Apologies, it's not necessarily basal to Sans, but something more basal than ANA-Eurasian-ancient EA. There are a billion possibilities about what it is, it can be between Mbuti and ANA-Eurasia-ancient East African, or Mbuti and San, or just both. But whatever it is, they are from being good representatives of ancient East Africans, because they clearly have large degree of ancestry from a early branch of humanity (in respect to the main bulk of contemporary human ancestry),
Some try-hard modeling has Mota with 40.5% San-like, and the Malawian hunter gatherers at around 60%, and 31.3% in the Tanzanian hunter gatherers. The amount of Mbuti-related ancestry in Mota, and the Tanzanian and Malawian hunter gatherers hasn't been measured yet, but it will be significant at least in the southeast Africans, not sure for Mota through. So don't take these numbers as hard facts. For all we know, Somalis could be at the 50% mark of Eurasian ancestry instead of the current 40ish %.
A not so bad fit for Mota
distance%=1.5989 / distance=0.015989 Mota Dinka 59.5 South_Africa_1300BP 40.5
In fact, in the paper you yourself shared discusses how different distinctive cultural complexes and their cave paintings in East-Southeast Africa dated to different periods had differences in how they depicted (presumably) themselves, with one tradition painting generalized human figures of a linear and rather tall build, where other complexes depicted humans more like recent San hunter gatherer cave paintings, showing traits that are more strongly associated with the San. And we already know Southeast African hunter gatherers were a 3-way mix between San-related, Mbuti-related, and ancient East African, and looked quite similar to Mota, and the Pontus paper had the closely related Tanzania 1400 hunter gatherer with with 31% San-like ancestry, with the remaining portion being mostly ancient East African. Also, the archeological record already shows a distinction between San-like group, and a much more lankier group who had some sort of cultural and likely ancestral connection with mesolithic northeast Africans such as the Qadan and wavy-line cultures.
So far we have an excellent series of ancient dna from Malawi through a 6-7,000 year transect of pre-Bantu hunter gatherers, who were mostly of San-like ancestry. They look like they similar amounts of ancient East African and Mbuti-related ancestry. Their pygmy-related ancestry of these Malawian hunter gatherers, especially Hora, were probably tied to the nature of southeast African culture complexes such as the Nachikufan (which the Hora samples belonged to, the others possibly), a culture which interacted forest hunter gatherers (who were probably ancestral/related
to Pygmies) around southern Congo. The Malawian hunter gatherers were all on a tripartite cline between Pygmy and San-related, and are remarkably homogeneous despite spanning 8,000 to 2,000 years, around 6-7,000 years. The ancient Malawians hunter gatherers mostly had South African related mtdna like L0k1 and L0d1, but also more southeast African l0f and L0a1. I think they largely had pygmy related ydna, since they don't have any L1. Most likely various subclades of B-M112.
