On Sunday, February 16, 2020 at 9:45:18 PM UTC-5, Gloria Emeagwali wrote:
This reminds me of the sloppy work done on what was labeled ancient Egyptian DNA in 2017. The researchers went to a fringe area of Egypt, at Abusir - el- Meleq, and deliberately ignored the core areas of continuous occupation of indigenous Egyptians about 300 miles away. The sample was not representative, and could even be that of West Asian Hyksos who invaded and occupied Egypt during the time frame cited, but they were in a hurry to hit the headlines, and thought they could fool the uninformed.I interpret the terminology "ghost" here to imply unknown and mysterious. David Reich hints to this "ghost" phenomenon, in his chapter 9 , on Africa, in "Who we are and how we got here."He talks about "a mixture of two highly differentiated human populations in close to equal proportions."p.211.
Were the Neanderthals and Denisovans originally from Africa?Gloria EmeagwaliSent from my iPhone--The title of Okey Iheduru's posting on this subject (Feb. 13) is sensational and misleading (BREAKING NEWS!!! The Yoruba Descended From Archaic "Ghost' Ancestor- Archaeology). It is neither consistent with the title of the story he shared nor with the contents of the publication by the Israeli newspaper, Haaretz. The title of the article in Haaretz is "The Ghost' Ancestor Detected in DNA of Today's West Africans. And, the study is not based on any archaeological finding.
The Haaretz article itself is a poor online presentation of the scientific study recently published in Science Advances titled "Recovering signals of ghost archaic introgression in African populations." There are three problems that possibly led to the sensational title used by Okey Iheduru. First, most historical geneticists have a poor understanding of culture and human history. Second, most humanists and social scientists lack a basic understanding of the science of DNA. Third, as a result of 1 and 2, the translations of DNA data/findings into the public domain and historical narrative tend to come with inaccuracies and deliberate/unscrupulous manipulation. For those who may be wondering what this is all about, the publication in Science Advances reached this straightforward conclusion:
The present-day West Africans carry the genes of archaic Homo sapiens and possibly the DNA of a branch of Homo erectus. That is, anatomically modern humans (Homo sapiens sapiens) who emerged from the archaic Homo sapiens about 300,000 years ago interbred with their archaic Homo sapiens and Homo erectus cousins before those two subspecies died out. This is not surprising. The same thing happened in other parts of the world. For example, when Homo sapiens sapiens arrived in Europe and Asia (from Africa) between 100,000 and 40,000 years ago, they also interbred with the native Neanderthals and Denisovans (the versions of archaic Homo sapiens in those regions).
The reference to the Yoruba and Mende in the original Science Advances study came about because the genetic samples that the authors used in their study were collected from individuals living in these two culture areas. These samples are currently banked at Yale University's Human Relations Area File. Most geneticists interested in early human migrations and evolution often use these samples in their laboratory work. But there are problems with the methodology by which the sample was obtained. The so-called "Yoruba DNA" samples were collected in Ibadan from members of the same family across three generations. Those who collected these samples did not do any historical study to understand the ancestry of this family. We don't know how this arrived in Ibadan, from where, and when. Anyone who knows the history of Ibadan and what DNA is about would giggle at the sloppy way the data was collected, and how this data is now called "Yoruba DNA." This is a misnaming. We can talk of Yoruba culture and history, but there is no peculiar Yoruba DNA found in an isolated Yoruba population. So, what has become "Yoruba or Mende DNA" in genetic studies is no more than two samples (populations) of DNA from West Africa.
Those interested in a more informed popular version of the original research (beyond the sensation) should read this Feb 12 New York Times article, "Ghost DNA Hints at Africa's Missing Ancient Humans". And those interested in the original publication in Science Advances should visit https://advances.sciencemag.
org/content/6/7/eaax5097 .
Akin Ogundiran
UNC Charlotte
On Thursday, February 13, 2020 at 2:56:40 PM UTC-5, okeyiheduru wrote:
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