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The story of the African A1 lineage found in Yorkshire is not as simple as we thought

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  • The story of the African A1 lineage found in Yorkshire is not as simple as we thought

    [Note: I used samples from ysearch.org to investigate what I wrote below, so this may be particularly interesting for some ftdna members.]

    In 2007 a genetic survey of England found a very weird haplogroup in a man from Yorkshire. It was A1a (back then it was known as A1), which is found mainly in West Africa. The geneticists compared the haplotype of the Yorkshire A1a with A1a samples from Guinea-Bissau, Niger, and an African American and concluded that, though it wasn't very typical of sub-Saharan A1a, it was close enough to connect it to a historic origin from Africa. The study can be found here (it's freely available):



    When the geneticists studied A1a they had access to 11 samples. But the world of human genetics is exploding. I found 23 haplotypes, and with this new information I have grouped the A1a samples into 3 clusters:

    [See attached image at end of post: A1a-haplotypetable.gif]

    The following graph neatly illustrates the cluster membership by showing the genetic distances between the clusters. Note that the graph claims to show the distance from the modals of each cluster but it actually shows the distance from the average values of each cluster.

    [See attached image at end of post: A1a-geneticdistancesbetweenclusters.gif]

    I was very thorough about eliminating related samples and making sure that any samples I predicted as belonging to A1a really did belong to A1a. I seriously doubt I made a mistake, but of course, it's not impossible. There are only 2 samples that have an exact 12-marker match, but they're from Belgium and England, plus one was self-reported via Family Tree DNA and the other was submitted to yhrd.org, so it probably came from a genetic survey. Also, 12-marker matches aren't uncommon amongst unrelated people belonging to the same haplogroup. 2 samples came from the same city, Leuven, Belgium, but their genetic distance is one of the largest of any 2 samples in the Yorkshire cluster, and since they originate from yhrd.org, they probably came from a scientific survey, and scientific surveys try to ensure none of their testees are related.

    Regarding their geographic origin, the Yorkshire cluster is found in England, Belgium, and Niger (I think it's possible the Niger samples actually came from Mali, but it's not too important), the Sahel cluster is found in Guinea-Bissau, Senegal and Niger (another Niger sample from the same population as the previous one), and the West Africa cluster doesn't have any samples that can be located indisputably because they were all reported in people born in the US. But on account of the fact that 2 of these samples came from African Americans and that the other 4 are more likely than not to come from African Americans, I am presuming this cluster corresponds to the rest of West Africa.

    [See attached image at end of post: A1a-geographicrangeEurope.gif]

    [See attached image at end of post: A1a-geographicrangeAfrica.gif]

    There would seem to be 2 samples that don't fit. There's a European American belonging to the Sahel cluster and a Nigeri (not Nigerian) belonging to the Yorkshire cluster. I have a theory how this could have come about. The highest percentage of A1a is in the Guinean region. All these samples belong to the Sahel cluster and they have by far the highest diversity of the 3 clusters. I think this is where A1a originated, with the Sahel modal. It diffused eastwards into the rest of West Africa, where it transmuted into the West Africa modal. It also diffused northwards to North Africa and Europe. The presence of an A1a of the Sahel cluster in a European American would be due to this ancient diffusion. The A1a in North Africa then transmuted into the Yorkshire modal and then spread into Europe and the Sahara. This would explain the weird distribution of the Yorkshire cluster, found in Northwest Europe and the southern part of the Sahara. To settle this mistery, we need to haplotype the known A1a samples from Morocco. There's also 3 A samples from Portugal and the Azores, and an apparent A sample from Germany. But a supposed A(xA3b2) from South Tyrol (Italy) almost certainly belongs to J and was misreported.

    Due to the lack of representation of the central region of the range of A1a in the 2007 study, their discovery of a close match between the Yorkshire A1a and the Nigeri A1a was inevitably interpreted as representing a historic diffusion of A1a from Africa to Europe. There was already a slight hint that things were amiss when they stated that: "Although the British haplotype is peripheral, it lies equidistant (four mutational steps) from Niger and Guinea-Bissau haplotypes". Given the limited samples they had to work with, they reached the correct conclusion. The true mistake was not including A1a samples from a middle region like North Africa. But they knew about the A1a in Morocco, so if they didn't test them it's probably because the samples had already been destroyed.

    I also have a comment about the very curious distribution of the Yorkshire A1a, found on either side of the English Channel, but it's very controversial. As I've noted several times before, I don't believe one comma about the whole TMRCA theory, and I think almost all haplogroups have existed for tens of thousands of years. The Yorkshire A1a would have been scattered across the dry land between England and Holland, and the end of the Ice Age split its distribution into 2 camps on either side of the English Channel. In fact, the reason I started looking into A1a is because of my post a few weeks ago posing a challenge to believers of the TMRCA theory. In order to counter the responses I got to that post, I needed to find STR data on some very exotic haplogroups, such as A1, D2, or E1a. As I should have expected, I became fascinated in trying to decypher the haplogroups' composition and got completely sidetracked. And I'm still not done, because I also found some very interesting things about A3b2, E1a, and E2, and I'm going to write about them and post that later on.
    Attached Files

  • #2
    Sorry if this should already be evident but ...

    Sorry if I should have noticed this in the extensive material presented, but exactly how many independent haplogroup A lines have been observed with ties to Yorkshire?

    I just don't see how a single isolated instance of A in Yorkshire would require an elaborate ancient migration to explain.

    Yorkshire contained the industrial 18th and 19th century powerhouses of Leeds an Sheffield, and is so close to the world-class harbour of Liverpool.

    Why would anyone be shocked to see a single A here?

    I'd be a little more surprised to see it in Co. Kerry, but not at all in Yorkshire.

    Again, I apologise if the info is already presented, but it's packed rather densely. How many independent A lines are we talking about?

    Thanks.

    Jack

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    • #3
      When I click on the attachments I get a blank page. Does this happen to anyone else?

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      • #4
        Originally posted by Clochaire
        Sorry if I should have noticed this in the extensive material presented, but exactly how many independent haplogroup A lines have been observed with ties to Yorkshire?
        2 in England, 3 in Belgium, and 1 in Niger.

        I just don't see how a single isolated instance of A in Yorkshire would require an elaborate ancient migration to explain.
        This is part of something that I have been looking into for 2 years now. I have a very controversial view regarding haplogroups: I think that geneticists are very wrong about the validity of TMRCA and that virtually all haplogroups have existed for tens of thousands of years. I'm always looking for evidence to prove this, and this matter of A1a is yet another piece in the puzzle. So it's not like I thought up the ancient migration just to explain A1a.

        Yorkshire contained the industrial 18th and 19th century powerhouses of Leeds an Sheffield, and is so close to the world-class harbour of Liverpool.

        Why would anyone be shocked to see a single A here?

        I'd be a little more surprised to see it in Co. Kerry, but not at all in Yorkshire.
        It's not simply an A, but a specific subgroup called A1a which is found at 3% in the Guinean region of Africa, and a fraction of 1% in West Africa, North Africa, and Portugal. West Africa is 80% E1b1a and North Africa is 50% E1b1b1b. We know these 2 haplogroups are extremely rare in England and Belgium, so this puts a very low ceiling on any potential historic African ancestry in Northwest Europe. The bottomline is that it goes against all odds that we would find 5 independent cases of A1a in Northwest Europe due to a historic cause. But not due to a prehistoric cause.

        Also, I'm not the first to state that the presence of haplogroup A in Europe is so disproportionately high that there must be some prehistoric or Neolithic explanation to its presence, as oposed to a historic one. The authors of a 2005 study of Portugal also thought its presence was hugely disproportionate and raised the possibility it might have reached Portugal in an ancient migration, and not as a byproduct of history.

        Again, I apologise if the info is already presented, but it's packed rather densely. How many independent A lines are we talking about?

        Thanks.

        Jack
        No problem. It's 5 lines from England and Belgium, plus the Nigeri.

        Comment


        • #5
          Here's another detail I just thought of. If we try to explain this as the result of Moorish soldiers used by the Romans, which is the explanation cited by the original authors of the 'A1 in Yorkshire' study, we run into the following problem.

          According to the historic explanation, the A1a needs to trace back to a person who makes up only a small minority of the ancestry of English people: a Roman soldier. But not just any Roman soldier but a Moorish Roman soldier. And who wasn't just any Roman Moorish soldier but a Roman Moorish soldier who had the extremely exotic haplogroup A1a, found in only 0.4% of North Africans.

          And not just any Roman Moorish soldier who had the extremely exotic haplogroup A1a found in only 0.4% of North Africans, but also one who had many children that were amongst the small minority of Belgians or English that crossed the English Channel and settled on the other side in the last 2,000 years. And the Anglo-Saxons don't count because they were never occupied by the Roman soldiers!
          Last edited by argiedude; 9 August 2008, 02:43 PM.

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          • #6
            Originally posted by argiedude
            2 in England, 3 in Belgium, and 1 in Niger....

            ...No problem. It's 5 lines from England and Belgium, plus the Nigeri.
            Thanks. Any chance that contributors for Yorkshire samples are North Americans of English descent?

            The reason I ask is because I have seen a few problems with home-county assignments reported by North Americans in Irish Y projects, so I am curious.

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            • #7
              4 samples were taken in people living in England, Belgium, and Niger. The other 2 are self-reported and indicate ancestry in Belgium and England (they could be born in Europe or the US).

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              • #8
                A1

                I posted this in another thread but will also post here the Bass DNA project at FTDNA, about 1/2 are Hg A. From VA and NC.

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                • #9
                  Soooo... are you going to post some stuff about them later on or... was that it?

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                  • #10
                    A1

                    Originally posted by argiedude
                    Soooo... are you going to post some stuff about them later on or... was that it?
                    I was letting you know it was there. If interested contact the group administrator. The results are public under the Bass surname project since you are studing A1 Hg .

                    Search all forums, acticles or FamilyTreeMaker trees on Genealogy.com


                    Here is a link to some information on this line in genforum

                    Comment


                    • #11
                      I was looking at this post on dienekes's blog:
                      nso' in cameroon

                      This family is stated as YxBR,A3b2. So this seems to leave A1, A2, A3b1. Given that they are in Cameroon, one would think A1 (which has nothing to do with hunter-gatherers. nor with pygmies). Does anybody have any idea of what they are?

                      (and of course, why didn't the authors test the specific A subgroup?)

                      cacio

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                      • #12
                        Maybe the A1 is from a vacation in the Bahamas/Bermuda. If it were me, along with genealogy, I'd try to find out where and when each generation went on vacation/traveled.

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