A new study has been published on the two most relevant African matrilineages of Eurasian origin: M1 and U6. There are others but these two are the ones, together with X1 maybe, who have a more typically African distribution with limited presence in Eurasia.
Erwan Pennarun et al., Divorcing the Late Upper Palaeolithic demographic histories of mtDNA haplogroups M1 and U6 in Africa. BMC Evolutionary Biology, 2012. Open access → LINK [doi:10.1186/1471-2148-12-234]
I must say that I am rather unpersuaded of what the authors have to say, very especially in regards to U6 (but not either on M1) but it is still a study with interesting data for the record.
Very briefly the authors use molecular-clock-o-logy (academic pseudoscience when used as alleged evidence of anything, being as it is mostly speculation with a mathematical pretext), along with very debatable archaeological interpretations, to propose that the expansion of U6 and M1 originate in the mid to late Upper Paleolithic and not, as Olivieri proposed in 2006 (and I rather support) from around the time of the (re-)colonization of West Eurasia c. 50-30 Ka ago.
Whatever the case they leave us with some data on these two lineages and some of their main subclades (not all). These can be found in table 1 and the supplementary materials.
They also provided us with these frequency maps (enriched with approx. linguistic boundaries):
|Absolute frequency of (A) M1 and (B) U6 (and approx. linguistic family boundaries)|
One of the contention points is the Dabban industries of Cyrenaica, which have been argued to be Aurignacoid and therefore correspond to the Homo sapiens (back-)migration into West Asia, Europe and probably also North Africa. The authors cite some references to question that the Dabban are derived from Palestinian technologies but I can only imagine (without getting into the matter in depth as of now) that the issue is under debate (as happens with other technologies from Europe, etc.)
A bigger problem is that no Dabban nor related industries are known to have existed in NW Africa, which is the region where U6 has its greatest basal diversity (clearly) and one of a few regions with greatest M1 basal diversity (the other two being Egypt and Arabia).
U6 from NW Africa or what?
This is another element of the paper that irks me: that the authors happily reject the weight of basal diversity, which is clearly in NW Africa (Morocco notably) and around it (Canary Islands, Iberia). Yet the authors contend:
Whilst several U6 sub-clades seem to be confined to Northwest Africa, this pattern may be the result of drift and founder effects over many thousands of years and does not necessarily suggest that Northwest Africa was the geographic source of U6 dispersals in Africa.
The reasoning is simply not sound, contradicting the logic of greatest parsimony. What they say might hypothetically have happened but has a low chance, notably in absence of any other evidence.
Also the authors argue, based mostly on their own age estimates (which, I insist, are speculations, educated guesses, and cannot ever be used as evidence) that U6 may have arrived with Oranian (aka Iberomaurusian), of quite likely Gravetto-Solutrean South Iberian relatedness. This Western European connection is not only supported by some quite reasonable typological likenesses and mutual influences (back-tipping weapon points in Iberia may have an Aterian origin for example) and chronology of the sites (generally older towards the West) but also by anthropometric considerations (many of the best known Crô-Magnon type specimens, related to Gravettian industry in Europe, are North African Oranian) but also the fact that North Africa has loads of mtDNA of likely West European origin¹ (H1, H3, H4, H7 and V, amounting together to some 30% of the lineages of the region) and that Oranian ancient mtDNA was found to be consistent with this kind of mtDNA pool by Kefi in 2005² (however, as only HVS-I was tested for, the certainty is not 100% - but not your usual African L(xM,N) in any case).
So even if U6 would be of Oranian origin, it would still most likely have coalesced in Morocco (or somewhere nearby), something the authors seem reluctant to admit without offering any clear alternative.
M1 has three regions of high basal diversity (only two subclades exist however M1a and M1b, making this kind of evaluation a bit less certain); they are: Arabia, Egypt and NW Africa.
The closest relative of this haplogroup is M20'51, which is found in SE Asia (Vietnam, South China, Indonesia, etc.) as well as Nepal. I do use this kind of "sister" references also to estimate the most likely origin jointly with basal diversity, and, in this case it suggests that M1 is from Arabia and that North African (and also East African and Highland West Asian) M1 is derived from this origin.
The authors don't seem to take a clear stand in this case either and they even do not mention the East Asian relative, insisting on analyzing only their molecular-clock-o-logic speculations, what are at best only marginally relevant.
However the concede that M1 and U6 were in Africa long before the Afroasiatic expansion.
In the end a somewhat messy study with too much emphasis in the wrong stuff but still good for the data. Check, please table 1 and, if you feel like researching the matter in greater depth the supplemental materials, which are no doubt informative in their own right.
¹ See these papers:
- H. Enafaa, V. M. Cabrera et al., Mitochondrial DNA haplogroup H structure in North Africa. BMC Genetics 2009. Open Access. [LINK]
- L. Cherni et al., Post-last glacial maximum expansion from Iberia to North Africa revealed by fine characterization of mtDNA H haplogroup in Tunisia. American Journal of Physical Anthropology. Pay per view. [LINK]
- Claudio Ottoni et al., Mitochondrial Haplogroup H1 in North Africa: An Early Holocene Arrival from Iberia. PLoS ONE 2010. Open Access. [LINK]