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Rare mitochondrial lineages with relict distributions can sometimes be disproportionately informative about deep events in human prehistory. We have studied one such lineage, haplogroup R0a, which uniquely is most frequent in Arabia and the Horn of Africa, but is distributed much more widely, from Europe to India. We conclude that: (1) the lineage ancestral to R0a is more ancient than previously thought, with a relict distribution across the Mediterranean/Southwest Asia; (2) R0a has a much deeper presence in Arabia than previously thought, highlighting the role of at least one Pleistocene glacial refugium, perhaps on the Red Sea plains; (3) the main episode of dispersal into Eastern Africa, at least concerning maternal lineages, was at the end of the Late Glacial, due to major expansions from one or more refugia in Arabia; (4) there was likely a minor Late Glacial/early postglacial dispersal from Arabia through the Levant and into Europe, possibly alongside other lineages from a Levantine refugium;
and (5) the presence of R0a in Southwest Arabia in the Holocene at the nexus of a trading network that developed after ~3 ka between Africa and the Indian Ocean led to some gene ow even further a eld, into Iran, Pakistan and India.

Low-frequency mitochondrial (and Y-chromosome) lineages with a relict distribution can be disproportionately informative about deep events in human prehistory. Mitochondrial DNA (mtDNA) haplogroups N1a1a and X, which have both been recovered from prehistoric remains as well as from living people, are good examples1–3. Another such lineage, with a very di erent distribution, is mtDNA haplogroup R0a, although to date it has never been recovered from prehistoric remains so we are entirely reliant on the modern diversity to draw conclusions about its history.


R0a is unique in reaching very high frequencies in the Arabian Peninsula, and is also common on the far side of the Bab el-Mandeb strait (or “Gate of Tears”), in the Horn of Africa, along with several other haplogroups of Eurasian origin.


More generally, the Horn of Africa is exceptional in harbouring very high mtDNA haplogroup diversity4, and populations in the Horn have signi cant non-autochthonous African ancestry across the genome5–10.


Recent studies of complete human genomes have concluded that this 30–50% of non-African legacy in Cushitic- and Semitic-speaking populations is the result of admixture from Arabia beginning ~3,000 years ago (3 ka)11,12, at a time when common cultural features developed across the Horn and southern Arabia13, suggesting a link with the origin of the Ethiosemitic languages14. However, others have argued that such autosomal dating needs to be treated with considerable caution10,15. Moreover, some have also proposed that the source for the Horn lineages was in the Levant rather than Arabia10,11, whilst others have provided further evidence in favour of Arabia15.

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Posts: 22234 | From: האם אינכם כילדי הכרית אלי בני ישראל | Registered: Nov 2010  |  IP: Logged | 

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Originally posted by xyyman:
This was discussed already but as a reminder...

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Posts: 22234 | From: האם אינכם כילדי הכרית אלי בני ישראל | Registered: Nov 2010  |  IP: Logged | 

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Originally posted by DD'eDeN:
xyyman: "That is like saying since China has the most people on the earth then all humans came from China...lol!

That game is not played any more! lol! "
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Africa has highest diversity. That indicates a past large population, right? China has present large population. What's the difference? Lotta people today vs lotta people yesterday...neither says where they came from long before (eg. Homo erectus...) when populations were tiny.

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Posts: 12143 | From: When you have eliminated the impossible, whatever remains, however improbable | Registered: Jun 2007  |  IP: Logged | 

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Originally posted by DD'eDeN:
xyyman: "That is like saying since China has the most people on the earth then all humans came from China...lol!

That game is not played any more! lol! "
- - -

Africa has highest diversity. That indicates a past large population, right? China has present large population. What's the difference? Lotta people today vs lotta people yesterday...neither says where they came from long before (eg. Homo erectus...) when populations were tiny.

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Posts: 22234 | From: האם אינכם כילדי הכרית אלי בני ישראל | Registered: Nov 2010  |  IP: Logged | 

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^^ Cosign. The problem as usual is they fail to explain how these ancestral clades are non-African in the first place. We know Arabia was the launch pad or source for OOA, but again how different were these early or first Arabians from their African brethren right next door?

And just to give a clearer picture here is a clade tree showing the mitochondrial clades with hg R emboldened



There is a general consensus among experts that the OOA macroclade L3 is African in origin whereas its two daughter clades M & N are 'Eurasian' that is they arose in Eurasia. But if they arose in Arabia right next to Africa, just how "Eurasian" could they be??

What's worse is that Swenet cited a recent study on Saudi Arabian genomes here where they find L3's presence in Arabia to be older than they previously thought but now they're questioning if L3 is African!

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Originally posted by Ish Gebor:

Rare mitochondrial lineages with relict distributions can sometimes be disproportionately informative about deep events in human prehistory. We have studied one such lineage, haplogroup R0a, which uniquely is most frequent in Arabia and the Horn of Africa, but is distributed much more widely, from Europe to India. We conclude that: (1) the lineage ancestral to R0a is more ancient than previously thought, with a relict distribution across the Mediterranean/Southwest Asia; (2) R0a has a much deeper presence in Arabia than previously thought, highlighting the role of at least one Pleistocene glacial refugium, perhaps on the Red Sea plains; (3) the main episode of dispersal into Eastern Africa, at least concerning maternal lineages, was at the end of the Late Glacial, due to major expansions from one or more refugia in Arabia; (4) there was likely a minor Late Glacial/early postglacial dispersal from Arabia through the Levant and into Europe, possibly alongside other lineages from a Levantine refugium;...

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According to a Rose & Petraglia et ales. study there were three refugia in Arabia during the LGM as shown below.



No doubt genetic bottlenecks formed in these three refugia with limited if any geneflow until humid conditions led to population expansions from these three centers. However, note the coastlines during the LGM that are now submerged in a better picture below.



Note the Bab-el-Mandeb straits during the LGM were much narrower than they are today with one section being as narrow as a river! Note also according to the study that Ish Gebor cited, there was also a refugium in the African side parallel to that on the Arabian side, and with only essentially a river separating them there was bound to be geneflow between the two.

This is why I am always skeptical about what these experts consider African vs. 'Eurasian' with these early OOA clades and why I refer back to Keita et al. (2008) from In Hot Pursuit of Language in Prehistory:
The issue of how much Paleolithic migration from the Near East there may have been is intriguing, and the mitochondrial DNA variation may need to be reassessed as to what can be considered to be only of "Eurasian origin" because if hunters and gatherers roamed between the Saharan and supra-Saharan regions and Eurasia it might be difficult to determine exactly "where" a mutation arose

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and (5) the presence of R0a in Southwest Arabia in the Holocene at the nexus of a trading network that developed after ~3 ka between Africa and the Indian Ocean led to some gene ow even further a eld, into Iran, Pakistan and India.

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Low-frequency mitochondrial (and Y-chromosome) lineages with a relict distribution can be disproportionately informative about deep events in human prehistory. Mitochondrial DNA (mtDNA) haplogroups N1a1a and X, which have both been recovered from prehistoric remains as well as from living people, are good examples1–3. Another such lineage, with a very divergent distribution, is mtDNA haplogroup R0a, although to date it has never been recovered from prehistoric remains so we are entirely reliant on the modern diversity to draw conclusions about its history.

R0a is unique in reaching very high frequencies in the Arabian Peninsula, and is also common on the far side of the Bab el-Mandeb strait (or “Gate of Tears”), in the Horn of Africa, along with several other haplogroups of Eurasian origin.

More generally, the Horn of Africa is exceptional in harbouring very high mtDNA haplogroup diversity4, and populations in the Horn have signi cant non-autochthonous African ancestry across the genome5–10.

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Recent studies of complete human genomes have concluded that this 30–50% of non-African legacy in Cushitic- and Semitic-speaking populations is the result of admixture from Arabia beginning ~3,000 years ago (3 ka)11,12, at a time when common cultural features developed across the Horn and southern Arabia13, suggesting a link with the origin of the Ethiosemitic languages14. However, others have argued that such autosomal dating needs to be treated with considerable caution10,15. Moreover, some have also proposed that the source for the Horn lineages was in the Levant rather than Arabia10,11, whilst others have provided further evidence in favour of Arabia15.

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