Tuesday, June 7, 2016

Interesting Genomes in Medieval North Africa (Gunther et al, 2016)

Quick snippet from a paper that will be presented this July at the Society for Molecular Biology and Evolution Conference 2016.  Thanks to Matt for posting at Eurogenes.

"The genomic enigma of two Medieval North Africans"

"Both individuals – which represent the first ancient genome sequence data from North Africa – do not exhibit particular genetic affinities to modern North Africans or any other present-day population in published genotype data sets despite relatively extensive data has been produced from many areas of Africa. In fact, the most parsimonious way to model them genetically is as two-source admixture between Mediterranean Europeans and Southern Africans."
Let me break this down.  Two medieval genomes of North Africa are not immediately akin to Berbers.  They appear to be a mixture of something Khoisan-like and something Southern Europe, Mediterranean-like.*

The authors interpret this in the most parsimonious way (at least from the abstract), that the Barbary-Moorish slave trade could have brought together these individuals' ancestries. 

"Both individuals could represent a Medieval African population without population continuity to modern-day populations"
This has the potential to get very interesting, very quick.
Tassili Round Head Period (Libya)
The original inhabitants of the Saharan Early Neolithic 'wet phase' are generally called 'Roundheads' after their abundant rock art.  These people inhabited a landscape and an ecology very similar to those of modern San-Khoisan peoples and their theorized ancient domains.  Given that fact, I'd expect these people to be more similar to Khoi people than to Pygmy or West African peoples.

Modern San-Khoisan also have Southern Europe (Mediterranean)* admixture somewhere between 14% or more and I'll link to some recent articles below.  The San-Khoisan element could be a substrate across much of the continent in addition to introgression from the Neolithic expansion, maybe in multiple places.

To put it directly, these Medieval individuals could be the remnants of native, North African ethnicities that were progressively destroyed in the Berber, and later Arab, expansions.  I'm not saying that will be the case, but I'm satisfied knowing something I had predicted, that when the first genomes of North Africa start coming in, they'll be diverse and look neither Berber or Arab.

Khoisan People [PBS]

There is also a new paper by Zvelibil et al 2016 that I have lost for the moment.  It proposes that ceramic pottery was independently invented in North Africa based on some very early sherds from Mali.  While I'm always very deeply skeptical of 'independently' this or that, I think the North African Neolithic will soon become a very interesting place.

See also from
Newscientist [Khoisan have Eurasian DNA]

and Phys.org
[Khoesian have West Eurasian admixture]

*I had mis-spoke and said South Mediterranean, which obviously doesn't make any sense in genetic terms.  The question will be if it is possible to sufficiently distinguish admixture between a modern and Neolithic sources


  1. They talk about "Mediterranean Europeans" not "South Mediterranean-like" (whatever it means!)

    1. Mediterranean like or Southern Europe is what I meant. Thanks for bringing to my attention

    2. This comment has been removed by the author.

  2. It's still a rather vague term, is it not? I mean, Sardinians, Iberians and South Italians are all Mediterranean Europeans, yet they differ quite a little bit.

    Interesting to know, nonetheless, North Africa has not been given enough focus yet. Looking foward to more!

    1. Yeah, to kind of clarify my response to your comment and Ariele, if you click on the hyperlink to the paper, there is some additional background. They explicitly rule out modern North African affinity and instead consider "Mediterranean Europeans and Southern Africans".
      I'm inferring this is basically something Neolithic or Sardinian and excludes additional admixture in Southern Europe. But again, I am reading between the lines. Hopefully the paper will make the genome public when it is released.

  3. "The San-Khoisan element could be a substrate across much of the continent"

    I'm surprised this hasn't had more attention as it seems potentially pretty fundamental.

    If Bantu expansion then
    - what was there before?

    If before was Khoisan-like then
    - how far north did it extend?

    I was looking at this a while ago - i forget the reason - and there was (until 1991) a tribe reportedly Khoisan-like in what going by their name (worm eaters) sounds like the most unpleasant part of the Libyan desert (which might be why they survived i guess).


    I wonder if they would match these samples?

    Very interesting indeed.

    1. Interesting group of people, especially given their original location. Thanks for sharing