|Some of my STR autosomal DNA genetic results from DNATribes.|
The Horn of Africa is known from ancient manuscripts to be the original home of the Berbers (Bilad al-Barbar or Land of the Berbers). My Northern European Saami-North African Berber connection (through my U5b1b1-T16192C! genetic motherline is at least 9000 years old, and given that the amount of genetic input I received from the Horn of Africa is very miniscule as compared to the North African genetic input (which is itself miniscule as compared to the pan-European genetic input), I'm guessing that the Horn of African genetic input likely occurred before anatomically modern humans (AMH) left Africa - in other words, before the differentiation of the races as we know them today.
At the time anatomically moderns humans were all in Africa, the racial type distinctions we are familiar with today (Caucasoid, Mongoloid, Negroid) did not yet exist. The different human racial types evolved through time as AMH mixed genetically with other archaic hominids particular to their regions of evolutionary development.
One cool thing I found by re-examining my African genetic ancestry - by oral family tradition, I have some Native American ancestry, but my specific Native American genetic panel came back all negative, yet evidence for it is here in this chart - my Native American genetic ancestry is seen as Mestizo in the graph, which is a mixture of Native American and European ancestry.