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View Full Version : A Y Chromosome analysis of the British Isles/Genetic Structure British Population.



JohnHowellsTyrfro
01-06-2018, 09:31 PM
I'm not sure whether people are familiar with this paper which is some years old but maybe contains some interesting data :-
"Conclusions
The detailed sampling scheme used here identified other previously unknown regional patterns in the degree of continental input. For example, the Central-Eastern part of England experienced the most continental introgression. In addition, our inclusion of samples from Wales additional to those of Weale et al. [7] indicates that the transition between England and Wales is somewhat gradual, which was not visible in the samples analyzed in the Weale et al. study

Most studies in human evolution and genetic history have used samples from very few locations, often near major metropolitan areas. Here, we show that detailed samples from multiple small, urban areas with a geographically structured sampling design reveal patterns that could not be detected with typical sampling schemes. For example, analyses of multiple sets have confirmed higher continental input in central England and the northernmost samples (Durness, on the north coast of Scotland and the Scottish Isles) and a lower level of continental introgression in southern England and Lowland Scotland. In addition, multiple sample sets revealed heterogeneity in Wales.

Iberian, French, and Central-Northern Italian populations have been shown to have similar Y chromosome compositions, presumably reflecting their common heritage in the European Palaeolithic [14]; Wilson et al. [4] noted that AMH+1 haplotypes at high frequency are associated with the European Palaeolithic. Here, we note that another haplogroup (I1b2) is found almost exclusively in British populations that have experienced little or no continental genetic input (Tables 1 and S1). Intriguingly, earlier studies have shown that it is present in the Iberian Peninsula at low frequencies (0%–5.4%) and in Sardinia at a significant percentage (35.1%) [9, 14]. This group might be another constituent of the European Palaeolithic.

Finally, we note that forensic analyses based on the Y chromosome generally assume homogeneity of Y chromosome haplotypes throughout most of Europe [17]. Our fine-scale investigation of Y chromosome variation demonstrates appreciable frequency differences of Y chromosome haplotypes over relatively short geographic distances. Haplotype 12 13 11 16 25 11 (hg R1a1) (number of repeats, loci as follows: DYS388, 393, 392, 19, 390, 391) is present at frequencies around 5% in Shetland and Orkney, while it is almost completely absent from the other collections. Similarly, haplotype 14 13 11 14 22 10 (hg IxI1b2) was recorded at 6%–7% in the Central-East English samples, but it was absent from Irish, Welsh, and Scottish populations."

http://dx.doi.org/10.1016/S0960-9822(03)00373-7


This reference is included in another paper on the fine scale genetic structure of the British population:-

"This reveals a rich and detailed pattern of genetic differentiation with remarkable concordance between genetic clusters and geography. The regional genetic differentiation and differing patterns of shared ancestry with 6,209 individuals from across Europe carry clear signals of historical demographic events. We estimate the genetic contribution to southeastern England from Anglo-Saxon migrations to be under half, and identify the regions not carrying genetic material from these migrations. We suggest significant pre-Roman but post-Mesolithic movement into southeastern England from continental Europe, and show that in non-Saxon parts of the United Kingdom, there exist genetically differentiated subgroups rather than a general ‘Celtic’ population."

https://www.nature.com/articles/nature14230

JohnHowellsTyrfro
01-07-2018, 06:47 AM
" With regard to source populations, we note that Weale et al. [7] recently used Friesland as an Anglo-Saxon representative source population and suggested a substantial replacement of pre-Anglo-Saxon paternal lineages in central England. We therefore compared Frisians to our North German/Danish sample and found that the two sets are not significantly different from each other (p = 0.3, data not shown). When included in the PC analysis, the Frisians were more “Continental” than any of the British samples, although they were somewhat closer to the British ones than the North German/Denmark sample. For example, the part of mainland Britain that has the most Continental input is Central England, but even here the AMH+1 frequency, not below 44% (Southwell), is higher than the 35% observed in the Frisians. These results demonstrate that even with the choice of Frisians as a source for the Anglo-Saxons, there is a clear indication of a continuing indigenous component in the English paternal genetic makeup."

Pascal C
01-07-2018, 06:56 AM
" With regard to source populations, we note that Weale et al. [7] recently used Friesland as an Anglo-Saxon representative source population and suggested a substantial replacement of pre-Anglo-Saxon paternal lineages in central England. We therefore compared Frisians to our North German/Danish sample and found that the two sets are not significantly different from each other (p = 0.3, data not shown). When included in the PC analysis, the Frisians were more “Continental” than any of the British samples, although they were somewhat closer to the British ones than the North German/Denmark sample. For example, the part of mainland Britain that has the most Continental input is Central England, but even here the AMH+1 frequency, not below 44% (Southwell), is higher than the 35% observed in the Frisians. These results demonstrate that even with the choice of Frisians as a source for the Anglo-Saxons, there is a clear indication of a continuing indigenous component in the English paternal genetic makeup."

Wasn't that 2002 or something. AMH1, the sign of the iberian refuge

JohnHowellsTyrfro
01-07-2018, 07:04 AM
Wasn't that 2002 or something. AMH1, the sign of the iberian refuge

Yes 2003.

Pascal C
01-07-2018, 07:19 AM
Sorry, I'm tired tried reading through some weeks of posts on things. So, why post this?

JohnHowellsTyrfro
01-07-2018, 07:39 AM
Sorry, I'm tired tried reading through some weeks of posts on things. So, why post this?

The more recent article is from "Nature" 2015 and includes references and links to other studies.
I thought some of the content and data may be new to some people. I was also interested in whether people had any thoughts (agree or disagree) with the conclusions.
Don't worry reading and commenting isn't compulsory if of no interest. :)

Pascal C
01-07-2018, 07:53 AM
The more recent article is from "Nature" 2015 and includes references and links to other studies.
I thought some of the content and data may be new to some people. I was also interested in whether people had any thoughts (agree or disagree) with the conclusions.
Don't worry reading and commenting isn't compulsory if of no interest. :)

No I haven't been on the site since it was down so I've been trying to catch up. Okay I missed the 2015 but Weale IIRC was based on just 3 areas and resulted in some ridiculously extraplotive, (is it a word?) and speculative conclusions. There was a wipe out across Britain except for Wales.

JohnHowellsTyrfro
01-07-2018, 09:00 AM
No I haven't been on the site since it was down so I've been trying to catch up. Okay I missed the 2015 but Weale IIRC was based on just 3 areas and resulted in some ridiculously extraplotive, (is it a word?) and speculative conclusions. There was a wipe out across Britain except for Wales.

I'm no expert on the technical data but I think a number of studies suggest there may be something distinctive about Wales compared with other regions of Britain although of course it does seem there are differences within Wales too.
Perhaps the recent Irish studies shed further light.
The Romans, Anglo Saxons and Normans it seems had a relatively low or no impact on Wales partly because of reasons of geography and accessibility. Possibly this applied to some extent to earlier migrations too at least in the more remote parts of Wales?.
The Welsh language still exists whereas it has mostly disappeared elsewhere in Britain.

Pascal C
01-07-2018, 09:16 AM
Well you kind of lost me on the lack of impact in Wales by Normans

JohnHowellsTyrfro
01-07-2018, 10:37 AM
Well you kind of lost me on the lack of impact in Wales by Normans

I think where there was conquest of Wales actual settlement was more confined to the accessible parts like around the coasts and the borders. The numbers of the "invaders" it seems weren't great anyway. You could argue maybe it was more containment of certain areas than occupation and settlement.
As you know the central parts of Wales are mostly upland with dispersed settlement until comparatively recent times. Not a lot other than minerals to attract concentrated settlement from outside.
I'm not suggesting there was no genetic impact, just that it may have been minimal in more isolated areas?