Probing the deep genetic structure of Africa | Max-Planck-Gesellschaft
Creationist dupes believe that all human life on Earth was reduced to a small band of 8 related individuals who survived a global genocidal flood and then got off a boat in Turkey and repopulated Earth from there.
Their problem is that this ludicrously implausible tale gives us a testable hypothesis - that an analysis of human genetics should show this bottle neck and the distribution of humans from that geographical point. We would also expect the greatest diversity to be found around the area of modern Turkey.
And of course, this hypothesis is easily and repeatedly falsified, which normally spells the death of any scientific hypothesis.
The scientific explanation for human origins is that modern Homo sapiens evolved in Africa and spread to the rest of the world from there, preceded, probably by archaic hominids such as H. erectus. A hypothesis stemming from this theory is that the greatest genetic diversity is to be found in Africa, because humans have been evolving there for longer than anywhere else. A recent refutation of it was found in an analysis of the genome of ancient people in the Angola/Namib region of Africa, which also validates the 'out of Africa' theory of human origins.
The work was done by a research team from the University of Bern in Switzerland, the University of Porto in Portugal and the Max Planck Institute for Evolutionary Anthropology in Germany. The Maz Planck Institute News release explains it:
DNA research from human populations thought to be uncontactable or extinct helps probe the deep genetic structure of AfricaThat’s the problem with having a counter-factual superstition as the basis of a cult - it is constantly being refuted by real-world evidence - so the strategies needed to maintain the cultic beliefs become more and more ridiculous and the members look more and more like scientifically illiterate, gullible fools.
Using ancestry decomposition techniques an international research team from the University of Bern in Switzerland, the University of Porto in Portugal and the Max Planck Institute for Evolutionary Anthropology in Germany has revealed a deeply divergent ancestry among admixed populations from the Angolan Namib desert. This unique genetic heritage brings the researchers closer to understanding the distribution of genetic variation in the broader region of southern Africa before the spread of food production.
Africa is the birthplace of modern humans and the continent with the highest level of genetic diversity. While ancient DNA studies are revealing some aspects of the genetic structure of Africa before the spread of food production, issues concerning DNA preservation have limited the insights from ancient DNA. Hoping to find clues in modern populations, researchers from a Portuguese-Angolan TwinLab ventured into the Angolan Namib desert – a remote, multi-ethnic region where different traditions met. “We were able to locate groups which were thought to have disappeared more than 50 years ago”, states Jorge Rocha, a population geneticist from Centro de Investigação em Biodiversidade e Recursos Genéticos (CIBIO, University of Porto) who led the fieldwork, together with Angolan anthropologists Samuel and Teresa Aço from the Centro de Estudos do Deserto (CEDO).
Among the communities the team encountered are the Kwepe, a pastoral group who used to speak a language known as Kwadi. “Kwadi was a click-language that shared a common ancestor with the Khoe languages spoken by foragers and herders across southern Africa,” explains Anne-Maria Fehn, a linguist from CIBIO who participated in the fieldwork and was able to interview what may well be the last two speakers of Kwadi. “Khoe-Kwadi languages have been linked to a prehistoric migration of eastern African pastoralists”, adds Rocha, whose research focuses on southern African population history. In addition, the team contacted Bantu-speaking groups that are part of the dominant pastoral tradition of southwest Africa, as well as marginalized groups whose origins have been associated with a foraging tradition, distinct from that of the neighboring Kalahari peoples, and whose original language was supposedly lost.
Modern DNA research can complement ancient DNA studies
The team‘s new study shows that the inhabitants of the Angolan Namib are quite divergent from other modern populations but also highly structured among themselves.Previous studies revealed that foragers from the Kalahari desert descend from an ancestral population who was the first to split from all other extant humans. Our results consistently place the newly identified ancestry within the same ancestral lineage but suggest that the Namib-related ancestry diverged from all other southern African ancestries, followed by a split of northern and southern Kalahari ancestries.
Mark Stoneking, co-author
Department of Evolutionary Genetics
Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.
The team demonstrated that besides the high impact of genetic drift, which contributed to differences among neighboring groups of different socio-economic status, the descendants of Kwadi speakers and the marginalized communities of the Namib Desert retain a unique Pre-Bantu ancestry that is only found in populations from the Namib desert.In agreement with our previous studies on the maternally-inherited DNA, most genome-wide diversity segregates according to socio-economic status. A lot of our efforts were placed in understanding how much of this local variation and global excentricity was caused by genetic drift – a random process that disproportionally affects small populations – and by admixture from vanished populations
Sandra Oliveira, first author
CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos
InBIO Laboratório Associado
Campus de Vairão, Universidade do Porto, Vairão, Portugal.
With this new information, the researchers could reconstruct the fine-scale histories of contact emerging from the migration of Khoe-Kwadi-speaking pastoralists and Bantu-speaking farmers into southern Africa. Moreover, the study demonstrates that modern DNA research targeting understudied regions of high ethnolinguistic diversity can complement ancient DNA studies in probing the deep genetic structure of the African continent.
No wonder creationism is in crisis and in headlong retreat from the tsunami of evidence which is engulfing it.
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