https://theconversation.com/early-humans-in-africa-may-have-interbred-with-a-mysterious-extinct-species-new-research-131699
'A 2017 study of ancient DNA from southern Africa investigated 16 ancient genomes from people alive over the last 10,000 years. This showed that the history of African populations was complex. There wasn’t just a single group of humans around in Africa when they expanded out 100,000 years ago.
It’s a result that was supported earlier this year by a paper examining ancient DNA from four individuals from what is now Cameroon. Taken together, this research suggests there were geographically diverse groups in Africa well before the main expansion out of the continent. And many of these groups will have contributed to the ancestry of people alive in Africa today. [...]
The new paper provides evidence that there may also have been gene-flow into the ancestors of West Africans directly from a mysterious archaic hominin. [...]
Interestingly, they suggest that 6%-7% of the genomes of West Africans is archaic in origin. But this archaic ancestry wasn’t Neanderthal or Denisovan. Their model suggested the additional ancestry came from an archaic population for which we don’t currently have a genome.
This ghost population likely split from the ancestors of humans and Neanderthals between 360,000 and 1.02 million years ago. That was well before the gene-flow event that brought Neanderthal DNA back into West Africa around 43,000 years ago – although the value of this could be anywhere between 0 and 124,000 years ago.'
