Rare African sequences illuminate history of early humans in Africa

[Angela]

See:

"Rare genetic sequences illuminate early humans' history in Africa"
https://www.nature.com/articles/d41586-018-07164-9

I think we can expect the actual papers shortly

"These preliminary results suggest that more than 40,000 years ago, two of the groups — the San and the Baka Pygmy — were roughly twice the size of other ethnic groups present at the time, and that the San and Baka overlapped in central-eastern or southern Africa. "

"Statistical models of the data indicate that the Hadza and the Sandawe people of Tanzania shared an ancestor in the past 30,000 years.The findings also suggest that there was intermingling during that period between the Hadza, the San in southern Africa and the Baka in central Africa, all of whom were traditionally hunter-gatherers. “I think we are seeing an ancient common ancestry between the major hunter-gatherer groups in Africa,” Tishkoff says.
Some of the findings align with signals of mixed Hadza and San ancestry in DNA extracted from 2,500- to 8,100-year-old human remains1, says Pontus Skoglund, a palaeogeneticist at the Francis Crick Institute in London. “I had been thinking about an interconnected hunter-gatherer population stretching from present-day Tanzania to South Africa.”"

 

[bicicleur 2]

if I understand well, this study is based on extant DNA, not anciant DNA
I doubt this allows to make conclusions about what happened 30-40 ka
but I'm curious

 

[Megalophias]

Good to see some autosomal evidence of this - since all San Y haplogroups were shared with East or Central Africans within the last 30-60 000 years there had to be some admixture. I wonder what this means for estimates of 200 000 years of divergence or whatever - will that get even older? Is there some archaic ancestry involved?

Unnecessary detail follows:

A1b1a1-M14 - San A-M6 and Baka Pygmy A-M10424, TMRCA ~30 000 years from Hallast et al (2014) data, also seen in Karmin et al (2015). 3/32 Gbaya (non-Pygmies) from Central African Republic had A-M14* with a similar STR haplotype to Baka's in Naidoo's thesis (2014)

A1b1b2-M144/YP4735 - San A-M51 and widespread A-M13 - YF TMRCA ~54 000 years

B2b1-M192 - various branches - YF TMRCA 42-49 000 years, but shared subclades are more recent
B2b1a1'2-M8495/M8508 - 38-45 000 years - there is a minor Khoisan branch under here somewhere
B2b1a1-M8357 - 32-39 000 years - YF Arabians and Baka, Biaka, Bakola, Mbenzele, and Mbuti Pygmies
B2b1a2-M7583 - YF has only Kuwaiti B-Y82361 but this branch also contains Hadza, Sandawe, and Baka
B2b1b-V3853/M7125/M7104 - 35-41 000 years - includes Sandawe as well as the below groups
B2b1b1-Y25096 - 26-32 000 years - YF B-P6 with 2 Namibian San (this is common among Khoisan) and B-Y34339 with 2 Arabs
B2b1b2-Y34326 - 25-32 000 years - contains a Mbuti and a Saudi - also Hadza B-M8645 is on this branch