Here is the result of running ADMIXTURE for K=5 using 275K SNPs on the combined HGDP + HapMap African and West Asian populations, also including Adygei and Tuscans. The populations are in order: Luhya, Maasai, Tuscans, Yoruba, Adygei, Bedouins, Druze, Mozabites, Palestinians.
At this level of detail, Africans are divided into three clusters which can be labeled Sub-Saharan (red), East African (blue), and "Mozabite" or North African (purple). Europeans and West Asians form the green cluster, while the Arab samples have a substantial contribution of the yellow cluster.
Here are the admixture proportions:
African admixture in the two European populations is probably in the limits of statistical noise and consists of "Mozabite" (0.4%) for Tuscans and "E African" for Adygei (0.6%).
Druze, an Arab population that was religiously isolated from Arab Muslims for about a thousand years seems to have correspondingly missed most African admixture, registering 0.6% "Mozabite" and 1.1% "E African".
Non-Druze Arabs have clear traces of African admixture both in the form of "Mozabite" North African (4.5% for Palestinians, 4.9% for Bedouins), E African (6% for Palestinians and 5.7% for Bedouins) and a little Sub-Saharan (1.3% for Palestinians and 2.1% for Bedouins).
I had pointed the mainly eastern African admixture in Near Eastern Arabs a year ago in my review of HAPMIX. Clearly Maasai are a better stand-in than the Yoruba for whatever African ancestry Arabs have.
It is quite interesting to note the genetic distance (expressed in Fst) between the five inferred clusters:
We can plainly see that proximity to Eurasians increases in the order of Sub-Saharan, East African, "Mozabite". I have little doubt that Somalis and Ethiopians from East Africa would occupy an intermediate position between Maasai from Kenya and "Mozabites" in that order.
An interesting observation is that the "Arab" cluster is slightly more distant to all African clusters than the European/W Asian cluster is. This might seem perplexing as geography might dictate that it should be closer to the African clusters.
However, this is not very surprising to me, as there was gene flow between West Asia and Europe and Africa in old times, evidenced by such things as the presence of Eurasian Y-haplogroup R-V88 in Africa and African haplogroup E1b in Europe and West Asia.
The original Arab ancestors, were probably haplogroup J1e-bearing Semites exploiting arid environments of West Asia. Present-day Levantine Arabs (especially Bedouins, in the available samples) maintain a strong signal of this component of their ancestry, admixed, however, principally with the original Tuscan- and Adygei- like West Asians, and secondarily with E and N Africans.
Revisiting GenomesUnzipped "Ashkenazi Jewish" admixture
There were two individuals in my recent post who showed some evidence of "Ashkenazi Jewish" admixture (DBV001: 100% and VXP001: 32%). I list in the comments of that post some possible explanatios for why VXP001 (who has no knowledge of Jewish ancestry) might get such a result. Naturally, using 275K SNPs is better than the 192 of EURO-DNA-CALC, so I did a separate run that included these two individuals.
The results are:
DBV001: 85.1% European/W Asian, 10.5% "Arab", 0.5% "E African", and 3.8% "Mozabite". This is entirely consistent with full known Jewish ancestry. The closest population to the Middle Eastern component of Jews are presumably the Druze, who have about 16.9% of the "Arab" (which should probably be relabeled "Semitic") cluster. Ashkenazi Jews are known to be intermediate between Levantine and European populations, and DBV001's result is entirely consistent with this.
As I've mentioned before, the exact percentage of Middle Eastern ancestry in modern European Jews is difficult to estimate, as this would depend on determining the exact percentage of "European/W Asian" and "Semitic" components was present in their gene pool before they settled in Europe. If, for example, they were 100% in the "Semitic" cluster, then DBV001 would be about 10% of Middle Eastern ancestry, but if they were like modern Druze, then this percentage would be 100*10.5/16.9 = 62.1%. The truth is probably somewhere in between.
VXP001: A shorter story, as VXP001 comes out 100% "European/W Asian". Thus, I am inclined to believe that VXP001's AJ score is either due to the small number of markers, or to a European-origin component in the composite Ashkenazi Jewish gene pool that he happens to share.
UPDATE (Oct 23): A much more detailed analysis of Genomes Unzipped individuals.