Autosomal African admixture in Yemeni populations

Another ASHG 2010 abstract. Using CEU and Maasai reference populations, the authors estimate Yemenis average about 14.8% African admixture.

Autosomal African admixture in Yemeni populations. R. L. Raaum1, A. M. Al-Meeri2, C. J. Mulligan3 1) Anthropology, Lehman College & The Graduate Center, CUNY, New York, NY; 2) Biochemistry, Faculty of Medicine, Sana'a University, Sana'a, Yemen; 3) Anthropology, University of Florida, Gainesville, FL.

Approximately 30% of mtDNA lineages in South Arabian samples are African L haplotypes, whose origin has usually been attributed to migration and assimilation of African females into the Arabian population over approximately the last 2,500 years. Few In contrast, few Y chromosome lineages of clear recent sub-Saharan African origin have been found in Southern Arabian populations. This bias in maternal and paternal lineages is in accord with historical accounts of the female bias in the Middle Eastern slave trade. In order to evaluate autosomal African ancestry, we collected high-resolution SNP genotype data from a geographically representative set of 62 Yemenis selected from a collection of 552 samples acquired in the Spring of 2007. The ancestry of chromosomal segments in the Yemeni population was estimated using a haplotype-based local ancestry estimation method, HAPMIX. The HAPMIX method is based on a two way admixture model that requires two phased reference populations; we used the HapMap Yoruba in Ibadan, Nigeria (YRI), Luhya in Webuye, Kenya (LWK), Maasai in Kinyawa, Kenya (MKK), and CEPH US residents with ancestry from northern and western Europe (CEU) samples. The three African reference populations include two Bantu-speaking groups (YRI and LWK) and one Nilotic-speaking group (MKK). We estimated local ancestry in the Yemeni sample with all three European-African reference population combinations (CEU-YRI, CEU-LWK, CEU-MKK). The correlations among African ancestry calculated using all three reference population combinations are high (r > 0.98 in all pairwise correlations). Furthermore, there is no significant difference between the average proportion of African ancestry in Yemenis calculated using either of the two Bantu-speaking reference populations: CEU-YRI (mean 0.062, sd 0.044) and CEU-LWK (mean 0.076, sd 0.049) (p=0.13, two-tailed Welch two sample t-test). However, the average African ancestry calculated using the Maasai reference population (CEU-MKK, mean 0.148, sd 0.060) is significantly greater from that calculated using either the Yoruba or Luhya reference populations (p < 0.0001 in both comparison, two-tailed Welch two sample t-test). These data suggest that the source population for the African ancestry of the Yemeni population is more similar to the contemporary Maasai population than either the Luhya or Yoruba.


Anonymous said...

Approximately 30% of mtDNA lineages in South Arabian samples are African L haplotypes, whose origin has usually been attributed to migration and assimilation of African females into the Arabian population over approximately the last 2,500 years.

A prime example of extreme patriarchy and male chauvinism gone wrong. If they do not value females then they're all equally worthless, so it does not matter if they take an African bride as long as she observes Islamic tradition and does her husband's bidding.

Wanderer said...

If it's true that the average Yemeni is 14.8% black with a, then:

The "middle two-thirds" (excluding the least-black sixth and most-black sixth) of the Yemeni population ranges from 9.0%-20.6% black. I assume the study excludes actual blacks, immigrants from Africa -- if any are included, then these percentages are of course too high for true Yemeni-Arabs.

Even assuming the 9-20% figure is a little inflated, the typical Yemeni is still in "octoroon" territory, with the darkest tenth or so of the population in "quadroon" territory!

Now consider this:
I recently learned that the actress "Maya Rudolph" is the product of an Ashkenazim father and a black woman who is probably half to two-thirds white by ancestry. Interestingly, that would make Maya Rudolph a more-Europeanized version of the typical Yemeni. [Both have about the approx. the same amount of black blood, and both have Semitic blood. Rudolph has lots of European blood too, is the difference].

Two more Ashkenazim-Black mixes are the actress-sisters "Rashida Jones" and "Kidada Jones". (The Jewish parent, a Peggy Lipton, seems to be more-Europeanized than the typical "Ostjude", from which she apparently descends... so the daughters are less in the vicinity of typical Yemeni than Miss Rudolph).

Wanderer said...

Yemeni head of state Ali Abdullah Salih has no visually-apparent black ancestry, at least not to my eye.
...Proving once again that in a population with significant black genetic infusion, those with the least black-blood will always rise to the top.

Elite Yemenis will have negligible black ancestry.

If the 14.8% figure (6 is rock-solid for true ethnic-Yemenis, then:
-- 1.1% of Yemenis have under-1% black ancestry.
-- 2.5% of Yemenis have under-3% black ancestry.
-- 5.1% of Yemenis have under-5% black ancestry.

If my speculation above that the 14.8% figure is artificially-high from some black immigrants being included, then it's very possible that closer to 5% of Yemenis have under-1% black ancestry.

The Bin-Ladens are presumably from one of these upper-strata.