From Eurogenes:

Ancient Egyptian Mummy Genomes Suggest an Increase of Sub-Saharan African Ancestry in Post-Roman Periods Krause et al. Egypt, located on the isthmus of Africa, is an ideal region to study historical population dynamics due to its geographic location and documented interactions with ancient civilizations in Africa, Asia, and Europe. Particularly, in the first millennium BCE Egypt endured foreign domination leading to growing numbers of foreigners living within its borders possibly contributing genetically to the local population. Here we mtDNA and nuclear DNA from mummified humans recovered from Middle Egypt that span around 1,300 years of ancient Egyptian history from the Third Intermediate to the Roman Period. Our analyses reveal that ancient Egyptians shared more Near Eastern ancestry than present-day Egyptians, who received additional Sub-Saharan admixture in more recent times. This analysis establishes ancient Egyptian mummies as a genetic source to study ancient human history and offers the perspective of deciphering Egypt’s past at a genome-wide level.

So, they are looking at DNA from mummies from a period beginning after the Late Bronze Age Collapse of around 1200 BC.

When was the camel domesticated?

One of the surprising discoveries of the late 20th Century was that the really big divide in the human race is between sub-Saharan Africans and everybody else. Back in the bad old days before political correctness, anthropologist Carleton Coon believed that Europeans and sub-Saharan Africans were more closely grouped by ancestry than were Europeans and East Asians. The mountains of Central Asia, in Coon’s theory, were the real impediment to gene flow.

But then along came the popular Out of Africa theory and it’s highly unpopular corollary: that the Sahara was the central divide in humanity.

But that raises the question of why the Sahara was such a barrier. One reason is that camels weren’t domesticated until about 3000 years ago and probably took awhile to spread out of Arabia into Africa. So the slave trade wasn’t very feasible before camels for crossing the desert.

But what about the Nile, which runs from Equatorial Africa to the Mediterranean? Shouldn’t that have led to more gene flow?

My vague impression is that the White Nile’s swamps in southern Sudan are extremely difficult. I can remember looking at a world train schedule handbook in 1980 and, south of Khartoum, it took forever to get up the Nile on a steamer due to aquatic vegetation.

But I may be all wrong about this.