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Ancient-genome studies grapple with Africa’s past
Clutch of DNA analyses show that ancient humans moved around on the continent far more than has been appreciated.
Genome analysis of ancient people from Africa reveals a complicated migration history for the human species.
Ignored for too long by researchers, ancient humans who lived in Africa thousands of years ago are finally having their genomes studied. Two projects released results this week on the genomes of around 20 individuals, which together reveal that the history of our species on the continent is much more complex than previously thought.
Africa’s neglect until now by ancient-DNA researchers was largely a result of the continent’s scorching climate. Because heat speeds the deterioration of DNA, scientists have focused on sequencing remains from cooler European sites and Siberian permafrost. The first success in Africa came in 2015, when researchers sequenced the genome of a 4,500-year-old man from Ethiopia who was preserved in a relatively chilly mountainous cave.
But advances in removing contamination, and the discovery that a tiny inner ear bone is chock full of ancient DNA, have convinced researchers that the technology is finally ready to grapple with Africa’s past.
Stephan Schiffels, a population geneticist at the Max Planck Institute for the Science of Human History in Jena, Germany, says gaps in the knowledge of sub-Saharan African history are “embarrassing” — especially in light of how much researchers know about ancient peoples in Eurasia. This makes it all the more important to use DNA to uncover Africa's hidden history of human migration, he says.
That is what a team led by Pontus Skoglund and David Reich, population geneticists at Harvard Medical School in Boston, Massachusetts, has now done. In a talk on 3 July at the Society for Molecular Biology’s annual meeting in Austin, Texas, Skoglund said that his team had examined the genomes of 15 ancient individuals who lived as long as 6,000 years ago in eastern and southern Africa. He described a detailed analysis of 11 of them.
Highly mobile
The results showed that ancient humans moved around on the continent much more than was appreciated. The genome of a 3,000-year-old individual from Tanzania bore the ancestry not only of ancient East African hunter-gatherers but of early farmers from the Middle East. That supports past studies that documented a ‘back to Africa’ migration several thousand years ago: these migrants were closely related to early farmers from the Levant region in the Middle East.
The Tanzanian fossil was found at an archaeological site linked to animal herding, or pastoralism, and some of its genetic signatures have also been found in present-day pastoralists in southern Africa, Skoglund said. This suggests that East Africans took herding to southern Africa.
The unpublished study from Skoglund’s team revealed additional movement. The genome of a 2,000-year-old individual from southern Africa was related to those of contemporary southern African hunter-gatherers known as the San. It was also related to ancient genomes that the team had sequenced from hunter-gatherers whose remains were found in Malawi and Tanzania — but not to the DNA of the current inhabitants of East Africa.
The reason for this, Skoglund suggested, is a well-documented migration of Bantu-speaking groups from western Africa, who brought agriculture and a distinct language to eastern and southern Africa 1,000–2,000 years ago. These migrants seem to have completely replaced local hunter-gatherers. An individual who lived on Tanzania’s Zanzibar peninsula 750 years ago, after the migration, shared no ancestry with earlier hunter-gatherers from southern or East Africa.
A separate team, led by Mattias Jakobsson at Uppsala University in Sweden, found evidence for the same migrations in the genome of a boy who lived 2,000 years ago near Ballito Bay in South Africa, and in the DNA of 6 other ancient southern Africans. Their study1 was posted to the bioRxiv preprint server last month.
Proof of migrations such as the Bantu expansion have been found at archaeological sites, as well as in the DNA of contemporary Africans, says Schiffels. But it is gratifying to have direct evidence of these movements, he notes.
Early days
Ancient African genomes also have the potential to illuminate much earlier events. Jakobsson’s team used the Ballito Bay boy’s genome to infer that Homo sapiens emerged at least 260,000 years ago — much earlier than previous genetic studies have suggested. Skoglund’s team, meanwhile, used the ancient genomes it had sequenced to help uncover a possible ‘ghost population’. This, the team suggested, had diverged from the founding population of H. sapiens before any other African group, and later it contributed to the genetic make-up of some present-day West Africans.
Iain Mathieson, a population geneticist at the University of Pennsylvania in Philadelphia, hopes that ancient African DNA can explain our species’ migration out of Africa, some 50,000–100,000 years ago, by painting a genetic picture of the continents’ inhabitants around this time.
This might require DNA much older than a few thousand years — and obtaining this could require another major technical advance. Analysis of bones thought to be about 300,000 years old from Morocco, attributed to the earliest-known H. sapiens, has so far yielded no usable DNA. “It’s early days,” for ancient African genomics, says Mathieson. “It really is.”
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Yeah, this population is not "archaic" but some lost Homo-Sapiens population that separated from other H.Sapiens in Africa.
Posts: 1900 | From: NY | Registered: Sep 2014
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quote:Originally posted by BlessedbyHorus: Yeah, this population is not "archaic" but some lost Homo-Sapiens population that separated from other H.Sapiens in Africa.
This means the final shutdown on those who claimed mankind didn't originate in Africa.
Posts: 22248 | From: האם אינכם כילדי הכרית אלי בני ישראל | Registered: Nov 2010
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quote:Originally posted by BlessedbyHorus: Yeah, this population is not "archaic" but some lost Homo-Sapiens population that separated from other H.Sapiens in Africa.
This means the final shutdown on those who claimed mankind didn't originate in Africa.
Not only that but the "true negroid" West Africans carry some of the oldest African admixture.
Posts: 1900 | From: NY | Registered: Sep 2014
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quote:Originally posted by Ish Gebor: Clutch of DNA analyses show that ancient humans moved around on the continent far more than has been appreciated.
See this is the idiocy that I get annoyed with. So humankind originated in Africa and they expanded into Eurasia with populations radiating in waves from Southwest Asia to South Asia, Southeast Asia, and Australasia via a southern route while Southwest Asia to Central Asia then Europe or Siberia via a northern route. So Modern Humans became very mobile when they left Africa but in their own continent of birth, what?... Populations were more static or something?? LOL
Now that DNA testing of ancient Africans is available I'm awaiting testing of ancient populations of the Sahel and Sahara.
Posts: 26381 | From: Atlanta, Georgia, USA | Registered: Feb 2005
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quote:Originally posted by Djehuti: Now that DNA testing of ancient Africans is available I'm awaiting testing of ancient populations of the Sahel and Sahara.
If they detect ancient variety, they will claim it's due to back migration. They have cooked this plot a long time ago.
Posts: 22248 | From: האם אינכם כילדי הכרית אלי בני ישראל | Registered: Nov 2010
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quote:Originally posted by Djehuti: Now that DNA testing of ancient Africans is available I'm awaiting testing of ancient populations of the Sahel and Sahara.
If they detect ancient variety, they will claim it's due to back migration. They have cooked this plot a long time ago.
Correct. That is why they are promoting the Abusir mummies; and the Chad and Canaanite articles by Haber et al. The small samples and absence of any archaeological references to support a migration of Eurasians into Africa, in these articles, are being used to promote the back migration myth.
It is sad that the AA geneticist who are heroes of many posters on this site refuse to comment on these Eurocentric population genetics papers.
-------------------- C. A. Winters Posts: 13012 | From: Chicago | Registered: Jan 2006
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quote:Originally posted by BlessedbyHorus: Yeah, this population is not "archaic" but some lost Homo-Sapiens population that separated from other H.Sapiens in Africa.
Reminds me of Boskop Man of Southern Africa whose proportionately large braincase made all the news of a 'race of big-headed geniuses [sic] who lived in Africa' but said description meant they definitely weren't kneegrows LOL
quote:Originally posted by Ish Gebor: This means the final shutdown on those who claimed mankind didn't originate in Africa.
I think the case was "shutdown" on them a long time ago with the support of both the fossil record and DNA of modern human populations. Speaking of fossil record, didn't scientists point to the Hofmeyr Skull of Southern Africa as proof of African origins of all Eurasians??
quote:Originally posted by BlessedbyHorus: Not only that but the "true negroid" West Africans carry some of the oldest African admixture.
But how can they have "African admixture" if they are already African??! This is another point I want to bring up in regards to the whole African vs. Eurasian if 'Eurasian' originated in Africa. So we already have "pre-Eurasian" or "pre-OOA" populations living in Africa whose genetics some geneticists try to obfuscate s "Eurasian". What then are we to make of this archaic Sapiens population of West Africa??.. "Pre-West Africans" or "Pre-Negroids" LOL .
-------------------- Mahirap gisingin ang nagtutulog-tulugan. Posts: 26381 | From: Atlanta, Georgia, USA | Registered: Feb 2005
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The reason for your point 1. is exactly because of point 2.
Now that basal sapian admixture is found among West Africans, are they going to distance West Africans i.e. 'true negroes' from the rest of Africa too??! LOL
-------------------- Mahirap gisingin ang nagtutulog-tulugan. Posts: 26381 | From: Atlanta, Georgia, USA | Registered: Feb 2005
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quote:Originally posted by Djehuti: ^ Yeah tell me about it.
The reason for your point 1. is exactly because of point 2.
Now that basal sapian admixture is found among West Africans, are they going to distance West Africans i.e. 'true negroes' from the rest of Africa too??! LOL
Well, if they are trying to distance them from other Africans they fall short because West Africans carry around 70% East African admixture according to the same study. It was first Swenet or Beyoku[or both] who first put me on that.
Anyways, on another site its not that they been trying to distance West Africans from other Africans but they been trying to say since West Africans carry 30% Basel African that they are closer to chimps. LMAO!!!! Posts: 1900 | From: NY | Registered: Sep 2014
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