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Genetic Evidence for the Expansion of Arabian Tribes into the Southern Levant and North Africa

2002; Elsevier BV; Volume: 70; Issue: 6 Linguagem: Inglês

10.1086/340669

1537-6605

Almut Nebel, Ella Landau-Tasseron, Dvora Filon, Ariella Oppenheim, Marina Faerman,

Forensic Anthropology and Bioarchaeology Studies

To the Editor: In a recent publication, Bosch et al. (Bosch et al., 2001Bosch E Calafell F Comas D Oefner PJ Underhill PA Bertranpetit J High-resolution analysis of human Y-chromosome variation shows a sharp continuity and limited gene flow between northwestern Africa and the Iberian Peninsula.Am J Hum Genet. 2001; 68: 1019-1029Abstract Full Text Full Text PDF PubMed Scopus (187) Google Scholar) reported on Y-chromosome variation in populations from northwestern (NW) Africa and the Iberian peninsula. They observed a high degree of genetic homogeneity among the NW African Y chromosomes of Moroccan Arabs, Moroccan Berbers, and Saharawis, leading the authors to hypothesize that "the Arabization and Islamization of NW Africa, starting during the 7th century ad, … [were] cultural phenomena without extensive genetic replacement" (p. 1023). H71 (Eu10) was found to be the second-most-frequent haplogroup in that area. Following the hypothesis of Semino et al. (Semino et al., 2000Semino O Passarino G Oefner PJ Lin AA Arbuzova S Beckman LE De Benedictis G Francalacci P Kouvatsi A Limborska S Marcikiae M Mika A Mika B Primorac D Santachiara-Benerecetti AS Cavalli-Sforza LL Underhill PA The genetic legacy of Paleolithic Homo sapiens in extant Europeans: a Y chromosome perspective.Science. 2000; 290: 1155-1159Crossref PubMed Scopus (621) Google Scholar), the authors suggested that this haplogroup had spread out from the Middle East with the Neolithic wave of advance. Our recent findings (Nebel et al. Nebel et al., 2000Nebel A Filon D Weiss D Weale M Faerman M Oppenheim A Thomas MG High-resolution Y chromosome haplotypes in Israeli and Palestinian Arabs reveal geographic substructure and substantial overlap with haplotypes of Jews.Hum Genet. 2000; 107: 630-641Crossref PubMed Scopus (66) Google Scholar, Nebel et al., 2001Nebel A Filon D Brinkmann B Majumder PP Faerman M Oppenheim A The Y chromosome pool of Jews as part of the genetic landscape of the Middle East.Am J Hum Genet. 2001; 69: 1095-1112Abstract Full Text Full Text PDF PubMed Scopus (108) Google Scholar), however, suggest that the majority of Eu10 chromosomes in NW Africa are due to recent gene flow caused by the migration of Arabian tribes in the first millennium of the Common Era (ce). In the sample of NW Africans (Bosch et al. Bosch et al., 2001Bosch E Calafell F Comas D Oefner PJ Underhill PA Bertranpetit J High-resolution analysis of human Y-chromosome variation shows a sharp continuity and limited gene flow between northwestern Africa and the Iberian Peninsula.Am J Hum Genet. 2001; 68: 1019-1029Abstract Full Text Full Text PDF PubMed Scopus (187) Google Scholar), 16 (9.1%) of the 176 Y chromosomes studied were of Eu10 (H71 on a haplogroup 9 background). Of these 16 chromosomes, 14 formed a compact microsatellite network: 7 individuals shared a single haplotype, and the haplotypes of the other 7 were one or two mutational steps removed. This low diversity may be indicative of a recent founder effect. Where did these chromosomes come from? The highest frequency of Eu10 (30%–62.5%) has been observed so far in various Moslem Arab populations in the Middle East (Semino et al. Semino et al., 2000Semino O Passarino G Oefner PJ Lin AA Arbuzova S Beckman LE De Benedictis G Francalacci P Kouvatsi A Limborska S Marcikiae M Mika A Mika B Primorac D Santachiara-Benerecetti AS Cavalli-Sforza LL Underhill PA The genetic legacy of Paleolithic Homo sapiens in extant Europeans: a Y chromosome perspective.Science. 2000; 290: 1155-1159Crossref PubMed Scopus (621) Google Scholar; Nebel et al. Nebel et al., 2001Nebel A Filon D Brinkmann B Majumder PP Faerman M Oppenheim A The Y chromosome pool of Jews as part of the genetic landscape of the Middle East.Am J Hum Genet. 2001; 69: 1095-1112Abstract Full Text Full Text PDF PubMed Scopus (108) Google Scholar). The most frequent Eu10 microsatellite haplotype in NW Africans is identical to a modal haplotype (DYS19-14, DYS388-17, DYS390-23, DYS391-11, DYS392-11, DYS393-12) of Moslem Arabs who live in a small area in the north of Israel, the Galilee (Nebel et al. Nebel et al., 2000Nebel A Filon D Weiss D Weale M Faerman M Oppenheim A Thomas MG High-resolution Y chromosome haplotypes in Israeli and Palestinian Arabs reveal geographic substructure and substantial overlap with haplotypes of Jews.Hum Genet. 2000; 107: 630-641Crossref PubMed Scopus (66) Google Scholar). This haplotype, which is present in the Galilee at 18.5%, was termed the modal haplotype of the Galilee (MH Galilee) (Nebel et al. 2000). Notably, it is absent from two distinct non-Arab Middle Eastern populations, Jews and Muslim Kurds, both of whom have significant Eu10 frequencies—18% and 12%, respectively (Nebel et al. Nebel et al., 2001Nebel A Filon D Brinkmann B Majumder PP Faerman M Oppenheim A The Y chromosome pool of Jews as part of the genetic landscape of the Middle East.Am J Hum Genet. 2001; 69: 1095-1112Abstract Full Text Full Text PDF PubMed Scopus (108) Google Scholar). Interestingly, this modal haplotype is also the most frequent haplotype (11 [∼41%] of 27 individuals) in the population from the town of Sena, in Yemen (Thomas et al. Thomas et al., 2000Thomas MG Parfitt T Weiss DA Skorecki K Wilson JF le Roux M Bradman N Goldstein DB Y chromosomes traveling south: the Cohen modal haplotype and the origins of the Lemba—the "Black Jews of South Africa".Am J Hum Genet. 2000; 66: 674-686Abstract Full Text Full Text PDF PubMed Scopus (175) Google Scholar). Its single-step neighbor is the most common haplotype of the Yemeni Hadramaut sample (5 [∼10%] of 49 chromosomes; Thomas et al. Thomas et al., 2000Thomas MG Parfitt T Weiss DA Skorecki K Wilson JF le Roux M Bradman N Goldstein DB Y chromosomes traveling south: the Cohen modal haplotype and the origins of the Lemba—the "Black Jews of South Africa".Am J Hum Genet. 2000; 66: 674-686Abstract Full Text Full Text PDF PubMed Scopus (175) Google Scholar). The presence of this particular modal haplotype at a significant frequency in three separate geographic locales (NW Africa, the Southern Levant, and Yemen) makes independent genetic-drift events unlikely. It should be noted that the Yemeni samples (Thomas et al. Thomas et al., 2000Thomas MG Parfitt T Weiss DA Skorecki K Wilson JF le Roux M Bradman N Goldstein DB Y chromosomes traveling south: the Cohen modal haplotype and the origins of the Lemba—the "Black Jews of South Africa".Am J Hum Genet. 2000; 66: 674-686Abstract Full Text Full Text PDF PubMed Scopus (175) Google Scholar) were not typed for the binary markers (p12f2 and M172) that define Eu10. However, both Yemeni modal haplotypes are present on a haplogroup background compatible with Eu10. These haplotypes carry a DYS388 allele with a high number of repeats (i.e., 17). High repeat numbers of DYS388, ≥15, were found to occur almost exclusively on Hg9, which comprises Eu9 and Eu10. Furthermore, in a sample of a six Middle Eastern populations, chromosomes with 17 repeats are frequent (40%) in Eu10 and rare (7%) in Eu9 (Nebel et al. Nebel et al., 2001Nebel A Filon D Brinkmann B Majumder PP Faerman M Oppenheim A The Y chromosome pool of Jews as part of the genetic landscape of the Middle East.Am J Hum Genet. 2001; 69: 1095-1112Abstract Full Text Full Text PDF PubMed Scopus (108) Google Scholar). The term "Arab," as well as the presence of Arabs in the Syrian desert and the Fertile Crescent, is first seen in the Assyrian sources from the 9th century bce (Eph'al Eph`al, 1984Ephàl I The Ancient Arabs. The Magnes Press, The Hebrew University, Jerusalem1984Google Scholar). Originally referring to nomads of central and northern Arabia, the term "Arabs" later came to include the sedentary population of the south, which had its own language and culture. The term thus covers two different stocks that became linguistically and culturally unified yet retained consciousness of their discrete origins (Grohmann et al. Grohmann et al., 1960Grohmann A Caskel W Spuler B Wiet G Marcais G al-`Arab.in: Lewis B Pellat C Schacht J 2d ed. The encyclopedia of Islam. Vol 1. EJ Brill, Leiden1960: 524-533Google Scholar; Rentz Rentz, 1960Rentz G Djazirat al-`Arab.in: Lewis B Pellat C Schacht J 2d ed. The encyclopedia of Islam. Vol 1. EJ Brill, Leiden1960: 533-555Google Scholar; Caskel Caskel, 1966Caskel W Gamharat an-nasab. Vol 1. EJ Brill, Leiden1966Google Scholar, pp. 19–47; Goldziher Goldziher, 1967Goldziher I Stern SM Muslim studies. Vol 1. George Allen & Unwin, London1967Google Scholar, pp. 45–97, 164–190; Beeston Beeston, 1995Beeston AFL Saba.in: Bosworth CE van Donzel E Heinrichs WP Lecompte G 2d ed. The encyclopedia of Islam. Vol 8. EJ Brill, Leiden1995: 663-664Google Scholar; also see Peters Peters, 1999Peters FE The Arabs and Arabia on the eve of Islam. Ashgate, Brookfield, VT1999Google Scholar). Migrations of southern Arabian tribes northwards have been recorded mainly since the 3d century ce. These tribes settled in various places in central and northern Arabia, as well as in the Fertile Crescent, including areas that are now part of Israel (Dussaud Dussaud, 1955Dussaud R La penetration des Arabes en Syrie avant l`-Islam. P Geuthner, Paris1955Google Scholar; Ricci Ricci, 1984Ricci L L'expansion de l'arabie meridionale.in: Chelhod J L'Arabie du Sud. Vol 1. Maisonneuve et Larose, Paris1984: 239-248Google Scholar). The emergence of Islam in the 7th century ce furthered the unification of the Arabian tribal populations. This unified Arab-Islamic community engaged in a large movement of expansion, the Fertile Crescent and Egypt being the first areas to have been conquered. It is very difficult to trace the tribal composition of the Muslim armies, but it is known that tribes of Yemeni origin formed the bulk of those Muslim contingents that conquered Egypt in the middle of the 7th century ce. Egypt was the primary base for raids further west into the Maghrib. The conquest of North Africa was difficult and took a few decades to complete (Abun-Nasr Abun-Nasr, 1987Abun-Nasr JM A history of the Maghrib in the Islamic Period. Cambridge University Press, Cambridge1987Crossref Google Scholar). The region was militarily and administratively attached to Egypt until the beginning of the 8th century ce. Arab tribes of northern origin entered North Africa as well, both as troops and as migrants. A major wave of migration of such tribes, the Banu Hilal and Banu Sulaym, occurred during the 11th century ce (Abun-Nasr Abun-Nasr, 1987Abun-Nasr JM A history of the Maghrib in the Islamic Period. Cambridge University Press, Cambridge1987Crossref Google Scholar). Thus, the Arabs, both southern (Yemeni) and northern, added to the heterogeneous Maghribi ethnic melting pot. Little is known of the origins of the indigenous population of the Maghrib, the Berbers, except that they have always been a composite people. After the 8th century ce, a process of Arabization affected the bulk of the Berbers, while the Arab-Islamic culture and population absorbed local elements as well. Under the unifying framework of Islam, on the one hand, and as a result of the Arab settlement, on the other, a fusion took place that resulted in a new ethnocultural entity all over the Maghrib. In addition, Berber tribes sometimes claimed Arab descent in order to enhance their prestige. For example, the Berber nomadic tribe of the western Sahara, the Lamtuna, claimed descent from one of the South Arabian eponyms, Himyar. One of the chiefs of this Berber tribe, Lamtuna, is sometimes referred to as Saharawi, meaning "one of the nomads" or "one who comes from the Sahara" (Ibn al-Athir Ibn al-Athir, 1898Ibn al-Athir Annales du Maghreb et de l'Espagne. Alger, 1898Google Scholar, p. 462; Ibn Khallikan Ibn Khallikan, 1972Ibn Khallikan Wafayat al-A`yan. Vol 7. Dar al-Thaqafa, Beirut1972Google Scholar, pp. 113, 128–129; Lewicki Lewicki, 1986Lewicki T Lamtuna.in: Bosworth CE van Donzel B Lewis B Pellat C 2d ed. The encyclopedia of Islam. Vol 5. EJ Brill, Leiden1986: 652Google Scholar). In Arabic sources, however, the name Saharawi is seldom used and does not seem to refer to a specific genealogical group. In light of these historical data, it is not surprising to find, among the Berbers and contemporary Saharawis of northern Africa, Y chromosomes that may have been introduced by recurrent waves of invaders from the Arabian Peninsula. These documented historical events, together with the finding of a particular Eu10 haplotype in Yemenis, Palestinians, and NW Africans, are suggestive of a recent common origin of these chromosomes. Remarkably, the only non-Arabs in whom this haplotype has been observed to date are the Berbers (Bosch et al. Bosch et al., 2001Bosch E Calafell F Comas D Oefner PJ Underhill PA Bertranpetit J High-resolution analysis of human Y-chromosome variation shows a sharp continuity and limited gene flow between northwestern Africa and the Iberian Peninsula.Am J Hum Genet. 2001; 68: 1019-1029Abstract Full Text Full Text PDF PubMed Scopus (187) Google Scholar). It appears that the Eu10 chromosome pool in NW Africa is derived not only from early Neolithic dispersions but also from recent expansions from the Arabian peninsula. We wish to thank Dr. Elena Bosch (University of Leicester, United Kingdom) for providing haplotype information on the NW African populations. This work was supported by a research grant from the Israeli Ministry of Science, Culture and Sport.