Too small of a sample size make much of it. This is the second study that reports on West Africa being more Bushman than Bantu. I can't find the raw data. Just one A00 haplogroup.
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Interesting information, but are Africans in these respective fields apart of these institutions as contributing members? I get knowledge is for everybody but this makes no sense if African people aren't apart of writing others folks history.
This study was the product of collaboration among geneticists, archaeologists, biological anthropologists and museum curators based in North America (including Harvard Medical School and the Université de Montréal); Europe (Royal Belgian Museum of Natural Sciences, Royal Museum for Central Africa, Université Libre de Bruxelles and Saint Louis University’s Madrid campus); Cameroon (University of Yaoundé, University of Buea); and China (Duke Kunshan University). Posts: 1123 | From: New York | Registered: Feb 2016
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Too small of a sample size make much of it. This is the second study that reports on West Africa being more Bushman than Bantu. I can't find the raw data. Just one A00 haplogroup.
They don't care about sample size. They still go on to make broad and sweeping generalizations based on a sample of four individuals thousands of years apart. John Hawks went in on them on Twitter: John HawksPosts: 288 | From: Asia | Registered: Mar 2016
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Ancient West African foragers in the context of African population history Mark Lipson, Isabelle Ribot, […]David Reich Nature (2020)
Abstract Our knowledge of ancient human population structure in sub-Saharan Africa, particularly prior to the advent of food production, remains limited. Here we report genome-wide DNA data from four children—two of whom were buried approximately 8,000 years ago and two 3,000 years ago—from Shum Laka (Cameroon), one of the earliest known archaeological sites within the probable homeland of the Bantu language group1,2,3,4,5,6,7,8,9,10,11. One individual carried the deeply divergent Y chromosome haplogroup A00, which today is found almost exclusively in the same region12,13. However, the genome-wide ancestry profiles of all four individuals are most similar to those of present-day hunter-gatherers from western Central Africa, which implies that populations in western Cameroon today—as well as speakers of Bantu languages from across the continent—are not descended substantially from the population represented by these four people. We infer an Africa-wide phylogeny that features widespread admixture and three prominent radiations, including one that gave rise to at least four major lineages deep in the history of modern humans.
Too small of a sample size make much of it. This is the second study that reports on West Africa being more Bushman than Bantu. I can't find the raw data. Just one A00 haplogroup.
from link:
Saint Louis University
Nature Study: First Ancient DNA from West Africa Illuminates the Deep Human Past 01/22/2020
A team of international researchers, which includes a Saint Louis University Madrid anthropologist, dug deep to find some of the oldest African DNA on record, in a new study published in Nature.
“Our analysis indicates the existence of at least four major deep human lineages that contributed to people living today, and which diverged from each other between about 250,000 and 200,000 years ago,” said David Reich, Ph.D., of Harvard Medical School, senior author of the study.
These lineages are ancestral to present-day central African hunter-gatherers, southern African hunter-gatherers, and all other modern humans, with a fourth lineage being a previously unknown ‘ghost population’ that contributed a small amount of ancestry to both western and eastern Africans.
“This quadruple radiation—including the position of a deeply-splitting ‘ghost’ modern human lineage—had not been identified before from DNA,” Reich said.
Key Take-Aways
⬤The study examines DNA from four people buried in the Shum Laka rockshelter in Cameroon, about 8,000 years ago and 3,000 years ago, at the transition from the Stone to Iron Ages. This study reports the first ancient DNA recovered from West or Central Africa, and includes some of the oldest DNA recovered from the African tropics.
⬤This part of west-central Africa – the ‘Grassfields’ region of Cameroon – has been identified as the probable cradle of Bantu languages, the most widespread and diverse group of languages in Africa today. For decades, linguists, archaeologists, and geneticists have investigated the origin of Bantu languages and their spread.
⬤ None of the sampled individuals from Shum Laka are closely related to most present-day Bantu-speakers. Instead, they were part of a separate population that lived in the region for at least five millennia, and was later almost completely replaced by very different populations whose descendants comprise most people living in Cameroon today.
⬤ The Shum Laka individuals harbored about two-thirds of their ancestry from a previously unknown lineage distantly related to present-day West Africans and about one-third of their ancestry from a lineage related to present-day central African hunter-gatherers. This finding reveals previously unknown genetic diversity prior to the spread of food production.
⬤ Analysis of whole-genome ancient DNA data from these individuals provided insights into the relationships among several early-branching African human lineages. Results suggest that lineages leading to today’s central African hunter-gatherers, southern African hunter-gatherers, and all other modern humans diverged in close succession about 250,000-200,000 years ago.
⬤ Another set of genetic divergences was identified dating to about 80,000-60,000 years ago, including the lineage leading to all present-day non-Africans.
⬤ These findings strengthen arguments recently made by archaeologists and geneticists that human origins in Africa may have involved deeply divergent, geographically separated populations.
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John Hawks' remarks, twitter
More The past is complicated. So is the present. Reading in @nature on the Shum Laka aDNA: Archaeological samples in a colonial museum used to argue that today's population of Cameroon are not descended from past peoples in the area.
The authors emphasize discontinuity in their overall interpretation, yet data show substantial evidence of some population continuity both regionally and locally. Small fractions of ancestry from "ghost" groups are highlighted, but small fractions from modern groups downplayed.
I'm fascinated by the concept of a tree seeming to show groups a part of a pure history of divergence, yet each group shows most of its heritage came from elsewhere in the tree. Shum Laka appears as a pure representative of an ancient group, with 64% from some other group.
More The obvious question is why would you illustrate the 36% as the main pattern determining the place in the tree, instead of the 64%? In addition to the old unanswered question: What are these "basal" ancestry components if not a statistical artifact?
My thought today is that the contemporary and historical political complexity, and the unanswered questions about the models, are now the interesting and challenging scientific issues. Deeply redacted SNP samples of ancient genomes are not getting at these questions.
Also, why the heck is it "ghost modern" and not "basal modern". And don't these geneticists know that "basal" is a no-no term in phylogenetics?
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Razib Khan remark:
Look a the supplements and notice all the admixture graphs. There are lots of potential fits to the data, and more data will come in. The paper is clear to not put too much faith in one set of weights for gene flows, and different graphs might explain the patterns in the data. Additionally, a highly dense African landscape of hominins might exhibit lots of continuous gene flow and isolation by distance. There’s a lot more to learn. Nothing is being closed in this case.
quote:Originally posted by Thereal: Interesting information, but are African in these respective fields apart of these institutions as contributing members? I get knowledge is for everybody but this makes no sense if African people aren't apart of writing others people history.
This study was the product of collaboration among geneticists, archaeologists, biological anthropologists and museum curators based in North America (including Harvard Medical School and the Université de Montréal); Europe (Royal Belgian Museum of Natural Sciences, Royal Museum for Central Africa, Université Libre de Bruxelles and Saint Louis University’s Madrid campus); Cameroon (University of Yaoundé, University of Buea); and China (Duke Kunshan University).
True, and it's very important to acknowledge this fact.
Too small of a sample size make much of it. This is the second study that reports on West Africa being more Bushman than Bantu. I can't find the raw data. Just one A00 haplogroup.
If that is the case, we are getting somewhere. Very close...
quote:Cruciani et al18 found this paragroup (at that time defined as haplogroup 117, orR-M173 *( xSRY10831,M18,M73,M269)) to be present at high frequencies (up to 95%) in populations from northern Cameroon. The sameparagroup was only rarely observed in other sub-Saharan African regions, and not observed at all in western Eurasia.18
~Fulvio Cruciani European Journal of Human Genetics advance online publication, 6 January 2010; doi:10.1038/ejhg.2009.231 Human Y chromosome haplogroup R-V88: a paternalgenetic record of early mid Holocene trans-Saharanconnections and the spread of Chadic languages
And this remains a problem none of them touches. They all dance around this one:
quote:"deepest branching separates A1b from a monophyletic clade whose members (A1a, A2, A3, B, C, and R) all share seven mutually reinforcing derived mutations (five transitions and two transversions, all at non-CpG sites)."
~Fulvio Cruciani A Revised Root for the Human Y Chromosomal Phylogenetic Tree: The Origin of Patrilineal Diversity in Africa
In this video we have discussed the CpG islands which are found in DNA strands.C refers to Cytosine while as G refers to Guanine and the P is Phosphate between them.
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