Token
01-14-2021, 01:02 PM
It seems i missed this paper. Summary of the conclusions:
It looks like there was a large back-migration event in the Late Middle Paleolithic which replaced a large part of the population of Sub-Saharan Africa.
No evidence for bidirectional geneflow after the out-of-Africa event.
The Eurasian back-migration seems to predate admixture events with archaic hominids - no evidence of Neanderthal and Denisovan in modern-day Africans.
The estimates were 0.35±0.04 for Niger-Kordofanians, and 0.41±0.03 for Nilo-Saharans when using modern-day Eurasians as reference. The authors tells us that these figures may be even higher given that the Neanderthal admixture in the references used may deflate the real percentages.
South African hunter-gatherers such as the Khoe-san got substantially less Eurasian admixture, more or less half the amount of admixture seen in Yoruba and Nilo-Saharans.
Mbuti-Biaka are intermediate between Khoe-san and West Africans in terms of Eurasian admixture.
https://www.biorxiv.org/content/10.1101/2020.06.01.127555v1.full.pdf
Abstract: Genetic diversity across human populations has been shaped by demographic history, making it possible
to infer past demographic events from extant genomes. However, demographic inference in the ancient
past is dicult, particularly around the out-of-Africa event in the Late Middle Paleolithic, a period of
profound importance to our species’ history. Here we present SMCSMC, a Bayesian method for inference of
time-varying population sizes and directional migration rates under the coalescent-with-recombination
model, to study ancient demographic events. We find evidence for substantial migration from the
ancestors of present-day Eurasians into African groups between 40 and 70 thousand years ago, predating
the divergence of Eastern and Western Eurasian lineages. This event accounts for previously unexplained
genetic diversity in African populations, and supports the existence of novel population substructure
in the Late Middle Paleolithic. Our results indicate that our species’ demographic history around the
out-of-Africa event is more complex than previously appreciated.
It looks like there was a large back-migration event in the Late Middle Paleolithic which replaced a large part of the population of Sub-Saharan Africa.
No evidence for bidirectional geneflow after the out-of-Africa event.
The Eurasian back-migration seems to predate admixture events with archaic hominids - no evidence of Neanderthal and Denisovan in modern-day Africans.
The estimates were 0.35±0.04 for Niger-Kordofanians, and 0.41±0.03 for Nilo-Saharans when using modern-day Eurasians as reference. The authors tells us that these figures may be even higher given that the Neanderthal admixture in the references used may deflate the real percentages.
South African hunter-gatherers such as the Khoe-san got substantially less Eurasian admixture, more or less half the amount of admixture seen in Yoruba and Nilo-Saharans.
Mbuti-Biaka are intermediate between Khoe-san and West Africans in terms of Eurasian admixture.
https://www.biorxiv.org/content/10.1101/2020.06.01.127555v1.full.pdf
Abstract: Genetic diversity across human populations has been shaped by demographic history, making it possible
to infer past demographic events from extant genomes. However, demographic inference in the ancient
past is dicult, particularly around the out-of-Africa event in the Late Middle Paleolithic, a period of
profound importance to our species’ history. Here we present SMCSMC, a Bayesian method for inference of
time-varying population sizes and directional migration rates under the coalescent-with-recombination
model, to study ancient demographic events. We find evidence for substantial migration from the
ancestors of present-day Eurasians into African groups between 40 and 70 thousand years ago, predating
the divergence of Eastern and Western Eurasian lineages. This event accounts for previously unexplained
genetic diversity in African populations, and supports the existence of novel population substructure
in the Late Middle Paleolithic. Our results indicate that our species’ demographic history around the
out-of-Africa event is more complex than previously appreciated.