The genetic map of Britain

By Razib Khan | July 9, 2012 11:38 pm

Update: A commenter noted that North England and Southwest Wales have different shape points. This is clear in the original PDF when I increased resolution. So ignore my comment about Brythonic Celtcs.

End Update

A few weeks ago I heard about the project to create a genetic map of Britain. Actually, I knew a bit about this because they’ve been publishing a few papers here and there over the years. But there is now an an exhibit up at The Royal Society Summer Science Exhibition 2012. My attention was drawn to this because British tabloids kept pushing headlines like “Cornish genetically different from other English!” I emailed one of the scientists associated with the project, Peter Donnelly, but he never got back to me. So I figured I would post anyway. Looks like they’re using thousands of samples at 600,000 SNPs. When they get a paper out it should be neat. On the other hand the map leaves a little to be desired. The clusters are clear, but what’s the genetic distance between the clusters in a relative sense? How were the cut-offs devised? I’m sure there are reasonable answers, but it’s all rather opaque at this point.

Nevertheless, I do want to point out two things. First, Anglo-Saxon England rather jumps out at you does it not? Second, the similarity between southwest Wales and northern England is explicable. The northern English region was associated with the Brythonic Celtic kingdom of Rheged, and later the southern portion of historical Strathclyde. These were the cousins of the Welsh, not Gaels like the Scots, but Britons. This is evident in the name Cumbria, it has the same root as Cymry, the ethnonym of the Welsh for themselves.

MORE ABOUT: British Genetics

Comments (18)

  1. Xris

    A colour key would be very useful here.

  2. Interesting that the Danelaw *doesn’t* show up. Danes too similar to the Anglo-Saxons?

    It would be fascinating to compare this with Anglo-Americans and see if Albion’s Seed is upheld on a genetic level (although the book was about cultural entities, not necessarily genetic).

  3. Naughtius Maximus

    There is actually a conference/exhibit on around this time where they are going into more detail.
    It also seems raw data may be made available.

  4. Karl Zimmerman

    I’m not so certain there is a link between Wales and North England.

    Looking at the TIFF, the orange markers in SW Wales are all circles. All the orange markers in Northern England, in contrast, are squares. Most markers are squares, but there are also cicles in the Orkneys, as well as triangles. The question is, what do the shapes versus colors signify? I suppose colors could relate along one PC, and shapes along another. Their mapping software may just have run out of standard colors, however, and started using shapes for clusters.

    Also, it’s odd the remote corners of Wales have so many samples, but virtually no one comes from Cardiff or the Welsh coal valleys. Perhaps they realized there would be significant admixture there, and skipped the area?

    Scotland (outside of the Orkenys) and Northern Ireland seem to have very few samples. This seems to indicate there is no genetic difference between Lowlanders/Highlanders in Scotland, and none between Ulsterman and Irish in Northern Ireland, but given how spotty the data is in these areas, it’s hard to say for certain. It makes sense, given known history, that Ulstermen would cluster as Scots, but if Irish Catholics in Ulster do as well, it suggests that Ireland may not have merely introduced Gaelic just before recorded history, but largely ethnically replaced the Picts and whatever other Brythonic and/or non Indo-European groups were in Alba.

  5. Kaviani

    This is very bare bones- even the link has nothing but very generic talk about face shapes, surnames, and self-promotion. Also, a sampling of only 2,000 seems…ambitious given the scope of their goal.

  6. Bobby LaVesh

    @2 Mike,

    Absolutely, that was the first thing I noticed too… Wonder what they’re looking at to determine the “squares”- what DNA they looked at? If we’re looking at mitochondrial dna we probably wouldn’t see any Danelaw evidence as the women were not brought over in large numbers.

    Otherwise it is strange the Danes arn’t showing up in the North- unless they were indistinguishable from the Angles, Saxons and Jutes in this test.

  7. Ron Strong

    2 and 6

    It depends on whether the Danelaw represented merely an elite replacement or a full scale migration of a peoples displacing those who had been there previousl (largely anglo-saxons).

    If the numbers coming from Scandinavia and Scandinavian populated areas in other parts of the british isles were relatively small they would have had a comparatively small impact on the genetic makeup of inhabitants of north-east england.

    Danelaw lasted a relatively brief time. Insufficient for a small favored founding population to gradually outbreed the existing anglo-saxons.

  8. Obviously, the huge 700 ft wall of ice that divides the North from the South would have a big impact on gene frequencies. The folk north of the wall have more ancestry from the “First Men.” I think I read that somewhere.

  9. Raimo Kangasniemi

    Danelaw area probably didn’t even mean total elite replacement, even on the male side; there’s enough sporadic evidence of high-ranking Anglo-Saxon collaborators to show that. On the other hand, that a lot of Scandinavian place names took root and have survived to this day shows a rather significant, lasting impact on some level – whether that included genetic is an another thing. Scandinavian first names also survived centuries in a limited use on the area.

    I don’t see a good reason to avoid Cardiff or the or other parts of Wales now lacking from the data; these areas were still heavily Welsh speaking in the 1891 census and just selecting for example people whose all grand-parents were from these areas should have been to some extent an effective way of closing out the most recent waves of immigration.

  10. john morgan

    Correction to my last post. The map shows the Orkney Islands rather than the Shetlands, but these were also settled by Norway.

  11. alan

    really kicks out at the established point of view that the Cornish don,t exist it is only a very few years that the Cornish language has been allow in to existence the claim that every thing Cornish is made up does not hold a lot of scientific water how does it.

  12. Amanda S

    The distribution of the green squares in the north east of England (with some in the north west) suggests a population influenced by Scandinavian settlement. The question is why this influence isn’t showing up further to the south. My understanding is that Danes would be very close genetically to Angles and Saxons but that Norwegians would be detectably different. Maybe certain parts of Denmark had people who were different enough from Angles and Saxons to cluster in a different way and these people settled where the green squares show up.

    The Danish invasion was definitely not just an elite invasion. As Raimo noted, if you look at the place names in the north of England (the fell and dale area), it’s quite easy to pick out the large number of settlement names of Scandinavian origin. Also lots of surnames from the north of England (and Scotland) have a Scandinavian origin.

    What will be helpful in interpreting the map is when we get to see the maps that connect this information to the rest of north west Europe and to the republic of Ireland as shown in this blog post.

    I believe that the researchers have restricted themselves to people of rural origin, avoiding the cities. It would be good if they had samples from every non metropolitan county particularly more samples from Scotland.

  13. If the numbers coming from Scandinavia and Scandinavian populated areas in other parts of the british isles were relatively small they would have had a comparatively small impact on the genetic makeup of inhabitants of north-east england.

    The place name Ingoldsby in Lincolnshire has been interpreted as meaning “English village”, suggesting that there were enough Danes in some districts that an Anglo-saxon village was noteworthy (-by typically indicates a Scandinavian settlement).

  14. Dwight E. Howell

    The Angles, Saxons, Jutes, Franks, and Danes are all pretty close and the borders shifted more than a bit. Wonder how the Frisians fit in? My data suggests this tribe was in place before the Roman conquest.

  15. The map that is shown on the Royal Society’s website and here is not the same one that was displayed in the exhibition. The one in the exhibition showed more clusters. As far as I can recall North Wales and Orkney were completely separate clusters. The researchers understandably don’t want to publish all their detailed maps before the paper is published but the paper will contain all the different maps at the different levels of clustering. For those people who are members of ISOGG ( – membership is free) we have some close-ups of the maps in our Facebook group:

    At the Ancient Britons in Cardiff we were also told that the researchers found genetic differences within Cornwall with the people in the far west of Cornwall forming a separate cluster. This does not show up on any of the maps I’ve seen so far.

  16. alan

    It is understandable that their may well be differences with in Cornwall the west having more connection with Europe and the North with Ireland and Wales .a study of Cornish history and in particular names in place names such as saints and the tre ,pol, and pen names which of course means a knowledge of the Cornish Language can give an easy guide to this fact any Cornish student will know very early on where a place name as come from

  17. Amanda S

    I found this map of Scandinavian settlement names in England.

    It doesn’t accord with my green square theory because County Durham, Tyne and Wear and southern Northumberland are the areas where there are lots of green squares but, according to the linked map, they contain few Scandinavian settlement names. The heavy area for these spans from North Yorkshire southwards to Leicestershire.


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About Razib Khan

I have degrees in biology and biochemistry, a passion for genetics, history, and philosophy, and shrimp is my favorite food. In relation to nationality I'm a American Northwesterner, in politics I'm a reactionary, and as for religion I have none (I'm an atheist). If you want to know more, see the links at


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