h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

There has been some interesting research published on the DNA of Britain.

http://www.telegraph.co.uk/news/science/science-news/11480732/Britons-still-live-in-Anglo-Saxon-tribal-kingdoms-Oxford-University-finds.html

With respect to Devon, we are a distinct group, separate from Cornwall but also different from Dorset and the rest of a uniform central/southern England.

This is not 'new' news, as this information was published in 2012.

What is new is the analysis of how the seventeen different genotypes in the UK vary from each other, and where the genotypes come from.

Typically, 'ancient briton' dominates throughout. However, the findings include the discovery that Welsh, Scottish and Cornish DNA are not very similar.

Devon and Cornwall share many similar characteristics in their 'traditional' DNA, but there are subtle differences.

The problem with the data obtained from this study is that it mostly consists of Autosomal DNA statistics. Due to the process of recombination, Autosomal DNA changes from generation to generation, unlike the Y-Chromosome and mtDNA which change very little from one generation to the next down the family tree. Therefore, if there was little in the way of interbreeding between Devonians and Cornish in the last century or so, then there would be distinct differences between Devonians and Cornish as far as Autosomal DNA is concerned.

Other studies conducted by Sykes and Oppenheimer confined their analyses to Y-Chromosome and mtDNA, and concluded that there was very little difference between Devonians and Cornish in terms of early ancestral origins dating back thousands of years. Their studies concluded that about 78.2% of Devonians and Cornish could trace their direct line male and female ancestry to post Ice Age migrations from Northern Iberia, and in this respect they were similar to the current populations of North Wales (78.5%), Scottish Borders (78.1%), and Tayside (78.9%). Incidentally, these Y-Chromosome studies show that even in East Anglia, the majority of males (51.2%) are also of Northern Iberian (post Ice Age) ancestry.

PlymExile,

The original research report in 2012 simply grouped the population into similar genotypes. As such, it simply indicated that the populations were "different" without explaning why (or how).

The 2015 appears to use the same base data, but has further analysed the differences, and attempted to link the groups to different sources (on the basis that the UK was not populated at the height of the last major iceage).

I have a full copy of the "nature" article, including appendices, if anyone is interested.

This gives some information on how the study analysed the data, including how "different" each of the 17 populations are, and where those genotypes came from.

The summary is that Orkney is the most "different" area (because of its clear viking DNA component), with the 3 Welsh populations the second most obvious group.

One headline finding is that there is no consistency between the traditional "celtic" areas - namely Scotland, Wales and Cornwall. In fact Scotland and Cornwall are much closer to the main "South/Central/Eastern England" region than Wales.

Cornwall was relatively close to the main English region, and very clise to the typical DNA of Devon. Devon is more distinct from England than the West Yorkshire group (Elmet), and almost as distinct as the Welsh border group. Cornwall is slightly more distant from these groups, but not that different.

Devon and Cornwall have a higher "iberian" component than the main English group, and a lower anglo-saxon component.

In fact, both Devon and Cornwall have the lowest prportion of GER6 (which is thought to be the main Anglo-saxon element) of anywhere in the UK.

However, we have slightly higher proportions of GER3 (which originates in eastern Germany) which might relect Neolithic movements.

The "French" origin is much higher in Devon/Cornwall than the main English group, but not as high as Wales.

Where do Devon and Cornwall differ? Devon DNA has slightly higher GER3 (eastern German),Danish (DEN18) and Swedish (SWE121 sources than Cornwall, but these are relatively small differences.

What is interesting to me is that the Devon DNA boundaries very clisely match Devon's borders. In fact this is particularly true in the east- with a few outliers in western Somerset. Despite the media reports I don't see the Tamar boundary as being that clear. There are a number of Devonian DNA signatures in eastern Cornwall, with the boundary being more obvious west of Bidmin moor.

Ozzie Exile,
A closer analysis of the data seems to indicate that the Y-Chromosome distribution was not even considered, as all previous population genetic studies revealed large (majority) Y-DNA imports to Britain from the Basque region of Northern Iberia, yet in the current analysis, no DNA from this area is even indicated. The only indicated input from Iberia is from the Catalonia region (SFS31), which is very small in volume throughout Britain.

Even in France, no input from Brittany is recorded, the nearest being from Normandy (FRA14). Yet again, other analyses report a strong correlation in Y-DNA between Brittany and the Celtic regions of Britain (including Devon).

The apparent inconsistency between the Celtic regions yet again seems to suggest that Y-DNA has not been included in the equation. Perhaps it has been omitted as it represents only a small percentage of the total genome, but this ignores its importance in being one of only two parts of the genome which change very little down the direct ancestral line, and therefore provides a much better indicator of ancestral origins than Autosomal DNA.

Even the (GER6) component almost certainly gives an exaggerated value of the level of 5th/6th century Anglo-Saxon settlement/invasion throughout England, as there are no evaluations of the dates of these incursions, unlike the Oppenheimer analysis which shows that a large majority of this input occurred long before the Roman period.

Although (as you state), the Swedish (SWE121) input is slightly higher in Devon than in Cornwall, the Swedish (SWE117) input in Cornwall is slightly higher than that in Devon, but both are fairly negligible in magnitude throughout Britain.

As far as the Devon borders are concerned, a few crossovers do occur both to the west and east, as one might expect if there was some local inter-breeding, but it is quite clear from the overall picture that there is a clear difference between Devon and Central/Southern England, which is backed up by the Y-DNA analyses performed by both Oppenheimer and Sykes, showing (78.2%) R1b in Devon and Cornwall, as opposed to only (57.7%) R1b in the South of England.

Plymexile,

Breton DNA is anattractive idea for further research

Given the history of migration FROM Devon and Cornwall TO Brittany in the 3rd to 6th century, it would be interesting to see how the DNA of various parts of Brittany compares, especially as different parts of Brittany were linked to Devon and Cornwall (e.g. Domnonee and Cornouialle).

On another tack, I have seen some criticism of the recent DNA research because it did not make comparison with DNA from burial sites from the dark ages and before.

Ozzie Exile

I have found some Y-Chromosome DNA figures for Brittany, which make interesting reading.

The main Y-Haplogroup components are:-

R1b (from Northern Iberia/Basque region): 80% (Some of the Breton R1b could be “second hand” from Devon/Cornwall).
I (from Northwest Germany/Denmark): 13.5%
R1a (from Norway): 0.5%

These compare with Devon/Cornwall components (source - Sykes):-

R1b: 78.2%
I: 12.6%
R1a: 4.2%

It seems that there is a problem in obtaining valid DNA data from early burial sites, due to contamination. However geneticists have been able to obtain valid mtDNA samples from skeletal teeth. In this way it was established by Bryan Sykes that the mtDNA of 'Cheddar Man' (dated to 7150BC), whose skeletal remains were found in Gough's Cave, Cheddar Gorge, was identical to mtDNA extracted from two current residents of Cheddar, and is still commonly found among the British people.

Plym Exile,

Thank you for the information. Interesting!

To my untrained eye, the Breton results appear in very similar proportion to the Devon/Cornwall numbers, except for the latter have the relatively small R1a input from Norway.

Does this R1a signal reflect a small, but noticeable influx of "viking" settlers into Devon/Cornwall after the sixth century?

What is also surprising to me is that the I reading, which Is from Denmark/North Germany, is much the same both sides of the Western Approaches, especially if you correct for the minor dilution by Norse genes. Where is the impact from Anglo-Saxon settlement? Did Brittany have an equivalent influx from Normandy to match that of Devon/Cornwall?

Ozzie Exile,

With regard to the small R1a influx into Devon/Cornwall, it is known that Norwegian Vikings sailed down the Irish Sea with settlements in the Isle of Man and Ireland (near Dublin), so it is likely that a few of them got as far as Devon/Cornwall and settled there.

According to Sykes, the I input to England as a whole was 22.2%, but both Sykes and Oppenheimer, using haplotype dating techniques concluded that most of that input occurred a thousand or more years before the 5th/6th century Anglo-Saxon settlements, which only accounted for about one fifth of the I haplogroup currently found in English men as a whole, and probably less than that in Devon/Cornwall.

You are probably correct in thinking that at least some of the 13.5% I component found in Breton men is due to influx from Normandy, though even here the R1b component forms the large majority.