Millions of people have taken DNA tests. Many have taken them not as much to connect with DNA relatives but to find out their ethnic origins. However, this is still a relatively new and developing field. Any ethnicity results now are expected to change as the science improves. They are not expected to be 100% correct right now. Earlier I wrote in DNA Testing, What Do My Origin Percentages Mean? that most geneticists believe ethnicity through DNA can be defined at the continent level pretty well, but not as well within a continent.
One of those smaller, sub-continent regions in DNA ethnicity estimates is Scandinavia. Scandinavia generally includes Norway, Sweden, and Denmark. Many people with British ancestry see Scandinavian ancestry in their DNA origin results. Ancestry blogs has an article AncestryDNA – The Viking in the room. This article showing the genetic Scandinavian ancestry distribution across Great Britain and Ireland (specifically the average percent predicted Scandinavian), which peaks around the East Midlands at 13.5%. The article shows two major migrations that involved Scandinavians settling in Great Britain, the Anglo-Saxon migration around 400 AD and the Danish Viking migration starting in 876 AD. These help explain the Scandinavian component of Great British DNA. But remember to be cautious. DNA tests are still just giving estimates of British versus Scandinavian DNA.
Recently I received the DNA results for two family members who are Scandinavian. One is Norwegian, with all great-grandparents from Norway. The other is Swedish, with all great-grandparents from Sweden. One would guess that they both would be around 100% Scandinavian. Here are their origin results, as reported by FamilyTreeDNA:
- Scandinavia 55%
- British Isles 29%
- Finland and Northern Siberia 14%
- Eastern Middle East 2%
- 87% Scandinavia
- 8% Finland and Northern Siberia
- 2% Central Asia
- 1% Southern Europe
- 1% Northeast Asia
The first interesting result is the “British Isles” component of the Norwegian’s DNA. Noted above, history records migration from Scandinavia to the British Isles, but not significant migration the other way. It is more likely some of his distant cousins from Scandinavia settled in Great Britain, and are considered “British Isles.” Perhaps part of the “British Isles” origin as it is defined now is in fact still significantly “Scandinavian.” The Swedish individual shows none of this British Isles component. Likely people from the current-day Norwegian area would have had better access to Great Britian than the Swedish.
Both individuals have a Finland and Northern Siberia component. The Norwegian individual is from a more Northern area, so it makes sense that that person would have a more significant contribution from Finland and Northern Siberia.
The Swedish individual has a Southern Europe component, which according to the write-up from FamilyTreeDNA includes some of the settlers of Sweden, which were generally replaced. The Norwegian individual had no component from this area.
Both individuals have additional contributions from areas outside of Europe. The Norwegian from Eastern Middle East, around Jordan. The Swedish individual from Central Asia, around Afghanistan, and Northeast Asia, a large area including Japan and the area north of Afghanistan. Since geneticists believe we can distinguish DNA signatures between continents pretty well, it is likely there is something to these results from far-off lands. This map shows the extent of Viking Expansion. The Scandinavians traveled to many areas around Europe and even further. It is reasonable to think that people from some of those places could have contributed to their DNA.
Of course as the models and algorithms improve, these numbers are expected to change. But it is interesting to see how a person who has all great-grandparents from the same area of Norway or Sweden could have diverse, non-Scandinavian results. Perhaps testing more Norwegian individuals would help better distinguish Scandinavian versus British Isles origins. I am particularly interested to see how future integration of ancient DNA in the algorithms may affect these results.
UPDATE: FamilyTreeDNA released the next revision of DNA origin estimates on April 6, 2017. The changes are discussed in Revised Ethnic Origins at FamilyTreeDNA.