A new preprint, Projecting ancient ancestry in modern-day Arabians and Iranians: a key role of the past exposed Arabo-Persian Gulf on human migrations, finds that Basal Eurasian (BEu) ancestry seems to peak in eastern Arabia, and among Iberomaurusian people of late Pleistocene North Africa. I think reading the preprint is important. But, to be frank, much is left unclear.

In 2014 when BEu was created as a construct to explain the greater affinities of Mesolithic European hunter-gatherers with East Eurasians than modern Europeans*, I probably would have been a little surprised that a mostly BEu individual had still not been discovered in the ancient DNA. After all, we had seen Ma’lta boy answer the question of who the mysterious “Siberians” were that left an imprint all over West Eurasia. Ma’lta was part of an ancient Paleo-Siberian group, the Ancient North Eurasians (ANE), who no longer exist in “pure” form, but contributed ancestry (or more precisely were related to groups that did so) to hunter-gatherers in Eastern Europe and the ancestors of New World populations.

No such luck with BEu. In fact, BEu as a construct is so vaguely understood that research groups can estimate that populations are 10% BEu, or 40% BEu, contingent upon various specifications in their model. In the middle 2010’s one of the scientists involved in the groups working in this space and using BEu as a construct even told me that this population may never have existed in pure form anyhow (not Iosif Lazaridis to be clear).

Basically, there is still not a lot of clarity. BEu seems to have diverged before Neanderthal admixture into the non-African lineage ~55,000 years ago. It also seems to have been subject to the long bottleneck of all non-Africans. A very plausible model that BEu occupied the southern Middle East, while non-basal Eurasians occupied the northern Middle East, seem to be the highest probability to me. The authors of this preprint argue that the Basal Eurasian ur-heimat might be in and around the Persian Gulf. I laughed when I read that because it reminds me of the early 20th century “Lost Civilization Underwater” motif. But it could be true.

I would hazard to guess dates, but I think the separation and later (early) admixture of BEu and non-BEu people in the Near East is probably strongly conditional on the paleoclimate data, which I am not fluent in.

* BEu ancestry came into Europe with Neolithic farmers, so affinities between Mesolithic hunter-gatherers and East Asians is higher than between modern Europeans and East Asians.

A new preprint, Projecting ancient ancestry in modern-day Arabians and Iranians: a key role of the past exposed Arabo-Persian Gulf on human migrations, finds that Basal Eurasian (BEu) ancestry seems
Read More

Ancient DNA