Fine-Scale Human Population Structure in Southern Africa Reflects Ecogeographic Boundaries Caitlin Uren, Minju Kim, Alicia R. Martin, Dean Bobo, Christopher R. Gignoux, Paul D. van Helden, Marlo Möller, Eileen G. Hoal, Brenna M. Henn GENETICS September 1, 2016 vol. 204 no. 1 303-314; DOI: 10.1534/genetics.116.187369
Abstract
Recent genetic studies have established that the KhoeSan populations of southern Africa are distinct from all other African populations and have remained largely isolated during human prehistory until ∼2000 years ago. Dozens of different KhoeSan groups exist, belonging to three different language families, but very little is known about their population history. We examine new genome-wide polymorphism data and whole mitochondrial genomes for >100 South Africans from the ≠Khomani San and Nama populations of the Northern Cape, analyzed in conjunction with 19 additional southern African populations. Our analyses reveal fine-scale population structure in and around the Kalahari Desert. Surprisingly, this structure does not always correspond to linguistic or subsistence categories as previously suggested, but rather reflects the role of geographic barriers and the ecology of the greater Kalahari Basin. Regardless of subsistence strategy, the indigenous Khoe-speaking Nama pastoralists and the N|u-speaking ≠Khomani (formerly hunter-gatherers) share ancestry with other Khoe-speaking forager populations that form a rim around the Kalahari Desert. We reconstruct earlier migration patterns and estimate that the southern Kalahari populations were among the last to experience gene flow from Bantu speakers, ∼14 generations ago. We conclude that local adoption of pastoralism, at least by the Nama, appears to have been primarily a cultural process with limited genetic impact from eastern Africa.
Posts: 42934 | From: , | Registered: Jan 2010
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^ So no Eurasian Caucasoid admixture as was previously thought?? LOLPosts: 26262 | From: Atlanta, Georgia, USA | Registered: Feb 2005
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The article does mention recent admixture with European Caucasoids>
quote:
Our results are consistent with Pickrell et al. (2012) who found that the southern Kalahari Taa speakers were the last to interact with the expanding Bantu speakers ∼10–15 generations ago. Subsequently, this event was followed by admixture with Europeans between 6 and 7 generations ago (∼233–263 years ago), after the arrival of the Dutch in the Cape and the resulting migrations of “trekboers” (nomadic pastoralists of Dutch, French, and German descent) from the Cape into the South African interior. Lastly, we find a recent pulse of primarily KhoeSan ancestry 4–5 generations ago (∼173–203 years ago). This event could be explained by gene flow into the ≠Khomani from another KhoeSan group, potentially as groups shifted local ranges in response to the expansion of European farmers in the Northern Cape, or other population movements in southern Namibia or Botswana.
Quote: We conclude that local adoption of pastoralism, at least by the Nama, appears to have been primarily a cultural process with limited genetic impact from eastern Africa.
-------------------- Without data you are just another person with an opinion - Deming Posts: 12143 | From: When you have eliminated the impossible, whatever remains, however improbable | Registered: Jun 2007
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quote:Originally posted by xyyman: The Bantus expansion never occured
Quote: We conclude that local adoption of pastoralism, at least by the Nama, appears to have been primarily a cultural process with limited genetic impact from eastern Africa.
The bantu expansion was FROM West Africa to south, central and east Africa
So therefore you highlighting "limited genetic impact from eastern Africa." means you don't know this.
The Khosians are mixed with bantu speakers.
They had to come from somewhere
I think you just like saying " The Bantus expansion never occurred" because it sounds like a conspiracy theory "man never landed on the moon"
Posts: 42934 | From: , | Registered: Jan 2010
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You are hilarious. Why do I need to dumb it down. Part of the Bantu Expansion Theory is FROM West Africa to South East Africa to Southern Africa. Hence the highlighted section. There was no movement from East to South according to this paper . ...thus Bantus DID NOT enter South Africa from the East .which negates that portion of the Bantu Theory . Smh!
-------------------- Without data you are just another person with an opinion - Deming Posts: 12143 | From: When you have eliminated the impossible, whatever remains, however improbable | Registered: Jun 2007
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I haven't read the entire study as yet . .......
-------------------- Without data you are just another person with an opinion - Deming Posts: 12143 | From: When you have eliminated the impossible, whatever remains, however improbable | Registered: Jun 2007
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Part of the Bantu Expansion Theory is FROM West Africa to South East Africa to Southern Africa. Hence the highlighted section.
[QUOTE]Originally posted by the lioness,: [QUOTE]Originally posted by xyyman: limited genetic impact from eastern Africa.
^^^ here's the highlighted section that means if there was limited genetic impact from eastern Africa that instead the impact was from West Africa to South East Africa to Southern Africa, ie the bantu migration
Posts: 42934 | From: , | Registered: Jan 2010
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quote:Originally posted by the lioness,: The article does mention recent admixture with European Caucasoids>
quote:
Our results are consistent with Pickrell et al. (2012) who found that the southern Kalahari Taa speakers were the last to interact with the expanding Bantu speakers ∼10–15 generations ago. Subsequently, this event was followed by admixture with Europeans between 6 and 7 generations ago (∼233–263 years ago), after the arrival of the Dutch in the Cape and the resulting migrations of “trekboers” (nomadic pastoralists of Dutch, French, and German descent) from the Cape into the South African interior. Lastly, we find a recent pulse of primarily KhoeSan ancestry 4–5 generations ago (∼173–203 years ago). This event could be explained by gene flow into the ≠Khomani from another KhoeSan group, potentially as groups shifted local ranges in response to the expansion of European farmers in the Northern Cape, or other population movements in southern Namibia or Botswana.
"Subsequently, this event was followed by admixture with Europeans between 6 and 7 generations ago (∼233–263 years ago), after the arrival of the Dutch in the Cape and the resulting migrations of “trekboers” (nomadic pastoralists of Dutch, French, and German descent) from the Cape into the South African interior. "
You obviously did not comprehend Djehuti's comment and observation.
Posts: 22235 | From: האם אינכם כילדי הכרית אלי בני ישראל | Registered: Nov 2010
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Speaking of which, this thread reminds me to write something I should have written long ago in this forum and is very overdue. First of all, due to the Eurocentrics, whenever Eurasians in general are discussed and especially the first Eurasians of OOA there is always this conception that they are “Caucasoid” in morphology or somehow have a close or direct tie to today’s western Eurasians especially Southwest Asians who exhibit said “Caucasoid” morphology as well as Europeans. This focus on West Eurasians-Europeans-“caucasoids” ignores those Eurasians who carry deepest OOA clades but are found in eastern Eurasia, Australasia, and parts of the Pacific. This focus also ignores populations in India and even parts of Arabia who don’t exactly exhibit the “Caucasoid” morphology. Secondly and more direct to the opening topic, the Khoisan peoples of southern Africa have been noted by genetic experts to carry among the oldest clades in the world that date prior to OOA and have often been held by many laypeople erroneously as examples of an original AMH phenotype or at least a pre-OOA phenotype. The phenotype of the Khoisan is very interesting because back in the very beginnings of Western anthropology in the 18th century and as late as the early 19th century there was speculation of a genetic tie between the Khoisan and East Asian so-called “Mongoloids” for obvious reason of typological similarities in craniofacial morphology. While the distance in geographic ranges as well as other significant differences in overall skeletal morphology and even early genetic evidence via blood and serology has debunked any “Mongoloid” claims for the Khoisan, the same significant differences between indigenous North and Horn Africans and indigenous Europeans and light-skinned SW Asians haven’t stopped Western anthropologists from claiming such Africans as “Caucasians”! This is the ultimate hypocrisy that many people both in academia and outside have been pointing out for decades. Scholars from Franz Boas to Cheikh Diop have noted the glaring double-standards and hypocrisy in attempts to claim populations as “Caucasoid” or basically white-wash African populations, and while there is indeed close geographic proximity between North Africa and the Horn Africa to Europe and SW Asia, the differences in overall skeletal morphology or blood and serology were not taken into account. And even though it is confirmed that both SW Asians and Europeans did receive admixture from Africans during the Neolithic accounting for some genetic similarities and overlap, many Eurocentrics today tend to ignore that this was admixture between disparate populations. Basically, what I’m trying to say is that if “Caucasoid” is nothing more than a typological classification based on superficial features alone just as “Mongoloid”, and if North Africans and Horn Africans can be labeled as “Afro-Caucasoids”, then why can’t Khoisan people be labeled as Afro-Mongoloids??!
We know from anthropologists like Susan Anton, Sonia Zakrzewski, and Shomarka Keita that indigenous North Africans, especially northeast Africans like the ancient Egyptians are physically continuous with so-called ‘Sub-Saharan’ Africans. Craniofacially the only thing “Caucasoid” are certain facial traits like orthognathy, leptoprosopy, and leptorrhiny, as well as certain dental features such as smaller teeth. As we’re all aware, post-cranially the skeletal bodies display tropical to supra-tropical limb proportions and even same skeletal shape as other Sub-Saharans. The only soft tissue feature deemed “Caucasoid” I can think of is hair form that is loose i.e. loose curled, wavy, or straight hair. My only argument is that Khoisan have equally as many traits in common with East Asians if not more so than North/East Africans have in common with Europeans! Cranially, the Khoisan are typically mesoprosopic though leptoprosopy is not unusual, their jaws are orthognathous with minor alveolar prognathism and some occurrence of moderate chin projection, they typically have spade shaped nasal openings, roundish orbits, and although their cheekbones do not project like ‘mongoloids’ but are receding, their prominent size in conjunction with the configuration of the rest of the face may give the impression of an east Asian. All the other skeletal traits they share with East Asians is due to neoteny, such as large, globular crania with smooth sutures, high prominent forehead, smooth brow ridges, etc. Although neoteny occurs in other African populations and is also considered a ‘negroid’ trait, it is pronounced in Khoisan as it is in so-called ‘mongoloids’. Interestingly, the incisors of Khoisan are shovel shaped like many East Asians. In soft tissue features Khoisan also share a number of striking features with Asians such as skin with thick cuticles and high amounts of keratin (yellow pigment), fatty deposits lining eyes sockets, and small eyes with epicanthic eyelid folds. Epicanthic folds occur in varying frequencies throughout African populations including Nile Valley populations, but they have their highest frequency in Khoisan. Another interesting fact is that even the ‘Mongolian spot’ occurs among some Khoisan children though the highest frequency occurs in in children of East African populations while it is near absent in West Africans. By the way, despite the name the ‘Mongolian spot’ also occurs in Australasian aborigines in the Pacific as well.
The presumed ancestors of the Khoisan are the so-called Boskop people (30-10 kya) noted for their very large skulls and child-like features that they were at first mistaken for a new hominid species but were then realized to be a variant of early Sub-Saharans related to the likes of Nazlet Khater. However, the discovery of the even earlier Hofmeyr skull (37-20 kya) in the Cape area whose features resembled contemporary Upper Paleolithic Eurasians seems to suggest more complex origins for the Khoisan than simply the Boskop. Certain phenotypic traits like ‘Mongolian sacral spotting’ as well as recent genetic findings connecting Khoisan to Mota seems to me a link between Khoisan ancestors and pre-OOA if not the alleged ‘basal Eurasians’. Either way, I find it blatantly biased to impose Eurasian phenotypic monikers of “Caucasoid” onto Africans but never “Mongoloid”.
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