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Modern North Africans' recent origin is outside Africa
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[QUOTE]Originally posted by Troll Patrol # Ish Gebor: [QB] [QUOTE] Tunisia has experienced a variety of human migrations that have modeled the myriad cultural groups inhabiting the area. Both Arabic and Berber-speaking populations live in Tunisia. Berbers are commonly considered as in situ descendants of peoples who settled roughly in Palaeolithic times, and posterior demographic events such as the arrival of the Neolithic, the Arab migrations, and the expulsion of the "Moors" from Spain, had a strong cultural influence. Nonetheless, the genetic structure and the population relationships of the ethnic groups living in Tunisia have been poorly assessed. In order to gain insight into the paternal genetic landscape and population structure, more than 40 Y-chromosome single nucleotide polymorphisms and 17 short tandem repeats were analyzed in five Tunisian ethnic groups (three Berber-speaking isolates, one Andalusian, and one Cosmopolitan Arab). The most common lineage was the North African haplogroup E-M81 (71%), being fixed in two Berber samples (Chenini-Douiret and Jradou), suggesting isolation and genetic drift. Differential levels of paternal gene flow from the Near East were detected in the Tunisian samples (J-M267 lineage over 30%); however, no major sub-Saharan African or European influence was found. This result contrasts with the high amount of sub-Saharan and Eurasian maternal lineages previously described in Tunisia. Overall, our results reveal a certain genetic inter-population diversity, especially among Berber groups, and sexual asymmetry, paternal lineages being mostly of autochthonous origin. In addition, Andalusians, who are supposed to be migrants from southern Spain, do not exhibit any substantial contribution of European lineages, suggesting a North African origin for this ethnic group. [/QUOTE]--David Coma et al. Am J Phys Anthropol. 2011 Oct;146(2):271-80. doi: 10.1002/ajpa.21581. Epub 2011 Aug 16. Genetic structure of Tunisian ethnic groups revealed by paternal lineages. http://www.ncbi.nlm.nih.gov/pubmed/?term=Genetic+structure+of+Tunisian+ethnic+groups+revealed+by+paternal+lineages. [QUOTE]The biological behavior of the Y chromosome, which is paternally inherited, implies that males sharing the same surname may also share a similar Y chromosome. However, socio-cultural factors, such as polyphyletism, non-paternity, adoption, or matrilineal surname transmission, may prevent the joint transmission of the surname and the Y chromosome. By genotyping 17 Y-STRs and 68 SNPs in ~2500 male samples that each carried one of the 50 selected Catalan surnames, we could determine sets of descendants of a common ancestor, the population of origin of the common ancestor, and the date when such a common ancestor lived. Haplotype diversity was positively correlated with surname frequency, that is, rarer surnames showed the strongest signals of coancestry. Introgression rates of Y chromosomes into a surname by non-paternity, adoption, and transmission of the maternal surname were estimated at 1.5-2.6% per generation, with some local variation. Average ages for the founders of the surnames were estimated at ~500 years, suggesting a delay between the origin of surnames (twelfth and thirteenth centuries) and the systematization of their paternal transmission. We have found that, in general, a foreign etymology for a surname does not often result in a non-indigenous origin of surname founders; however, bearers of some surnames with an Arabic etymology show an excess of North African haplotypes. Finally, we estimate that surname prediction from a Y-chromosome haplotype, which may have interesting forensic applications, has a ~60% sensitivity but a 17% false discovery rate.European Journal of Human Genetics advance online publication, 18 February 2015; doi:10.1038/ejhg.2015.14.[/QUOTE]--David Coma et al. Eur J Hum Genet. 2015 Feb 18. doi: 10.1038/ejhg.2015.14. [Epub ahead of print] Y-chromosome diversity in Catalan surname samples: insights into surname origin and frequency. http://www.ncbi.nlm.nih.gov/pubmed/25689924 [QUOTE]East Africa is a strategic region to study human genetic diversity due to the presence of ethnically, linguistically, and geographically diverse populations. Here, we provide new insight into the genetic history of populations living in the Sudanese region of East Africa by analysing nine ethnic groups belonging to three African linguistic families: Niger-Kordofanian, Nilo-Saharan and Afro-Asiatic. A total of 500 individuals were genotyped for 200,000 single-nucleotide polymorphisms. Principal component analysis, clustering analysis using ADMIXTURE, FST statistics, and the three-population test were used to investigate the underlying genetic structure and ancestry of the different ethno-linguistic groups. Our analyses revealed a genetic component for Sudanese Nilo-Saharan speaking groups (Darfurians and part of Nuba populations) related to Nilotes of South Sudan, but not to other Sudanese populations or other sub-Saharan populations. Populations inhabiting the North of the region showed close genetic affinities with North Africa, with a component that could be remnant of North Africans before the migrations of Arabs from Arabia. In addition, we found very low genetic distances between populations in genes important for anti-malarial and anti-bacterial host defence, suggesting similar selective pressures on these genes and stressing the importance of considering functional pathways to understand the evolutionary history of populations. [IMG]http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4446898/bin/srep09996-f1.jpg[/IMG] [i]Map of studied region in East Africa showing Sudan, South Sudan and Ethiopia, and the approximate locations of eight populations genotyped in this study. Nomadic Fulani are not shown in the map due to their wide distribution in the west, central and east of the Sudan. The inset in the top shows the locations of Sudan, South Sudan and Ethiopia in East Africa. Modified from d-maps.com. [/i] [/QUOTE]--David Coma et al. Sci Rep. 2015 May 28;5:9996. doi: 10.1038/srep09996. The genetics of East African populations: a Nilo-Saharan component in the African genetic landscape. http://www.ncbi.nlm.nih.gov/pubmed/26017457 [/QB][/QUOTE]
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