Human evolution; H. sapiens all across Africa (Introduction)

by David Turell , Wednesday, January 22, 2020, 19:33 (1765 days ago) @ David Turell

From 300,000 years ago, at least four different populations:

https://www.sciencenews.org/article/ancient-kids-dna-reveals-new-insights-how-africa-wa...

"'Analyses of the west-central African children’s DNA indicate that at least three major human lineages —ancestral to either today’s central African hunter-gatherers, southern African hunter-gatherers or all other present-day people — genetically diverged from each other in rapid succession between roughly 250,000 and 200,000 years ago.

"A fourth, previously unknown human population also emerged in that time span and left a small genetic mark on modern western and eastern Africans, a team led by evolutionary geneticists Mark Lipson and David Reich...,

***

"'That genetic evidence from the long-dead kids fits a scenario in which different Homo sapiens populations emerged in different parts of Africa as early as around 300,000 years ago, followed by a mixing and mingling of populations across the continent (SN: 9/28/17).

"'A previous genetic study, led by evolutionary geneticist Pontus Skoglund of the Francis Crick Institute in London, identified a human population originating more than 200,000 years ago that was ancestral to later rainforest hunter-gatherer groups in western and central sub-Saharan Africa. The new study provides further evidence for that ancestral line: Ancient children in the new study carried a minority of ancestry from those ancient forerunners of rainforest groups.

"'Genetic data in the new study provide “the only ancient DNA record from so far west in sub-Saharan Africa,” Skoglund says.

"'Lipson’s group extracted DNA from four children buried at Shum Laka, a rock-shelter in northwestern Cameroon. Excavations there in the 1980s and 1990s yielded stone tools and other artifacts from hunter-gatherers spanning the last 30,000 years. The site also served as a cemetery for extended families. A total of 18 human skeletons, most from children, have been unearthed at Shum Laka. Some burials date to about 8,000 years ago, others to around 3,000 years ago."

Comment: H. sapiens was all over Africa as the start of our species. Did the group appear just once and spread, or were there multiple appearances? The point is not clear to me but the 300,000 year-old group was found in the Morocco area.