March 27, 2012

Claim that some African matrilineages in Europe are pre-Neolithic

A new paper estimates that some 35% or the L(xM,N) lineages of Europe are prehistorical and even pre-Neolithic:


Abstract

Mitochondrial DNA (mtDNA) lineages of macro-haplogroup L (excluding the derived L3 branches M and N) represent the majority of the typical sub-Saharan mtDNA variability. In Europe, these mtDNAs account for <1% of the total but, when analyzed at the level of control region, they show no signals of having evolved within the European continent, an observation that is compatible with a recent arrival from the African continent. To further evaluate this issue, we analyzed 69 mitochondrial genomes belonging to various L sublineages from a wide range of European populations. Phylogeographic analyses showed that ∼65% of the European L lineages most likely arrived in rather recent historical times, including the Romanization period, the Arab conquest of the Iberian Peninsula and Sicily, and during the period of the Atlantic slave trade. However, the remaining 35% of L mtDNAs form European-specific subclades, revealing that there was gene flow from sub-Saharan Africa toward Europe as early as 11,000 yr ago.

See also the press release at Eureka Alert.

I do not have access but it seems obvious that the authors are using molecular-clock-o-logy, which is not really reliable, depending on too many assumptions. However they tend to fail towards too recent, so maybe their estimates of 11 Ka can be in fact something like 22 Ka and therefore consistent with the more than likely interactions between SW Europe and NW Africa at the genesis of Oranian culture, which is probably the origin of SW European-derived mtDNA in North Africa.


Update:

I got a copy and some stuff is indeed informative:

Fig. 1 spread of (a) paragroup L(xM,N) and (b) L1 (crosses mark sampling sites)

Fig. 3 apportion of the L(xM,N) lineages and of the probable origin regions

The most common lineages are L1b and L2a.

Most European L1b appears to have spread from the Iberian peninsula where it is most concentrated in the area of Salamanca, being loosely consistent with other North African genetic presence in the peninsula, generally concentrated in the Western third (and with some even greater frequency in the mountain areas of the old Kingdom of León. Some of these lineages have not been found among a sample of 73 L1b mitogenomes from Africans and African Americans (fig. 2), what brings the authors to consider them potentially local European (or in some cases NW African) developments. These are:
  • L1b1a11 (Slovenia, Switzerland and Ireland), its sister lineages are found one in Jordan (unnamed) and another (L1b1a3) among Nigerians, Gabonese, African-Americans and some Portuguese.
  • L1b1a6a (Portugal, Spain and Britain): just one branch of several, all the others in L1b1a6 are West African
  • L1b1a9 (Spain, Italy, France and Morocco): either European or NW African
  • L1b1a13 (Tunisia and Italy): surely Tunisian originally
  • L1b1a12 (Tunisia, Spain and Portugal): again surely original from Tunisia
  • L1b1a14 (Italy and France)
  • L1b1a8 (Spain and Russia)
Another very characteristic and also arguably European-specific lineage is L3d1b1a, which is found only in Italy.

While the authors do not mention it, I think that Chandler 2005 spotted an L3d2 in Epipaleolithic Portugal (originally reported as "N"). However, using only the HVS region, the exact adscription is always somewhat dubious.

Also they performed an Structure analysis (fig. 4) and found that the carriers of the allegedly autochthonous European L lineages displayed very low to zero African affinity (and also near zero East Asian one) while those with the probably recent L lineages had more African and East Asian admixture (East Asian in this case is proxy for Native American most likely, indicating creole origin from America), although the apportions varied from individual to individual. The strength of this test can only be valid for very recent arrivals anyhow, otherwise the African autosomal genetics would be diluted beyond detection in a couple of centuries or so.

13 comments:

  1. Vary interesting! I've always doubt that all L lineages in Europe arrived at recent times.

    ReplyDelete
    Replies
    1. This comment has been removed by the author.

      Delete
    2. I agree with ᧞eandertalerin and Wagg.
      However, I think more research needs to be done on L1b1a6. Reason being, I am aware of an Irish woman with Irish and Spanish ancestry for countless generations with this haplogroup, as well as a man who declared Irish, Portuguese, and Grecian ancestry. So it is not West African only.

      Delete
  2. Replies
    1. This comment has been removed by the author.

      Delete
    2. Thanks for sharing the post. I think more research needs to be done on L1b1a6. Reason being, I am aware of an Irish woman with Irish and Spanish ancestry for countless generations with this haplogroup, as well as a man who declared Irish, Portuguese, and Grecian ancestry. So it is not West African only.

      Delete
    3. See also http://familyhistoryresearchbyjody.blogspot.com/2013/01/ancient-mitochondrial-dna.html

      Delete
    4. It would seem that after the 'Out of Africa' there were some lesse mini-OoA flows. You can't enclose the sea...

      Delete
  3. @ ᧞eandertalerin

    "Vary interesting! I've always doubt that all L lineages in Europe arrived at recent times."

    Same here.

    ReplyDelete
  4. Maju,

    In 23andMe, I have the following L relatives:

    L1b1a x 2 - German names
    L1c2a1b - German name (Northern European ancestry)

    L2a1 x 2 - Unknown
    L2a1 - German
    L2a1a/E1b1a - Unknown
    L2a1a1/I2a2 - Guyana/Ireland
    L2c2 - Multiple Region ancestry

    L3b1a1/E1b1b1a2* - Unknown
    L3f1b3 - Unknown
    L3e5/I1* - Unknown
    L3b1a - Unknown
    L3e2b - Cuba
    L3d1-5/R1b1b2a1a1d1* - Unknown
    L3k/E1b1a8a - Cape Verde

    My Father:
    L0a2/R1b1b2a1a - Unknown

    L1b1a - Unknown
    L1c2a1b - German name (Northern European ancestry)
    L1c2b1 - Unknown

    L2a1 x 2 - Unknown
    L2a1 - Irish
    L2a1 - German
    L2a1h - Unknown
    L2a1a1/I2a2 - Guyana/Ireland

    L3b/E1b1a7a3a - Unknown
    L3b/R1b1b2a1a2f - Unknown
    L3b1a1/E1b1b1a2* - Unknown
    L3b1a - Unknown
    L3d1-5/R1b1b2a1a1d1* - Unknown
    L3d1b/R1b1b2a1a1* x 2 - Cuba/Ireland
    L3e2a - Unknown
    L3e2b/I1* - Unknown
    L3k/E1b1a8a - Cape Verde

    My Mother:
    L0a1a - Unknown
    L0a2a1/R1b1b2a - Unknown

    L1b1a6/I1 - Unknown
    L1b1a - German name
    L1b1a/R1b1b2a1a1d1* - German
    L1c1d - Unknown
    L1c3a1a/E1b1a7a - Unknown
    L1c2a1b - German name (Northern European ancestry)

    L2a1 - Unknown
    L2a1/B1* - Unknown
    L2b1a3/I1* - Ireland/Italy
    L2a1a/E1b1a - Unknown
    L2a1/E1b1b1c1 - Unknown
    L2c2 - Multiple Region ancestry

    L3f1b3 - Unknown
    L3e2b1a/I1* - Unknown
    L3e5/I1* - Unknown

    L4b - Ireland/Jamaica

    ReplyDelete
    Replies
    1. What do you mean by "L relatives"? They are from many different lineages.

      Or just meaning that are all people of more or less European ancestry which have L(xM,N) mtDNA lineages?

      Delete
  5. @Maju,

    I mean that based on my 23andMe results, all the people above are blood/genetic relatives of mine, who happen to have mtDNA L lineages.

    I've reached out to all of these people, and am in contact with some, and some have decided not to engage, and so are "Unknown".
    As you know, I am 100% Irish, and of those I am in contact with, a number are 100% European, including one Irish person, and a few Germans and others with German names.

    Just a few more data points, that's all.

    ReplyDelete
  6. Important paper. Thanks for putting it up.

    ReplyDelete

Please, be reasonably respectful when making comments. I do not tolerate in particular sexism, racism nor homophobia. Personal attacks, manipulation and trolling are also very much unwelcome here.The author reserves the right to delete any abusive comment.

Preliminary comment moderation is... ON (sorry, too many trolls).