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December 10th, 2014 | #1 |
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Genetic map of sub-Saharan groups reveals rich diversity
05 December 2014
THE biggest study yet of African genetic diversity has shed new light on ancient human migration patterns and offers scientists a rich resource for developing better medical treatments. Since the human genome was first mapped ten years ago, there have been significant advances in understanding how genetic variation affects people’s susceptibility and resistance to disease, but until now most of this work has been undertaken in Europe and the US. As Africans are the most genetically diverse population in the world, the research has the potential to shape a much more nuanced understanding of the interplay between genetics, the environment and disease and has implications beyond the continent’s borders, said Raj Ramesar, professor of human genetics at the University of Cape Town. "Everybody’s ancestors arose in Africa, and it is only in the last 75,000 years that people have populated the rest of the planet: whoever left took only part of that genetic variation with them. African genomes are like a Persian rug in terms of depth and variation, while Asians and Europeans are like an institutional carpet," he said. “Genetic variation gives us a window into both recent and ancient history,” said Michele Ramsay, professor of human genetics at the University of the Witwatersrand and co-author of the study, which was published in the journal Nature this week. “It tells us about genetic selection for traits that may have been an advantage at a particular point in history, but may then turn out to cause susceptibility to disease in a different environment. For example, we know there are two variants in the APOL1 gene that protect people against sleeping sickness, but in the presence of HIV they make people much more predisposed to certain kinds of kidney disease,” she said. The study was carried out by an international collaboration called the African Genome Variation Project which scrutinised genetic material collected from 1,481 individuals from 18 different ethno-linguistic groups in sub-Saharan Africa, including Zulu and Sotho groups. They did 320 whole genome sequences for seven populations, yielding 30-million genetic variations, a quarter of which the scientists said had never been seen before. They found clues about new genetic regions that might be linked to increased susceptibility to diseases, including malaria, lassa fever and high blood pressure. However more research needs to be done to translate this into novel treatments for disease in Africa, said Prof Ramsay. The study had barely scratched the surface of Africa’s genetic diversity, as the continent is home to more than 2,000 ethno-linguistic groups, she said. One of the study’s most intriguing findings lies in the "signatures" of Eurasians found in people living in West Africa today, which indicates that Eurasians migrated back into Africa between 7,500 and 10,500 years ago, returning to the continent that modern humans had left tens of thousands of years before. "They might have brought a ‘wunderlust’ gene with them, which was integrated into other African groups and triggered the Bantu migrations," said Prof Ramesar. The Bantu migrations were a series of migrations that occurred 3,000 to 5,000 years ago and spread people from the Niger-Congo region across most of sub-Saharan Africa. The African Genome Variation Project will make its data freely available to scientists around the world, and complements the work of the Southern African Genome Programme funded by the Department of Science and Technology, said Prof Ramsay. http://www.bdlive.co.za/national/sci...rich-diversity |
December 10th, 2014 | #2 |
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Join Date: Aug 2011
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All they have is the clicking sounds of Southern African Khoisan tribespeople!
Learned PhDs focusing in the wrong direction, making false assumptions and convincing themselves of those falsehoods. Another, is the socalled evidence of tool usage in Ethiopia as being the earliest. Is three scrapes on a rock from 3.39 years ago convincing? Scientists have long thought that the first hominid out-of-Africa migrants were Homo erectus, a species with large brains and a stature approaching human dimensions. Actually, little is known of the origin of our own genus Homo. Since the discovery of the Dmanisi skull, speculation these hominids might be descended from ancestors like H. habilis. In that case, it could be argued that H. erectus itself evolved not in Africa but elsewhere (Eurasia). If so, the early Homo genealogy would have to be drastically revised. |
June 5th, 2015 | #3 | |
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Nothing wrong with 'Out of Africa'
Common name Hofmeyr Skull Species Homo sapiens Age 37,000 years Place discovered South Africa Coordinates: 31°34′S 25°58′E Date discovered 1952 The Hofmeyr Skull is a specimen of a 37,000 year old human skull found in 1952. It is one of the very few modern human skulls discovered in Africa south of Ethiopia and older than 20,000 years. Contents 1 Background 2 Examination 3 Analysis 4 See also 5 Footnotes 6 Further reading Background The skull was found in the 1950s on the surface of an erosion gully, a dry channel bed of the Vlekpoort River, near Hofmeyr, a small town in Eastern Cape, South Africa. No other bones or archaeological artefacts were found in the vicinity at the time of the skull's discovery. The skull is one of only a few African specimens of early modern humans dated over 30,000. Others are much more recent, dated to around 20,000 years ago. In the 1990s, Alan Morris of the University of Cape Town noticed the skull in the Port Elizabeth Museum. He later showed it to Frederick E. Grine, an anthropologist and anatomist at State University of New York at Stony Brook. Grine then led a detailed study of the skull.[1] Examination It was not possible to date the skull using traditional radiocarbon dating, as the carbon had leached out of the bone. Instead, a new method involving a combination of optically stimulated luminescence and uranium-series dating methods was used. The method was developed by Richard Bailey of Oxford University. The earth material from the skull "filling the endocranial cavity" (central portion of the endocranial cavity) was dated using a combination of optically stimulated luminescence and uranium-series dating methods, coupled through a radiation-field model. Based on the assumption that the earth in the skull is about the age of its inhumation and thus the same as the age of the skull,[4] age was estimated to 36,200 ± 3,200 years old.[2] The dating also assumed that the skull "had neither been uncovered long before nor transported any substantial distance before its discovery". The material in the skull can not have been washed out or replaced by water flowing down the gully because "the force required to scour the inner-most sediments would certainly have resulted in substantial damage" of the skull, and the skull did not appear to the dating team to have been damaged that much. The anterior part of the lower facial skeleton has been damaged. The angle of the mandible, the mastoid process of the right temporal, and much of the occipital are not present. The coronal suture is obliterated and the third molars are heavily worn, suggesting that the specimen reached adulthood. The skull's owner had been wounded over his left eye and the wound had partially healed before death. The most severe damage to the skull, however, was caused during its time in storage and "mishandling" after its 1950 discovery. A lost bone is documented on pictures from 1968 and 1998. Analysis The Hofmeyr fossil was compared with skulls from Sub-Saharan Africa, including those of the KhoeSan, who are geographically close to the site of the find. Using 3-dimensional measurement and mapping techniques, the study found that the Hofmeyr Skull is rather distinct from those of recent Sub-Saharan Africans, and that its closest affinities were with the people who lived in Eurasia in the Upper Paleolithic period, at the same time as the Hofmeyr skull. Alan Morris said that the skull's owner "would not look like modern Africans or like modern Europeans, or like modern Khoisan people, but he is definitely a modern human being". The skull demonstrates that humans in Africa 36,000 years ago resembled those in Eurasia. This evidence supports the recent single-origin hypothesis, which suggests that anatomically modern humans evolved in Africa before 200,000 to 100,000years ago, with members of one branch leaving Africa between 65,000 and 25,000 years ago, spreading to the rest of the world and replacing other Homo species already there. Quote:
Eurasians are the native people of Africa! Last edited by Pamela Ross; June 5th, 2015 at 11:50 AM. |
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June 5th, 2015 | #4 | |
Charachature incarnate
Join Date: May 2014
Location: Already in accordance with the future Repulsive Tapir Avatar Mandate
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This is one well-known example. Could almost pass for a Tamil type without the Abo features. Weird explanation behind the pair-up. More than likely, citizenship perks:
https://www.google.nl/search?q=cnn+a...F%3B1200%3B798
[removed link since it triggers antivirus -varg] Quote:
__________________
youtube.com/watch?v=-EDJRcwQvN4 youtube.com/watch?v=S0lxK5Ot5HA youtube.com/watch?v=HFv92Lc8FXg Last edited by varg; June 11th, 2015 at 10:24 AM. Reason: removed nigeria website since it triggers antivirus |
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June 5th, 2015 | #5 |
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June 5th, 2015 | #6 |
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Rape would explain it. Lots of rape.
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June 11th, 2015 | #7 | |
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