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Post by Charlie Bass on Sept 16, 2010 13:36:29 GMT -5
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Post by thought on Sept 18, 2010 15:05:24 GMT -5
"The genetic data appear to be consistent with the archaeological and linguistic data indicative of extensive population interactions between North African and Middle Eastern populations. ..... haplogroup J (M267) appears to have arisen in the Middle East over 20 kya and subsequently spread into northern Africa ."
Thought Writes:
These authors comments on Haplogroup J are an oversimplification. Yes, it is true that some Hg J may have made its way into NE Africa during the Holocene. But this is in no way comparable to the population founding effect of Hg E sublineages and the spread of these lineages around the circum-Mediterranean basin.
An interesting comparision can be found in the fact that unlike Hg E1b1b, there are no known African specific sublineages of Hg J in Africa. This implies a recent dispersal of Hg J into Africa (i.e., not enough time to derive sublineages).
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Post by sundiata on Sept 24, 2010 10:47:03 GMT -5
^Agreed. Their main emphasis here was the bio-directional gene flow, though they could have done more exploring. For instance, most of the J in North Africa, according to Nebel (2002) was introduced in post-Islamic times. So because the Hg originated 20kya, doesn't mean that it was able to immediately diffuse into North Africa, or that it did.
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Post by clydewin98 on Oct 27, 2010 11:48:46 GMT -5
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Post by truthcentric on Oct 29, 2010 23:27:16 GMT -5
These authors comments on Haplogroup J are an oversimplification. Yes, it is true that some Hg J may have made its way into NE Africa during the Holocene. But this is in no way comparable to the population founding effect of Hg E sublineages and the spread of these lineages around the circum-Mediterranean basin. An interesting comparision can be found in the fact that unlike Hg E1b1b, there are no known African specific sublineages of Hg J in Africa. This implies a recent dispersal of Hg J into Africa (i.e., not enough time to derive sublineages). Don't Luis et al 2004 (The Levant versus the Horn of Africa: Evidence for Bidirectional Corridors of Human Migrations) estimate the arrival of J into Egypt at around 16-11 kya? Or can Y-chromosome expansion date estimates be mistaken? |
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Post by zarahan on Oct 30, 2010 22:24:07 GMT -5
They reference the 2009 Tishkoff study which found as to East Africa:  They also say: "The pattern of genetic variation in Africa is also consistent with geographic barriers limiting gene flow as exampled by the geographic/genetic distinction between northern African and sub-Saharan African populations. This may be so as to the modern era, but the Sahara was once a lush greenbelt covering one-third of Africa and was not the barrier of the modern era. And the Saharan barrier did not stop Saharan and Sudanic peoples from moving into the Nile Valley to found ancient Egypt. Indeed scientific data shows said peoples were tropically adapted, coming from the south. Southern Egypt itself falls within the tropical climatic zone with the north falling into the arid tropics or subtropics.  '   |
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