STRUCTURE (Version 2.3) (25, 26). A selection of 5,113 markers was used, selected for high differences in allele frequency between populations and low linkage disequilibrium.

IBD Discovery.

Following computational phasing with BEAGLE (27), shared IBD segments were detected by using the GERMLINE software package (28). Only non-Jewish populations from North Africa and Jewish populations were analyzed, allowing a higher-density set of 598,260 SNPs to be used.

Ancestry Deconvolution.

The Xplorigin software package was used to perform ancestry deconvolution on a subset of North African groups, by using described procedures (29, 30). Samples of North African origins were analyzed with respect to their Maghrebi, Middle Eastern, and European ancestry by using 36 non-Jewish Tunisian Berber, 48 Palestinian, and 48 Basque reference haplotypes, respectively. Data are available upon request.