Basal Eurasians and pre-Out of Africa population structure

I don’t have time to comment in depth on the new Siberian genome paper. But I would like to mention that the text and the supplements both mention that this individual lacks the “Basal Eurasian” component which seems ubiquitous in modern West Eurasians, and was likely brought by Middle Eastern farmers. The Siberian genome seems to solidify the intuition that the non-Basal Eurasian Out of Africa populations diversified on the order of 50-60 thousand years ago. But another issue that comes to mind is that it looks like the Khosean of southern Africa might have diverged from other human groups ~200 thousand years ago. When considering the “mysterious” Basal Eurasians perhaps we should consider the possibility of a lot of population structure among anatomically modern humans within Africa. The ancestors of modern Eurasians may have been one of many African lineages, perhaps resident in a “Green Sahara” environment.