Angela
Elite member
- Messages
- 21,823
- Reaction score
- 12,329
- Points
- 113
- Ethnic group
- Italian
See:
https://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1001373
It's the big guns: Reich, Patterson etc. I don't know why they worked with Moorjani, who vastly inflated it the first time around.
"Previous genetic studies have suggested a history of sub-Saharan African gene flow into some West Eurasian populations after the initial dispersal out of Africa that occurred at least 45,000 years ago. However, there has been no accurate characterization of the proportion of mixture, or of its date. We analyze genome-wide polymorphism data from about 40 West Eurasian groups to show that almost all Southern Europeans have inherited 1%–3% African ancestry with an average mixture date of around 55 generations ago, consistent with North African gene flow at the end of the Roman Empire and subsequent Arab migrations. Levantine groups harbor 4%–15% African ancestry with an average mixture date of about 32 generations ago, consistent with close political, economic, and cultural links with Egypt in the late middle ages. We also detect 3%–5% sub-Saharan African ancestry in all eight of the diverse Jewish populations that we analyzed. For the Jewish admixture, we obtain an average estimated date of about 72 generations. This may reflect descent of these groups from a common ancestral population that already had some African ancestry prior to the Jewish Diasporas.Author Summary
Southern Europeans and Middle Eastern populations are known to have inherited a small percentage of their genetic material from recent sub-Saharan African migrations, but there has been no estimate of the exact proportion of this gene flow, or of its date. Here, we apply genomic methods to show that the proportion of African ancestry in many Southern European groups is 1%–3%, in Middle Eastern groups is 4%–15%, and in Jewish groups is 3%–5%. To estimate the dates when the mixture occurred, we develop a novel method that estimates the size of chromosomal segments of distinct ancestry in individuals of mixed ancestry. We verify using computer simulations that the method produces useful estimates of population mixture dates up to 300 generations in the past. By applying the method to West Eurasians, we show that the dates in Southern Europeans are consistent with events during the Roman Empire and subsequent Arab migrations. The dates in the Jewish groups are older, consistent with events in classical or biblical times that may have occurred in the shared history of Jewish populations.""
My initial reaction is big whoops, but whatever.
]
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I never put my faith 100% on their dating of admixture. It's so often wrong. Given the difference between the scores of Southern Italy (still very small) and northern Italy, which indicates to me it probably diffused northward, and the fact it's in Spain, I would bank on the Muslim conquests as the time period. There weren't very many SSA people in the Empire, and we know that the Muslim forces contained people with SSA ancestry (we have the ancient DNA to prove it), and that they also imported slaves to work the lands they conquered.
Interesting it's so small, actually.
People shouldn't be surprised how much there is in certain parts of the Levant. Besides dribbles for thousands of years, perhaps, there is slavery to consider and movement of Yemeni tribes into the Levant. You can see it in the Palestinians and the Bedouin. It's double the amount in the Druze. I have to look it over carefully. I wonder if figures exist for the Lebanese and Syrians and if they are closer to the Druze, and how much the Saudis have. I would imagine the latter have more. Between this ancestry and all the Iranian, no wonder the closest people to the Anatolian Neolithic are Southern Europeans.
I don't at all understand why they wouldn't give us the Greek figures. They had to divide the Italians up into three clusters. Why couldn't they have done the same for the Greeks? The split was probably Aegean Greeks, Peloponnese, and Thessaloniki.
https://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1001373
It's the big guns: Reich, Patterson etc. I don't know why they worked with Moorjani, who vastly inflated it the first time around.
"Previous genetic studies have suggested a history of sub-Saharan African gene flow into some West Eurasian populations after the initial dispersal out of Africa that occurred at least 45,000 years ago. However, there has been no accurate characterization of the proportion of mixture, or of its date. We analyze genome-wide polymorphism data from about 40 West Eurasian groups to show that almost all Southern Europeans have inherited 1%–3% African ancestry with an average mixture date of around 55 generations ago, consistent with North African gene flow at the end of the Roman Empire and subsequent Arab migrations. Levantine groups harbor 4%–15% African ancestry with an average mixture date of about 32 generations ago, consistent with close political, economic, and cultural links with Egypt in the late middle ages. We also detect 3%–5% sub-Saharan African ancestry in all eight of the diverse Jewish populations that we analyzed. For the Jewish admixture, we obtain an average estimated date of about 72 generations. This may reflect descent of these groups from a common ancestral population that already had some African ancestry prior to the Jewish Diasporas.Author Summary
Southern Europeans and Middle Eastern populations are known to have inherited a small percentage of their genetic material from recent sub-Saharan African migrations, but there has been no estimate of the exact proportion of this gene flow, or of its date. Here, we apply genomic methods to show that the proportion of African ancestry in many Southern European groups is 1%–3%, in Middle Eastern groups is 4%–15%, and in Jewish groups is 3%–5%. To estimate the dates when the mixture occurred, we develop a novel method that estimates the size of chromosomal segments of distinct ancestry in individuals of mixed ancestry. We verify using computer simulations that the method produces useful estimates of population mixture dates up to 300 generations in the past. By applying the method to West Eurasians, we show that the dates in Southern Europeans are consistent with events during the Roman Empire and subsequent Arab migrations. The dates in the Jewish groups are older, consistent with events in classical or biblical times that may have occurred in the shared history of Jewish populations.""
My initial reaction is big whoops, but whatever.
]
I never put my faith 100% on their dating of admixture. It's so often wrong. Given the difference between the scores of Southern Italy (still very small) and northern Italy, which indicates to me it probably diffused northward, and the fact it's in Spain, I would bank on the Muslim conquests as the time period. There weren't very many SSA people in the Empire, and we know that the Muslim forces contained people with SSA ancestry (we have the ancient DNA to prove it), and that they also imported slaves to work the lands they conquered.
Interesting it's so small, actually.
People shouldn't be surprised how much there is in certain parts of the Levant. Besides dribbles for thousands of years, perhaps, there is slavery to consider and movement of Yemeni tribes into the Levant. You can see it in the Palestinians and the Bedouin. It's double the amount in the Druze. I have to look it over carefully. I wonder if figures exist for the Lebanese and Syrians and if they are closer to the Druze, and how much the Saudis have. I would imagine the latter have more. Between this ancestry and all the Iranian, no wonder the closest people to the Anatolian Neolithic are Southern Europeans.
I don't at all understand why they wouldn't give us the Greek figures. They had to divide the Italians up into three clusters. Why couldn't they have done the same for the Greeks? The split was probably Aegean Greeks, Peloponnese, and Thessaloniki.