Basal Eurasian discussion

[Typic]

"This introgression should be not only for Africans, but for all humans."
I didn't interpret his analysis this way.  I took it as they mated with Africans (West Africans IIRC).  His blue arrow of ~43K is pointing at the Africa branch, not the base of all Modern Humans.
That's my understanding at least.  Always willing to learn.

The autors do not claim the existance of such Ghost Archaic in all Humans. The autors concentrate their research only for some African populations.
However with their results and with other more recent results we may conclude such  Ghost Archaic contributed to all other modern Homo Sapiens.
The real question is who are the real Homo Sapiens: those from Africa, who mixed with  Ghost Archaic ?   Or  Ghost Archaic were the real Homo Sapience and they mixed with some Africans or Denisova/Neanderthals.  We may talk about 2 major components in the formation of HS..   This unknown  Ghost Archaic  is in fact one such  major component .  We may find traces of this  Ghost Archaic in Europe and Asia as well.

Isn't the "ghost archaic" ancestry negligible/relatively minor? I don't think such subtle influences meet the condition to define the deep classification applied to all people on a broad-scale level of what Homo Sapiens is or not. To my knowledge, trace-ancestry usually has a minor effect on general heritage. Sometimes, it can bear disproportional legacies but never a predominant role -- unless it is a major component.

Maybe what you mean by the "ghost" is different from my reference -- namely, the rough +2% shown in Lipson et al. (2020) attributed to the deep West African lineage/s.

Granted, 'ghost,' similar to basal Eurasian are vague terms that lack clear parameters, certainly not enough precise qualitative discernment outside macro-time scale drift perspective. That is why the Shum Laka paper separates ghost modern, which is an internal non-archaic attribution from the ghost archaic, a clear older and generally not a major component in any of the extant groups, regardless if it shows an increasing presence among the West African variation.

I would think that if we were that differentiated, it would show itself in our haplogroups. Somehow we all conveniently belong to one deep lineage tree on the paternal and maternal with no archaic distinct uniparentals in the current human diversity.