Evidence map›Paper›PMID 42736576›Full record

ArticleGenome biology2026

Population genomics, demography, and circum-Baltic connectivity of Early Medieval southwestern Finland.

Ronan James O'Sullivan, Ulla Nordfors, Nelli-Johanna Saari, Kerttu Majander, Jussi-Pekka Taavitsainen, Kati Salo, Adam B Rohrlach, Elina Salmela, Thiseas C Lamnidis, Luca Traverso and 3 more

Abstract readHistorical Article
In one paragraph

Article in Genome biology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

13 authors.

Ronan James O'SullivanDepartment of Biology, University of Turku, Turku, Finland. ronan.osullivan@utu.fi.
Ulla NordforsDepartment of Biology, University of Turku, Turku, Finland.
Nelli-Johanna SaariGlobe Institute, University of Copenhagen, Copenhagen, Denmark.
Kerttu MajanderDepartment of Environmental Sciences, University of Basel, Basel, Switzerland.
Jussi-Pekka TaavitsainenDepartment of Archaeology, University of Turku, Turku, Finland.
Kati SaloDepartment of Archaeology, University of Helsinki, Helsinki, Finland.
Adam B RohrlachDepartment of Archaeogenetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.
Elina SalmelaDepartment of Biology, University of Turku, Turku, Finland.
Thiseas C LamnidisDepartment of Archaeogenetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.
Luca TraversoDepartment of Archaeogenetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.
Johannes KrauseDepartment of Archaeogenetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.
Sanni Peltola *Department of Biology, University of Turku, Turku, Finland.
Päivi Onkamo *Department of Biology, University of Turku, Turku, Finland.

Funding

Jane ja Aatos Erkon Säätiö 160003Research Council of Finland 352727
6 · The paper itself

Abstract

backgroundKnowledge of Early Medieval Finland (1050-1250 CE) relies primarily on archaeological evidence, as contemporary sources are scarce. The available evidence indicates two distinct cultural-economic zones: coastal and inland. Using newly generated genomic data from 34 ancient individuals alongside modern Finnish genomes, we characterise Late Iron Age and Early Medieval ancestry in southwestern Finland, reconstruct demographic patterns, and place individuals within a circum-Baltic relatedness network.

resultsEarly Medieval ancestry in inland southwestern Finland was very similar to that of present-day inhabitants. Ancient coastal and inland individuals were genetically indistinguishable, whereas modern coastal populations showed substantially more Scandinavian ancestry, and less Baltic ancestry compared to their ancient counterparts. IBD (identity-by-descent) analyses also indicate a major genetic shift in the coastal zone since the Early Medieval Period. Effective population size increased throughout the study period and was ~ 13,000 by 1250 CE. IBD links between Scandinavia and Early Medieval Finland align with known archaeological connections. Furthermore, we identify IBD links between individuals from Early Medieval Finland and victims of the Kronan warship sinking.

conclusionsWe demonstrate nearly a millenium of population continuity in the inland zone of southwestern Finland, contrasted by a large, contemporaneous genetic shift in the coastal zone. This ancestry shift corresponds with documented medieval emigration from Sweden to Finland. The regional population rapidly expanded during this time period, likely due to new agricultural practices and favourable climatic conditions. Our circum-Baltic IBD network indicates that southwestern Finland was firmly embedded into the wider, pre-modern Baltic world.

Indexed as

Genetics, PopulationMetagenomicsDemographyDNA, AncientFinlandGenome, HumanGenomicsHistory, MedievalHumansScandinavians and Nordic PeopleDNA, AncientAncient DNABioarchaeologyBiobankEarly Medieval FinlandFinlandGenetic shiftGotlandIBDIdentical-by-descentSweden

Identifiers

PMID42736576
PMCPMC13576218

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.