Wednesday, October 5, 2016

Sudanese Arab and Nubian mtDNA is mostly non-Eurasian?

I was looking back at some old data like from Hisham Yousif Hassan Mohamed's 2009 thesis and there's something intriguing about Sudanese Arab and Nubian mtDNA:

There aren't too many samples but there's definitely a pattern going on with the Nubians and the Arakien, Gaalien and Meseria (the three groups used to create the "Arab" grouping above); most of their mtDNA is non-M&N. The overwhelming majority of their maternal lineages look to be African rather than West Eurasian.

This is surprising because it's notably different from how things are with Horn African Cushitic and Ethiopian Semitic speakers as well as Bejas who are a northern Sudanese population like Nubians and Sudanese Arabs (Bejas are Cushitic speakers though):




Somalis, Amharas, Oromos, Tigrinyas, Beta Israels and Bejas all have a more balanced mtDNA profile. 40-60, 50-50, 50-50, 60-40, 50-50 and 30-70 are the types of frequency ratios you see in terms of Eurasian (West Eurasian derived) and African (non-M&N) lineages.

Now, the thesis sample sizes arguably aren't large, to be honest, but it's still notable that Sudanese Arabs and Nubians have very low frequencies for M&N lineages even when the sample sizes are comparable to those of the Horn African groups and Bejas. It's also notable that this pattern holds in all of the groups (the Nubians and the three Arab groups).

Despite this, they actually have high frequencies for West Eurasian Y-DNA lineages (i.e. J1):

Fifty to seventy percent or more of their Y-DNA lineages are of clearly Eurasian (West Eurasian derived) origins. [note] A friend once brought up the idea that this implies much of their West Eurasian ancestry since after the Sudanese Neolithic (something Cushitic speakers from the Horn of Africa seemingly descend from) is probably "male mediated" as in what largely happened is that males carrying substantive West Eurasian ancestry intermixed with local Northeast African women and brought lineages like Y-DNA J & I in abundance.

I do wonder if that's seriously the case...



This would be unlike the case in the Horn where there's about 5-30% Y-DNA J (mainly J1) among Cushitic and Ethiopian Semitic speakers alongside 5-35% Y-DNA T as well. [note]

The Horn looks somewhat more "balanced" in terms of Y-DNA & mtDNA lineages. There's a substantial amount of both blatantly West Eurasian and more local African lineages on both a maternal and paternal level but things look quite skewed in the case of Nubians and Sudanese Arabs who look to have very low M&N lineage frequencies mtDNA wise but very high frequencies for lineages descended from F in terms of Y-DNA.

Should be interesting to see more and more mtDNA & Y-DNA data from Nubians and Arabic speaking groups in Sudan to see how much this pattern holds in the future. Getting mtDNA results from different Arab groups is also key as I've only really seen results for three groups at this point.

12 comments:

  1. Hi broski , great article again, been long time bro :)
    I was banned off anthrogenica even my IP adress :( , is there anyway you can help me get an unban ?? I pay for amnesty lolz. Greets !

    ReplyDelete
    Replies
    1. Apologies, my friend, but I can't really help you here. I remember asking the staff why you were banned and they seem to believe, with some evidence, that you were using someone's identity or something (I don't recall all the details). But you're permabanned now and they're unlikely to resend that. You can email me if you wish to stay in contact, however:

      Awaleking@gmail.com

      Delete
  2. I would think that the Beja tend more to the "Horner" model because they live close to the Red Sea and the Eurasian (actually Asian, West Asian to be even more specific) influence in the area seems to have arrived primarily across that narrow sea, I don't know exactly when but maybe to a large extent in the post-Neolithic period, with a clearly strong push in Ethiopia particularly (but not really in Sudan/Nubia, a more inlander area centered around the Nile and also one holding high densities since probably very very early).

    As for the Y-DNA, I would particularly discern between J1, which is extremely diverse in NE Africa, almost as much as in West Asia, and J2, which seems a marker of Semitic expansion quite specifically (in Africa, not in other areas like Europe, where it's probably quite older). This is very different to what we see for example in NW Africa, where J1 has very low diversity (and IMO should come mostly from the Nile basin, via the early Afroasiatic/Capsian culture expansion). My opinion is that J1 in the Nile basin and surely also in The Horn is much older than Mesolithic, maybe even from the time of the LSA genesis (which must be related to the Eurasian "Upper Paleolithic" very tightly). When we look at the IJ haplogroup, we see that the first branching is I (Europe) and J (West Asia) but J1 and J2 must have branched out soon afterwards and the diversity of J1 in NE Africa is really high (deserving surely better research than available so far). So for me J1 must have arrived to NE Africa very early via Palestine and Egypt (we also see Egypt to have, almost exclusively, a very early diverged West Eurasian mtDNA lineage: X1, and all this may be loosely related to the expansion of Y-DNA T and mtDNA M1 in East Africa).

    What I mean is that there are surely older and more recent West Asian lineages at play here. Also, it's not at all impossible that some E1b may have gone first to West Asia (clearly from the Sudan/Nubia area originally) and back to NE Africa with the Semites. We'd need more detail to clarify in all cases.

    ReplyDelete
  3. BTW, can you confirm if (Y-DNA) I-M170 is correct and not some other haplogroup? It would be quite "revolutionary" if confirmed because so far I has been considered an almost strictly European lineage (however ancient Guanches carried it at non-anecdotal frequencies: c. 7%). I knew about R1b and J1 in Sudan being important and probably quite old (how much?) but it's the first time I read about I, what is most intriguing if confirmed.

    ReplyDelete
    Replies
    1. "BTW, can you confirm if (Y-DNA) I-M170 is correct and not some other haplogroup?"

      It's certainly what the paper/thesis claims:

      http://oi64.tinypic.com/25je786.jpg

      The entire thesis can be attained via the hyperlinked first reference in this post's reference list.

      "It would be quite "revolutionary" if confirmed because so far I has been considered an almost strictly European lineage (however ancient Guanches carried it at non-anecdotal frequencies: c. 7%)."

      Oh, that's quite interesting. I'm not too familiar with Y-DNA I's frequencies, phylogeny and such and such so I wasn't aware that this would be so surprising (granted, I was well aware that it, as a whole, was a very "European" Y-DNA marker). You should review the thesis for yourself and see if they got anything wrong because if they didn't; this is quite interesting, I suppose. :-)

      Delete
    2. Sorry for requesting confirmation, at first I thought it could be a typo but then I realized it was not.

      Haplogroup I is the "most European" of all Y-DNA lineages, it's not just modern frequencies but also it has been proven once and again in recent years that most (almost all) sampled Paleolithic Europeans carried it. In terms of modern frequencies (see for instance: https://en.wikipedia.org/wiki/Haplogroup_I-M170) it is somewhat common (outside of Europe) in places like Turkey, Kurdistan or Iran but clearly drops to near zero south of that "highlander" or "northerner" area of West Asia (2% in Syria and Libya, 1% in Morocco and Egypt, 0% in Algeria, etc.) So the frequencies among Nubians and such are quite unexpected. For R1b or even more clearly for J1 you can say that they arrived from West Asia at some point but for I?!

      To me this may well be related to a possible W→E flow from Morocco in the late Upper Paleolithic, which we can also track in mtDNA U6a (with U6a1 maybe back-migrating Westward with Capsian/Afroasiatic flows already in the Epipaleolithic). While U6 used to be considered an African lineage (or Eurasian derivation necessarily) it has been now demonstrated that the origin must be at the Gibraltar Strait (both sides host the top basal diversity, including the rare U6c) and, crucially, an instance of U6 was sequenced in Aurignacian Romania (quite unexpected but reinforcing the conjecture that it may have arrived to Africa via Europe and not West Asia).

      As you may know there's been historically a big debate on the origins of the first NW African Upper Paleolithic, originally called Iberomaurusian, then Oranian (the naming controversy is related to the origins controversy directly). Today it seems quite likely that the European Solutrean origin theory is the correct one: oldest sites like Taforalt are to the West, close to Gibraltar Strait, the technical similitude is notable but also there is a lot of Iberian-like mtDNA, and autosomal DNA, in NW Africa, cf. Enafaa 2009, Cherni 2008 and recently also Kefi 2016 seems to identify such kind of lineages in Taforalt and Afalou, with very little African genetics (although at least one sequence they seem to have misidentified).

      So my "theory" is that there was a major genetic flow from Iberia to NW Africa at the Iberomaurusian genesis c. 22 Ka ago, then some flow from NW Africa to the Nile basin (time?, it's based only on genetics) and then a back-flow from the Nile basin, Nubia primarily, to NW Africa with Capsian culture, probably already Afroasiatic (pre-proto-Berber) speakers that mostly shaped the current genetic pool, with a clear gender bias ("European" Y-DNA was wiped out or almost but mtDNA was largely preserved).

      Of course it needs all kinds of confirmations but that can only happen with further research in the archaeogenetic, modern genetic and archaeological fields. In any case I find it quite parsimonious on light of the available data, which includes an insistent European-like autosomal DNA component in all North Africa, and not just West-Asian-like (cf. Henn 2012 for instance). Of course, the modern European genetic pool has a strong West Asian Neolithic influence, so it can be confusing, but it also retains a significant distinctiveness that comes from Paleolithic Europeans directly.

      ...

      Delete
    3. ...

      "You should review the thesis for yourself"...

      Sure, I just couldn't find the link. I found one now but the thesis is not openly available (there's a "request" button, probably only for university workers).

      Delete
    4. Here's the thesis:

      https://drive.google.com/file/d/0B2ARnUeK-Y8WRGVEZU55ZkQ1QzA/view?usp=sharing

      All 231 pages. :-)

      Delete
    5. Thank you very much, Awale. :)

      Delete
  4. If we go with your friend's afmd idea of past "male mediated" West-Eurasian ancestry, it seems odd B-M60 would be found in modern Nubians but wouldn't be detected in past Neolithic, Meroitic, Post-Meroitic and Christian periods (Hassan, 2009). Could this just be attributed to a low resolution of samples? if not, this is truly puzzling

    I do wonder if B-M60 in modern Nubians is closely related to the B haplogroups detected in modern Sudanese Copts (Hassan, 2008). I also wonder if the B haplogroup detection in either of these two groups is as recently related to Nilotic populations as has been widely suggested -- there's quite a number of FTDNA B Haplogroup Project members from the Arabian Peninsula (Saudi Arabia, Yemen, UAE), could we consider some to be relics of a deeper time in human history? I recall reading your post on "The East African Cluster" and not confusing recent and ancient detection among certain Arab groups...

    "the East African cluster exists in Levantines right down to Ashkenazi Jews & Negev Bedouin at a rate of about ~1-15% and in Arabians themselves as you can observe in Hodgson et al. itself at a rate of ~5-15% [4] [1]. Much of its presence in these populations given its spread seems quite extensively ancient (its ancient nature is likely even greater in North Africans) and this component's spread is not to be conflated with the Arab Slave Trade though some of its spread might be owed to this."

    ReplyDelete
    Replies
    1. As complementary info to your mention of Y-DNA B in Peninsular Arabians, I will add that it has also been found in Hormuzgan (Iran) and some population of Afghanistan (Hazaras?), in both cases at small but non-negligible frequencies. I do wonder how old is this lineage in West Asia and the process of its expansion, lacking an answer, and I would speculate that it may be related to the Upper Paleolithic/Late Stone Age genesis some 50-40 Ka BP (but it could also be more recent). There's also a significant figure of mtDNA L(xM,N) lineages in Peninsular Arabia, many of which are too rare in Africa today to be explained in terms of Indian Ocean trade (incl. slave trade), they look older, stemming from older African genetic landscapes, but how old exactly?

      Delete