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View Full Version : Mapping out common Genetic Groups among clusters



BalkanKiwi
04-01-2021, 12:38 AM
This exercise came about from this comment (https://anthrogenica.com/showthread.php?22522-MyHeritage-new-region-update-has-been-released-post-your-new-results-here&p=761895&viewfull=1#post761895) by boilermeschew827:




Maybe I am asking something someone has already done and just haven't read through yet, but has anyone run the autocluster tool and compared those matches and their groupings for each relative cluster? Perhaps a weekend project for myself. I can already think of several clusters that I share no ethnicity or groupings with, even though we should have a RCA.

I mentioned in that thread I've had a quick look at a few Italian matches, but wanted to go one step further to a larger number of matches, and look at my Scandinavian clusters. I have a thread where I've discussed this already, but to summarise, I have a cluster of triangulated Scandinavian/Danish matches on my father's Polish side (validated due to a cousin from this side who also matches them).

I have a larger cluster of Norwegians also on my father's side which are a bit more clear cut.

I wanted to know if its possible to use Genetic Groups to identify a general region where a common shared ancestor may have originated from. I went through each matches results and chose only med-high confidence groups to include, and selected groups that other matches in that cluster also have (there is a chance of potential bias, however given the med-high groups are mostly the same for everyone, I think it isn't an issue here).

Below is an image of each match, with the % of Scandinavian and strongest Genetic Groups. Nine out of the 12 matches have Bergen as med-high confidence. If we want to go broader, as Bergen is a city within Vestland, we can include another 2 matches.

https://i.imgur.com/QZsbYKN.jpg

Conclusion - It could possibly be assumed we all share a common Norwegian ancestor who originated from Western Norway. This assumption is only as good as the data used to create these groups, however it looks like MH has done a reasonable job of Norway, Sweden and Finland in particular.

I attempted this approach with the Danish matches, however they haven't provided as clear cut of a picture. Even though Funen (Fyn) only appears twice, along with Central Region, the logical assumption is we possibly share a Danish ancestor from central Denmark. Both of the matches with Funen are predicted 3rd-5th cousins.

https://i.imgur.com/QbIRhUv.jpg

BalkanKiwi
04-02-2021, 02:47 AM
I realised I forgot to include two other matches. One is the daughter of one of the other matches (91% Scandinavian), and gets Denmark (Funen) and Denmark (Bornholm).

The other match also has 91% Scandinavian, and he also has the Denmark (Funen) group. All of these groups are medium-high confidence.

BalkanKiwi
05-04-2021, 02:24 AM
I've made a find, and would greatly appreciate some input from those who know more about Viking movement into the British Isles. I have a 2nd cousin who has just joined 23andMe, (his great grandparents are my direct paternal great grandparents).

On 23andMe he also matches a Dane/Norwegian who I've previously identified. At a 8cM threshold on MH, this Scandinavian match forms a separate Norwegian cluster along the same segment as the cluster in the first post. Some of the matches in the first cluster triangulate here at 8cM, however if I drop the triangulation threshold to 6cM, most of them triangulate.

In summary, there is a segment on chromosome 5 with a total of 14 Scandinavians who mostly triangulate (12 of whom identify as Norwegian, which is reflected in their results/Genetic Groups), one of these is Danish going by their Genetic Groups, and the other (who triangulates with the 2nd cousin) is majority Danish, however has some Norwegian lines in his tree. Out of interest, his Genetic Groups are:

Denmark, Sweden (Skåne) and Germany (Schleswig-Holstein), Norway and Germany #2, Denmark (Central Region)

I'm comfortable at this point concluding we all likely share a common Norwegian ancestor. Having this 2nd cousin appear raises some questions. In terms of our shared ancestry, on paper this is from Lincolnshire, Poland (Pomerania) and Sussex. To my knowledge and what I can find, the Danes generally occupied Lincolnshire, the Norsemen had no presence in southern England, and I don't believe (please correct me if wrong) Norsemen traded with or went on crusades of the Baltics like Sweden and Denmark did.

People moved around, and a paper trail clearly doesn't reflect movement that occurred in the Middle Ages. On the Eurogenes K13 this segment is majority Atlantic, and given the triangulation with a few majority British matches on 23andMe, I'll assume at this stage this Scandinavian input was through the British Isles. Where this occurred however, I'm not 100% sure.

The most logical explanation I currently have is possibly through the Lincolnshire line, via Scandinavian York (https://en.wikipedia.org/wiki/Scandinavian_York). Given the majority of the matches Genetic Groups are from Western Norway along the coast, it would make sense for Norsemen to launch from here into the eastern part of England/Scotland, and then move down into York during that period.