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Khoisan are the earliest to split off
Topic Started: Jun 24 2017, 12:08:57 AM (64 Views)
ren
Advanced Member
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2011 Hunter-gatherer genomic diversity suggests a southern African origin for modern humans
(Found Khoisan to be most genetically distant from Eurasians but did not conclude they were the first to branch out.)

Fine-Scale Human Population Structure in Southern Africa Reflects Ecogeographic Boundaries

Ancient genomes from southern Africa pushes modern human divergence beyond 260,000 years ago

Reconstructing prehistoric African population structure and adaptation
Abstract: The population genomic landscape of Africa prior to its transformation by expansions of farmers and pastoralists is poorly understood, partly due to poor ancient DNA preservation and partly due to the deep time scale of human population history on the continent. We assembled genome-wide data from ten sub-Saharan Africans who lived in the last 4,500 years, and show that one of the most deeply divergent present-day human lineages that is today found almost exclusively in people living in southern Africa, was in the past 2,000 years also present in populations much farther north in Malawi and the Zanzibar archipelago. These results highlight the existence of an ancient genetic cline stretched over thousands of kilometers along a south-north axis. By leveraging data from ancient African genomes without ancestry from more recent into-Africa migrations, we show that western Africans today may harbor ancestry from a lineage that separated from other modern human lineages earlier than any other, including the Khoe-San of southern Africa. Finally, we use the availability of time-stratified southern African genomes to document evidence of both selective sweeps and polygenic selection that might have conferred adaptations to desert environments.

Expanded summary*: Africa is the homeland of our species, and contains within it more human genetic diversity than the rest of the world combined. However, far less is known about the prehistory of Africa than the prehistory of other parts of the world, both because of the poor preservation of ancient DNA in Africa’s hot climate, and because of the disruptions of African population structure that occurred with the expansion of farming populations. Here we increase the amount of ancient DNA from Africa by a factor of 10 by taking advantage of recent advances for extracting DNA from ancient individuals. Using this first view of prehistoric African population structure, we provide evidence for a previously unknown hunter-gatherer population that once dominated East Africa, and the existence of an admixture gradient in which ancient East African foragers where in contact with southern African foragers as far north as Tanzania. In contrst, today such ancestry is restricted to the southern tip of Africa.. We also show evidence that West Africans today harbor substantial ancestry from a lineage that split from other modern humans before the lineage currently viewed as oldest (the Khoe-San of southern Africa). Finally, we reveal recent natural selection in the Khoe-San of southern Africa today that may have provided key adaptations to life in the open Kalahari desert, including genes affecting response to radiation and taste receptor loci. These results will provides the first view of prehistoric African population structure, and represent a first ancient genomic step into the deep past of humans in Africa.
Edited by ren, Jul 3 2017, 11:22:06 PM.
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black man
The Right Hand
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You might have to specify referring to different "branches"(?) of peripheral Africans genetically speaking, too.

Recently, I referred to a paper according to which the prehistoric northern European Motala samples appear to be genetically similar to a certain subset of Africans. That could explain why northern Europeans like the Saami tend to be relatively flat-faced but also by far more short-faced than North Asians. I.e., what people considered to "Mongoloid" admixture in northern Europeans could be due to the genetic contributions of ancient people who were phenotypically similar to certain present-day peripheral Africans.

Since you already added a separate subforum concerning this autosomal cluster, you might be interested in the potential range of topics on it... That new paper seems to suggest that it could include topics on prehistoric non-African populations as well...
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