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Angela
10-09-14, 22:43
Another upcoming ancient DNA paper.

Insights into British and European population history from ancient DNA sequencing of Iron Age and Anglo-Saxon samples from Hinxton, England. S. Schiffels, W. Haak, B. Llamas, E. Popescu, L. Loe, R. Clarke, A. Lyons, P. Paajanen, D. Sayer, R. Mortimer, C. Tyler-Smith, A. Cooper, R. Durbin.

British population history is shaped by a complex series of repeated immigration periods and associated changes in population structure. It is an open question however, to what extent each of these changes is reflected in the genetic ancestry of the current British population. Here we use ancient DNA sequencing to help address that question. We present whole genome sequences generated from five individuals that were found in archaeological excavations at the Wellcome Trust Genome Campus near Cambridge (UK), two of which are dated to around 2,000 years before present (Iron Age), and three to around 1,300 years before present (Anglo-Saxon period). Good preservation status allowed us to generate one high coverage sequence (12x) from an Iron Age individual, and four low coverage sequences (1x-4x) from the other samples. By providing the first ancient whole genome sequences from Britain, we get a unique picture of the ancestral populations in Britain before and after the Anglo-Saxon immigrations. We use modern genetic reference panels such as the 1000 Genomes Project to examine the relationship of these ancient samples with present day population genetic data. Results from principal component analysis suggest that all samples fall consistently within the broader Northern European context, which is also consistent with mtDNA haplogroups. In addition, we obtain a finer structural genetic classification from rare genetic variants and haplotype based methods such as FineStructure. Reflecting more recent genetic ancestry, results from these methods suggest significant differences between the Iron Age and the Anglo-Saxon period samples when compared to other European samples. We find in particular that while the Anglo-Saxon samples resemble more closely the modern British population than the earlier samples, the Iron Age samples share more low frequency variation than the later ones with present day samples from southern Europe, in particular Spain (1000GP IBS). In addition the Anglo-Saxon period samples appear to share a stronger older component with Finnish (1000GP FIN) individuals. Our findings help characterize the ancestral European populations involved in major European migration movements into Britain in the last 2,000 years and thus provide more insights into the genetic history of people in northern Europe.

One thought occurs to me immediately...How many French genomes are included in the 1000 genomes compilation? I think this is important given prior studies that saw affinities between S.W.English samples and those from France.

Aberdeen
11-09-14, 02:41
This should be interesting.

It looks as if the summer drought of DNA papers is over.

motzart
11-09-14, 03:10
This is the most exciting paper for me... ever! I would guess the Iron Age individuals are Romans which is why they bear a Spanish affinity. For the Anglo-Saxons bearing a Finnish affinity....... could our Anglo Saxons be Y DNA I !? I hope so. I would be so thrilled if either were an I2a1c!

Angela
11-09-14, 05:10
This is the most exciting paper for me... ever! I would guess the Iron Age individuals are Romans which is why they bear a Spanish affinity. For the Anglo-Saxons bearing a Finnish affinity....... could our Anglo Saxons be Y DNA I !? I hope so. I would be so thrilled if either were an I2a1c!

I would doubt that they chose a sample from a Roman context. They seem to be trying to map out the difference between the Britons and the newly arriving Anglo-Saxons.

kamani
11-09-14, 05:11
So the current Brits are mostly Nordic Anglo-Saxons and the old Celtic Brits were Southern Europeans?

Angela
11-09-14, 05:22
So the current Brits are mostly Nordic Anglo-Saxons and the old Celtic Brits were Southern Europeans?

This is what they say in the abstract:
Results from principal component analysis suggest that all samples fall consistently within the broader Northern European context, which is also consistent with mtDNA haplogroups.

So, both are broadly within the Northern European cluster, but the "Briton" population may plot further south. We'll have to wait for the paper to see the details. If the comparison data contained French samples, that might have been a closer match.

If I were going to guess wildly, perhaps the Anglo-Saxon group had more hunter gatherer, more ANE and less EEF than the "Briton" group?

Interesting times for genetics research indeed.

sparkey
11-09-14, 07:07
Very excited about this one. I'm guessing that the references to Spain and Finland are basically indications that the Britons will be more Atlantic, while the Anglo-Saxon period people will be more North European, sort of like the Eurogenes clustering.

bicicleur
11-09-14, 08:39
This is the most exciting paper for me... ever! I would guess the Iron Age individuals are Romans which is why they bear a Spanish affinity. For the Anglo-Saxons bearing a Finnish affinity....... could our Anglo Saxons be Y DNA I !? I hope so. I would be so thrilled if either were an I2a1c!

My guess :
- iron age are R1b-L21 mixed with some late La Tene arrivals (Parisi, Belgae) mainly R1b U152 , all descendants of Unétice R1b-P312, hence the affinity with the nothern half of Iberia.
- anglo-saxon are Germanic tribes R1b-U106, I1, I2a2-CTS616, some R1a hence affinity with Scandinavia and Germany

The introduction tells nothing one could allready guess. Let's await the details.

Sile
11-09-14, 08:39
Very excited about this one. I'm guessing that the references to Spain and Finland are basically indications that the Britons will be more Atlantic, while the Anglo-Saxon period people will be more North European, sort of like the Eurogenes clustering.

the plotting is again useless in the article especially when discussing Spain, they still do not split Castile from Catalonia from Galicia. I see little point in placing all Spain together and trying to get some sense in this

Maciamo
11-09-14, 09:12
This is great news. One of the things that got me interested in population genetics many years ago was the possibility of assessing the percentage of Germanic vs Celtic vs Roman admixtures in Western European countries. As a Belgian, I was particularly interested in fine-scale variations within Belgium, but the story of the Anglo-Saxon then Viking invasion of Britain has also fascinated me too.

It's interesting and odd at the same time that the relatively pure Anglo-Saxon genomes tested should be closer to the modern Finns than to the northern Dutch, Saxons or Danes. This presupposes a high percentage of I1, yet English people carry much more R1b-S21 than I1 like the Dutch.

Also surprising that British Celts from the Late Iron Age should be closer to modern Spaniards than to Bretons or Welsh. Or perhaps did they fail to compare the new samples to the Welsh and Breton populations, which would be incomprehensible for this kind of study.

Sile
11-09-14, 09:33
This is great news. One of the things that got me interested in population genetics many years ago was the possibility of assessing the percentage of Germanic vs Celtic vs Roman admixtures in Western European countries. As a Belgian, I was particularly interested in fine-scale variations within Belgium, but the story of the Anglo-Saxon then Viking invasion of Britain has also fascinated me too.

It's interesting and odd at the same time that the relatively pure Anglo-Saxon genomes tested should be closer to the modern Finns than to the northern Dutch, Saxons or Danes. This presupposes a high percentage of I1, yet English people carry much more R1b-S21 than I1 like the Dutch.

Also surprising that British Celts from the Late Iron Age should be closer to modern Spaniards than to Bretons or Welsh. Or perhaps did they fail to compare the new samples to the Welsh and Breton populations, which would be incomprehensible for this kind of study.

tacticus stated that the aestii spoke the same as the britons ..............was he right?

Aberdeen
11-09-14, 15:35
Perhaps if the Y haplotype I1 material arrived mainly with the Anglo-Saxons, along with the R1a, that would be sufficient to give the appearance that Anglo-Saxons tilt toward Finns, whose second largest Y haplotype after N is I. The appearance of pre-Anglo-Saxon Celts in England tilting more toward Spaniards probably just has to do with R1b being as dominant among the Celts in England of 2000 years ago as it currently is in Wales and Ireland.

Aaron1981
11-09-14, 15:39
It's interesting and odd at the same time that the relatively pure Anglo-Saxon genomes tested should be closer to the modern Finns than to the northern Dutch, Saxons or Danes. This presupposes a high percentage of I1, yet English people carry much more R1b-S21 than I1 like the Dutch.


Actually this is exactly what the study did NOT say. It stated the Anglo-Saxon burial was closest to modern British samples, who are in turn closest to Dutch and Irish samples. They are not by any means closest to modern Finns.

gyms
11-09-14, 15:51
In addition the Anglo-Saxon period samples appear to share a stronger older component with Finnish (1000GP FIN) individuals.

Sile
11-09-14, 20:03
In addition the Anglo-Saxon period samples appear to share a stronger older component with Finnish (1000GP FIN) individuals.

anglo-saxon period does not mean specifically anglo-saxon people.......it means in the time when the anglo-saxons where there...............the anglo-saxons did not replace the entire indigenous populace.

bicicleur
11-09-14, 20:47
anglo-saxon period does not mean specifically anglo-saxon people.......it means in the time when the anglo-saxons where there...............the anglo-saxons did not replace the entire indigenous populace.

we should await the actual paper, it is not at all clear what is meant here

motzart
12-09-14, 01:42
I would doubt that they chose a sample from a Roman context. They seem to be trying to map out the difference between the Britons and the newly arriving Anglo-Saxons.

2000 ybp is Roman Era Britain though and Cambridge is right in the heart of it, neither do they say explicitly from what group the iron age people came from.

Angela
12-09-14, 02:15
Obviously, we'll have to wait for the details, but the stated purpose of the paper is to examine the "repeated immigration periods and associated changes in population structure." The context is the Anglo-Saxon migrations of the early medieval period. In order to sort that out, they would obviously want to use ancient dna from a Briton and some Anglo-Saxons.

Given all of that, I would think that the researchers would have been very careful not to choose a sample from an archaeologically ambiguous context, but we'll see when the paper comes out.

More importantly, a "Roman" would not plot as a "Northern European".

From the abstract: Results from principal component analysis suggest that all samples fall consistently within the broader Northern European context, which is also consistent with mtDNA haplogroups.

Of course, even if the sample is from a "native" site, I suppose there's no absolute guarantee that there wasn't some admixture from some "Roman" from more southern parts of the empire.

JS Bach
12-09-14, 06:37
In the Eurogenes K15 breakdown table, they have a “SouthEast English” sample that breaks down as being 35.52% “North Sea” and 29.86% “Atlantic.” From the table, the “North Sea” component peaks among West Norwegians and the “Atlantic” component peaks among French Basques. I hope to see how these two components will differ among these new ancient samples. As a Canadian of mostly English descent, I’ll certainly be looking forward to the paper. My percentages are 34.08% “North Sea” and 28.20% “Atlantic.”