The Eemian out-of-Africa migration

I knew there was some West Eurasian backwash in African populations, during the last Ice Age; I further presumed there’d be Neander in that.

The article confirms the Neander component of that backwash “over roughly the past 20,000 years”. It also confirms that these were the western sort of Neander, not those Neanders (much less Denisovans) contributing to the Orient.

But I’d thought its initial mix would have come wholly from the canonical out-of-Africa 70kBC, backwashing to the Horn and Algiers over the full ice-age 13kBC. This article is talking about a full out-of-Africa around the Eemian, 130kBC – which didn’t wash back. At least, not directly at that time…

I did know of some trace of that Eemian pulse in Eurasia. Specifically: that trace is modern-human in post-Eemian western Neander corpses, recently exhumed. Now we’re seeing it back in Africa too. So it wasn’t just a one-time meetup into a population subsequently slain, like that Ice Age hybrid of Romania. Part-African hybrids were the rule in west Eurasia 120k-70kBC.

This hybrid wagons-south DNA is now expressed over a good deal of Africa; they’re talking modern Yoruba. Researchers needing a baseline for ancient DNA should use the pygmies instead.

Of interest to Africans: these Neander genes in Africa were for “bolstering the immune system and modifying sensitivity to ultraviolet radiation”. So some Eurasian plagues were roaming around Africa during that ice-age. Also (I guess) some Africans were considering a move into local forests, which the Neander DNA would have helped.

UPDATE 8/6 PM: There were earlier pulses into Europe, which didn't wash back.