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Tuesday, September 4, 2018

Viking Age diversity

Four of the ancient Scandinavians from the recent Krzewinska et al. paper on the Viking Age town of Sigtuna made it into my Global25 and North Europe Principal Component Analyses (PCA). Click on the images below to view the hi-res versions of the plots. The relevant datasheets are available here and here. I've also updated all of the main Global25 datasheets with these samples. See here and here.

They cover a lot of ground between them, don't they? Sigtuna_84005 probably has ancestry from what is now Finland, because he's pulling sharply to the east and overlapping with a western Finn. He also belongs to Y-haplogroup I1a1b3 or I-Z74, which is very common nowadays in western Finland.

The fact that Sigtuna_grt036 is overlapping strongly with Germans suggests that he has ancestry from the southern Baltic region, and indeed his Y-hg I2a2 gels rather nicely with this idea. I don't know what to make of Sigtuna_grt035's occidental affinities, but his Y-hg G2a2 is also somewhat unusual for the Baltic region. Interestingly, Sigtuna_stg021 is a female and the only really obvious Scandinavian in this group, but that might be a coincidence.

As far as I know, nothing suggests that any of these males were captives or slaves. So we must assume that they were either migrants or the recent descendants of migrants who settled in Sigtuna for one reason or another, and may even be the ancestors of the Swedes living in the region today.

See also...

Global25 workshop 3: genes vs geography in Northern Europe

Genetic and linguistic structure across space and time in Northern Europe

Modeling genetic ancestry with Davidski: step by step


EastPole said...

From the way these Swedish Vikings were admixed we can conclude that they raided West Slavic and East Slavic/Baltic/Ugro-Finnic areas:

Norwegian Vikings were probably raided Celtic and Germanic lands and were shifted towards these populations.

Wastrel said...

Worth pointing out that 'slaves' in the Viking context weren't just a handful of people kept in cages - they were the foundation of society. In some areas around a third of the population was enslaved - and it could be more than that in colonised areas (and Sigtuna may be in Sweden, but apparently it was only founded in the 10th century). What's more, slaves could be freed, or buy their freedom, and in that case they were generally adopted into the family of their former owner - so even among non-slave families you'd expect to see a degree of slave genes.

This seems more likely, in any case, than non-Vikings migrating there, since those non-Vikings would pretty much immediately become slaves if they did so.

AWood said...

I guess if 'diversity' is determined by grown men walking 200 miles in a southern-like direction to continental Europe, then's 'diverse'.
Has anyone looked at the rest of the data? The mass grave dating suggests they were some of, or were the earliest inhabitants. The founding of the town was by pagans but at some point becomes Christian.

Janko Raven Johnson said...

Though Sigtuna (as opposed to Fornsigtuna) appears to have been founded or re-founded in the 970s (right around the time the previously preeminent trading center Birka was destroyed), wasn't it closely connected to burgeoning church/state power, eliminating out of carolingian/ottonian Europe? Also, aren't some of the samples from a much later medieval context? It may not therefore be surprising that some of the samples bear southerly affinities.

Slumbery said...

"The fact that Sigtuna_grt036 is overlapping strongly with Germans suggests that he has ancestry from the southern Baltic region, and indeed his Y-hg I2a2 gels rather nicely with this idea."

I don't know, this North-Central European PCA is not very good at picturing the south-north axis, but Signuta_grt036 is placed among modern Hungarians (and close Slavs and southern Germanics), so he is probably more Southern than just the southern Baltic.

weure said...

In the northern PCA my father and I plot close to sigtuna 21 in the Global 25 draw closer to sigtuna35, how come?



Davidski said...


Because the two PCA focus on different things, and the North Euro PCA is purposely skewed more by ethnic-specific drift, especially Baltic, Slavic and Finnic.

Theo Deric said...

It is not possible to conclude from the report that these individuals were Swedish Vikings. Sigtuna was one of Northern Europe's most important trading posts at the time and these individuals could just aswell have been either slaves or merchants. You would need DNA from the villages along the Mälaren Valley if you want a more accurate approximation of the genetic composition of the Swedish Vikings, even though they probably had some foreign slaves there aswell. Also, most of these individuals appear to have been Christians, while the Swedish Vikings were generally pagans. That said, it is higely likely that there is some Slavic/Finnic/British admixture in parts of the Swedish Viking population, but we'll need more data to be sure of that.

Davidski said...

I've got the Rakhigarhi ancient DNA blog post written up and ready to roll. ;)

Ric Hern said...

At long last.....Heheheeeh

EastPole said...

“I've got the Rakhigarhi ancient DNA blog post written up and ready to roll. ;)”

Did you get the samples to analyze or is it based on articles in Indian press and other sources?
If you analyzed the data does it confirm what we already know and what Razib was writing about or there are some new discoveries?

Davidski said...


Nope, don't get too excited, it's basically just one paragraph and you'll see it very soon.

Mikkel Nørtoft said...

Am I right in reading individual urm160 with R1b1a(1a)2a1a1 (R-L11) as being on the R1b-U106 branch like much earlier Lille Beddinge in South Sweden 2275-2032 BCE?

(generally it seems to me that lineages earlier written R1b1a1a2 are now often written R1b1a2. Anyone up for explaining this?)

Mikkel Nørtoft said...

Well ain't that curious.

In the main article, urm160 is R1b1a2a1a1 but R1b1a1a2a1 in the supplementary table.

What's going on?

Matt said...

Dropping the Sigtuna individuals onto a tree of fairly West Eurasian pop averages:

(They're about half way up, marked in black).

It looks like they all:

A) Sit on the same part of the tree as Nordic_IA.
B) Form a bridge between NW European part of the tree and samples enriched in WHG leading up to Loschbour, e.g. CWC_Baltic, but lacking any apparent strong specific Baltic-Slavic / Finnic connection.

Despite long branches, they all sit close to Nordic_IA and CWC_Baltic, and they don't "hop about" on the tree, such that one is closest to English average, one to Finnish/Estonian, etc.

Caution is that they all have long branches, so I am a bit curious about if they have any data quality issues.

Comparison trees:

1) Same as above with no Sigtuna samples: Nordic_IA here is just a long branch with Sweden within the NW European part of the tree, with no special position relative to WHG.

2) With average of Swedish Viking Age, but without individual Sigtuna samples: Nordic_IA + Swedish_Viking_Age form a clade which sits next to present day Swedish average, within the NW European clade.

3) With individual Sigtuna samples, but without average of Swedish Viking Age: All the samples other than grt035 sit together and forming a bridge between CWC_Baltic and Nordic_IA (which connects to present day Sweden). grt035 seems like a "generic" EBA/LBA North-Central European here, but with a long branch.

Perhaps Sigtuna samples, or at least 84005 and stg021 (the evidence seems more equivocal for the average, and the other two samples) have quite enriched WHG relative to present day without Baltic-Slavic / Finnic specific drift?

jan.t.andersson said...

I hope noone draws conclusions about the Swedish population from a few graves in Sigtuna in the 10th-11th centuries. It would be something like drawing conclusions about today's Swedes by examining Stockholm's diplomatic community.

truth said...

One of them plots with Hungarians, he's either central-european or a mix of Swedish and something more southern

Davidski said...


I'm quite sure that 84005 has Finnish ancestry. But whether he's from western Finland or just has significant Finnish admixture is another issue. If he was alive today I'd probably say he was a Finland Swede.

I don't know if any of these samples actually have Baltic or Slavic ancestry, but grt036 could well be from what is now Germany, while grt035 might be of mixed Scandinavian/Celtic origin.

The female, stg021, just looks very Scandinavian to me.

So I don't think your cluster analysis contradicts any of that, nor does the idea that some of these individuals might be seriously enriched for WHG or SHG ancestry make me reconsider my conclusions. In fact, the average positions of these four samples in both of my PCA are very close to Nordic_IA.

Davidski said...


grt036 plots consistently with northeast Germans, and in the North Euro PCA with Hungarians who clearly have Germanic/West Slavic ancestry.

EastPole said...

To get something German, Swedish Vikings would have to go around Jutland Peninsula; seems quite far. Slavs and Balts were closer:

Arza said...

Results based on full North Europe PCA:

Komi:komi1 22.4%
Irish:Ireland13 17.6%
Welzin_BA:WEZ58 13.8%
Finnish:HG00276 8.4%
Welzin_BA:WEZ24 8%
Welzin_BA:WEZ61 7.6%
CWC_Czech:I7280 7.6%
Yamnaya_Samara:I0357 7%
Srubnaya:I0422 5.6%
Yamnaya_Kalmykia:RISE240 2%

Scottish:Scotland4 41.2%
England_Roman:6DT23 19.2%
Welzin_BA:WEZ39 9.0%
Baltic_BA:Turlojiske1932 7.0%
German:IL550_0031 6.0%
Beaker_Central_Europe:I5524 5.4%
Scottish:Scottish1 5.0%
Beaker_Central_Europe:I7211 2.4%
Hungarian:hungary13 1.6%
Irish:Ireland15 1.6%
German:IL550_0271 0.8%
Danish:Denmark1 0.4%
Estonian:ee1 0.4%

Belarusian:belorus7 36.4%
Welzin_BA:WEZ74 18.6%
Yamnaya_Ukraine:I3141 11.4%
Irish:Ireland11 11.2%
Scottish:Scottish4 6.6%
Welzin_BA_outlier1:WEZ54 6.4%
Irish:Ireland23 4.4%
Beaker_Central_Europe:I7251 2.4%
Czech:CzechR1 2.2%
Polish:Polish6 0.4%

Irish:Ireland8 45.6%
Potapovka:I0419 21.6%
Poltavka:I0440 15%
Beaker_Britain:I1770 9.4%
Germany_Medieval:STR_486 6.8%
Hungarian:hungary11 0.8%
Scottish:Scottish4 0.6%
Welzin_BA_outlier1:WEZ54 0.2%

Steppe_MLBA/EMBA population living in Ukraine almost as late as the common era?

We detect no significant contribution of the Scythians to the Early Iron Age Ponto-Caspian gene pool, inferring instead a genetic continuity in the western Eurasian Steppe that persisted from at least 4,800–4,400 cal BP to 2,700–2,100 cal BP (based on our radiocarbon dated samples), i.e. from the Yamnaya through the Scythian period.

Shaikorth said...

@Matt, Davidski
84005 has Finnic-looking drift based on Eurogenes K36 too. However doesn't look like it's modern Finnish-like since this sample doesn't show the Saami ancestry modern Western Finns or Finland-Swedes do. I'd say he's either from Estonia or from a very early stage of Finnic settlement in Finland when Saamis weren't yet assimilated (based on a ISBA 2018 abstract that might be just a few centuries before the man lived).

nMonte3 on scaled global25 data (pen=0)




Matt said...

@Davidski, you're definitely right that there are ways that the sample 84005 is Finnish like, on the ANE-WHG dimension and also the Balto-Slavic like dimension (and I probably overstated by saying that 84005 lacks Finnic / Balto-Slavic specific admixture). But still would say looks to me to be well outside the Finnish range on for'ex East Eurasian related drift that Finns have, looks no more than present day average Northern Europeans and not intermediate Finns (Finnish general or Finnish_East) and present day Swedes/Nordic_IA.

Example, look at PC3 of this PCA on PCA based on G25: Maybe that's more the reason that sample tends to neighbour join with the CWC_Baltic average rather than Finnish or Finnish East. The samples definitely seem like nearest neighbours of each other as well, other than grt035. But I'm not gonna be dogmatic on it.

Matt said...

@Shaikorth, yeah, that sounds plausible to me.

Davidski said...

Seems like in the paper 84005 shows higher affinity to Estonians, Lithuanians and southern Finns than to Northwestern Europeans in the f3 outgroup stats.

Matt said...

Taking their supplementary data all the ancient Sigtuna samples show pretty high affinity to Lithuanians, and to a lesser extent Estonians. Lithuanian particularly is the #1, #2, or #3 ranked for all ancients. That follows the general pattern in outgroup f3 stats where lots of populations have Lithuanian as their number 1 f3 coalescent, even if the pop is closer to others considering f2, fst, global 25 distance. (And a similar thing can be true considering Sardinians and EEF rich populations).

But you're certainly right that 84005 has a relative bump for Lithuanians, Estonian, Finn. FinnishFIN specifically is relatively high to 84005, though there is not a grade shift in f3 like there is between NW European and Lithuanian and FinnishFIN more or less overlaps with NW European in f3 to 84005.

Extracted the data from the supplement if anyone interested in plots and rankings here:

Shaikorth said...

Srkz from molgen did a short IBD/Haplotype run for 84001 and stg021 (these seem mostly Scandinavian-like on a PCA or K36).
I plotted the results against each other:

IBD or haplotype data from the other samples would probably be very informative regarding their relation to modern populations. So would rare alleles for that matter, and in fact there are rare allele results in the supplements but they appear to be almost unreadable.

dsjm1 said...

Blogger Mikkel Nørtoft said...
Am I right in reading individual urm160 with R1b1a(1a)2a1a1 (R-L11) as being on the R1b-U106 branch like much earlier Lille Beddinge in South Sweden 2275-2032 BCE?

(generally it seems to me that lineages earlier written R1b1a1a2 are now often written R1b1a2. Anyone up for explaining this?)

What I can point out is how 4 years ago I tried to show people in my project the contradictions emerging in the naming of Haplogroups. I gave up using the long form after this because I no longer trusted it or how people might use it.

Doug M