Iman, a Somali model
Since I started up the African Ancestry Project one of the primary sources of interest has been from individuals whose family hail for Northeast Africa. More specifically, the Horn of Africa, Ethiopia, Eritrea, and Somalia. The problem seems to be that 23andMe's "ancestry painting" algorithm uses West African Yoruba as a reference population, and East Africans are often not well modeled as derivative of West Africans. So, for example, the Nubian individual who I've analyzed supposedly comes up to be well over 50% "European" in ancestry painting. Then again, I"m 55-60% "European" as well according that method! So we shouldn't take these judgments to heart too much. Obviously something was off, and thanks to Genome Bloggers like Dienekes Pontikos we know what the problem was: the populations of the Horn of Africa have almost no distinctive "Bantu" element to connect them with West Africans like the Yoruba. Additionally, a closer inspection shows that the "Eurasian" component present in these populations is very specific as well, almost totally derived from Arabian-like sources. When breaking apart the West Eurasian populations it is no surprise that Northern Europeans and Arabians are among the most distant pairs, even excluding recent Sub-Saharan African admixture. The HapMap Utah European American sample and the Nigerian Yoruba are very suboptimal for people with eastern African background. In contrast, African Americans are a mixture of West Africans and Northern Europeans, so the ancestry painting algorithm has nearly perfect reference populations for them. The results for African Americans may not be very detailed and rich, but they're probably pretty accurate at the level of grain which they're offering results.
