Ethiopian Mitochondrial DNA Heritage: Tracking Gene Flow Across and Around the Gate of Tears

Estonian Biocentre and Tartu University, Tartu, Estonia.
The American Journal of Human Genetics (Impact Factor: 10.93). 12/2004; 75(5):752-70. DOI: 10.1086/425161
Source: PubMed

ABSTRACT Approximately 10 miles separate the Horn of Africa from the Arabian Peninsula at Bab-el-Mandeb (the Gate of Tears). Both historic and archaeological evidence indicate tight cultural connections, over millennia, between these two regions. High-resolution phylogenetic analysis of 270 Ethiopian and 115 Yemeni mitochondrial DNAs was performed in a worldwide context, to explore gene flow across the Red and Arabian Seas. Nine distinct subclades, including three newly defined ones, were found to characterize entirely the variation of Ethiopian and Yemeni L3 lineages. Both Ethiopians and Yemenis contain an almost-equal proportion of Eurasian-specific M and N and African-specific lineages and therefore cluster together in a multidimensional scaling plot between Near Eastern and sub-Saharan African populations. Phylogeographic identification of potential founder haplotypes revealed that approximately one-half of haplogroup L0-L5 lineages in Yemenis have close or matching counterparts in southeastern Africans, compared with a minor share in Ethiopians. Newly defined clade L6, the most frequent haplogroup in Yemenis, showed no close matches among 3,000 African samples. These results highlight the complexity of Ethiopian and Yemeni genetic heritage and are consistent with the introduction of maternal lineages into the South Arabian gene pool from different source populations of East Africa. A high proportion of Ethiopian lineages, significantly more abundant in the northeast of that country, trace their western Eurasian origin in haplogroup N through assorted gene flow at different times and involving different source populations.

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Available from: António Brehm, Apr 29, 2014
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    • "ble S1 ) . This is reflected in a sub - stantial Eurasian autosomal component in Eastern Africa , which is also evident to some extent in Kenya ( Pagani et al . 2012 ) . Due to deep ancestry and the distribution of these lineages ( Abu - Amero et al . 2008 ; Brakez et al . 2001 ; Černý et al . 2008 ; Coudray et al . 2009 ; Fernandes et al . 2012 ; Kivisild et al . 2004 ; Olivieri et al . 2006 ; Rhouda et al . 2009 ; Richards et al . 2000 , 2003 ) , none of the West Eurasian mtDNAs found in Uganda has a likely European source , for example , resulting from the heavy European colonial involvement since the 1870s ( Maxon 2009 ) . One possibility is a Bronze - Age dispersal from the Near East accompanying"
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    ABSTRACT: The Great Lakes lie within a region of East Africa with very high human genetic diversity, home of many ethno-linguistic groups usually assumed to be the product of a small number of major dispersals. However, our knowledge of these dispersals relies primarily on the inferences of historical, linguistics and oral traditions, with attempts to match up the archaeological evidence where possible. This is an obvious area to which archaeogenetics can contribute, yet Uganda, at the heart of these developments, has not been studied for mitochondrial DNA (mtDNA) variation. Here, we compare mtDNA lineages at this putative genetic crossroads across 409 representatives of the major language groups: Bantu speakers and Eastern and Western Nilotic speakers. We show that Uganda harbours one of the highest mtDNA diversities within and between linguistic groups, with the various groups significantly differentiated from each other. Despite an inferred linguistic origin in South Sudan, the data from the two Nilotic-speaking groups point to a much more complex history, involving not only possible dispersals from Sudan and the Horn but also large-scale assimilation of autochthonous lineages within East Africa and even Uganda itself. The Eastern Nilotic group also carries signals characteristic of West-Central Africa, primarily due to Bantu influence, whereas a much stronger signal in the Western Nilotic group suggests direct West-Central African ancestry. Bantu speakers share lineages with both Nilotic groups, and also harbour East African lineages not found in Western Nilotic speakers, likely due to assimilating indigenous populations since arriving in the region ~3000 years ago.
    Human Genetics 07/2015; 134(9). DOI:10.1007/s00439-015-1583-0 · 4.82 Impact Factor
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    • "Interestingly, the flow of migrations from East Africa to the Arabian Peninsula seem to have been more recent, occurring mainly during the Arab-conducted slave trade initiated only in the seventh century AD (Richards et al., 2003; Kivisild et al., 2004). Curiously , Kivisild et al. (2004) detected a high proportion Fig. 3. Network for HVRI diversity in several regional populations. "
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    • "Our results favour the southern route hypothesis over the northern route hypothesis, and also indicate a more recent and complex colonization of Arabia than previously thought (Wildman et al., 2004; Winney et al., 2004; Fernandes, 2009). The close relationship between the Arabian population and the African population nearest to the Bab-el-Mandab Strait supports the hypothesis that this region served as an important dispersal corridor between Africa and Arabia (Wildman, 2000; Kivisild et al., 2004). "
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    Journal of Human Evolution 09/2014; 76. DOI:10.1016/j.jhevol.2014.08.003 · 3.73 Impact Factor
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