The Finnish population is one of the most genetically studied in the world. A relatively small number of founder individuals and strong genetic isolation over centuries have shaped the unique genetic makeup across the country that we are now utilizing heavily in genetic studies of diseases and traits. Here, we present a fine-scale genetic structure of Finland before 1950s, thus focusing on the time before large-scale migrations and urbanization that have occurred since 1950s. These results are published and explained in more detail in G3: Genes, Genomes, Genetics.
Check also a special stamp that uses these population genetic results to celebrate the first 100 years of independence of Finland.
Data and Methods: Data are from the FINRISK Study of the National Institute for Health and Welfare and contain 1,042 individuals whose both parents were born under 80 km from each other. No pairs of close relatives were included. Additionally, genetic data from 230,000 positions of the genome was utilized. Computational methods used were ChromoPainter and FineSTRUCTURE.
Maps: Each point represents one individual and is located at the mean coordinates of the parents’ birthplaces. We show 17 maps that divide the individuals into groups based on genome information and shown by separate colors. The first map presents only one group and at each subsequent step one of the groups splits into two subgroups. The interpretation is that, on each map, the individuals in one group are on average more genetically similar with each other than with the individuals from the other groups. We expect that the order of splits has an approximate correspondence to the amount of genetic differentiation between the groups and the tree on the right hand side of the map shows the relationships of the groups measured by a genetic distance.
Below the maps you can study the structure at a specific level and compare the groups to the dialectal regions of the Finnish language.
Reuse: Figures can be reused under the license CC-BY 4.0.
Contact: Matti Pirinen (supervision) and Sini Kerminen (analyses).
Organizations: Institute for Molecular Medicine Finland (FIMM), University of Helsinki and the National Institute for Health and Welfare.
Funding: University of Helsinki and the Academy of Finland.
1,042 Finns located at the mean of their parents' birthplaces. Samples cover Finland evenly except for Lapland in the North, with only a few individuals, and the islands of Åland with no individuals at all.
1,042 Finns located at the mean of their parents' birthplaces. Samples cover Finland evenly except for Lapland in the North, with only a few individuals, and the islands of Åland with no individuals at all.
The main genetic division splits Finland into an eastern (blue) and a western (red) part separated by a border line drawn from the southeastern corner of Finland to the western coast near the city of Oulu, and continuing northeast leaving the western Lapland closer to the western genetic group. This split has similarities with the medieval border of the treaty of Nöteborg from 1300s, with the settlement history of Finland and with the dialectal regions of the Finnish language.
For more information, see our publication and the description of a Finnish stamp including this east-west genetic pattern.
The main genetic division splits Finland into an eastern (blue) and a western (red) part separated by a border line drawn from the southeastern corner of Finland to the western coast near the city of Oulu, and continuing northeast leaving the western Lapland closer to the western genetic group. This split has similarities with the medieval border of the treaty of Nöteborg from 1300s, with the settlement history of Finland and with the dialectal regions of the Finnish language.
For more information, see our publication and the description of a Finnish stamp including this east-west genetic pattern.
East population is split into a northern subgroup (cyan), that includes Kainuu and Northern Ostrobothnia, and a southern subgroup (blue), that includes Central Finland, Savonia and Karelia.
East population is split into a northern subgroup (cyan), that includes Kainuu and Northern Ostrobothnia, and a southern subgroup (blue), that includes Central Finland, Savonia and Karelia.
Now also the western population is split into northern (black) and southern (red) subgroups.
These first three splits show that the Finnish population is first divided along the east-west direction and then along the north-south direction resulting into four geographically motivated populations.
Now also the western population is split into northern (black) and southern (red) subgroups.
These first three splits show that the Finnish population is first divided along the east-west direction and then along the north-south direction resulting into four geographically motivated populations.
We observe a population (yellow) that is more scattered across the country than any other population we have identified. This population includes individuals near the southern cities of Helsinki and Vyborg (located in Russia) and extends along the genetic east-west borderline all the way to Oulu. These individuals are 8 years younger on average than the individuals in the other populations, indicating that their ancestors have had more time to move around the country. The youngest third of these individuals could in principle be grandchildren of almost 400,000 Karelians who were relocated from the larger Karelia region southeast of the borders of Finland throughout the remaining parts of Finland during and after the second world war 1939-1945. However, this major relocation event cannot explain completely the spread of the yellow population since we see that the spreading had already started before the war. (See publication for more details.)
We observe a population (yellow) that is more scattered across the country than any other population we have identified. This population includes individuals near the southern cities of Helsinki and Vyborg (located in Russia) and extends along the genetic east-west borderline all the way to Oulu. These individuals are 8 years younger on average than the individuals in the other populations, indicating that their ancestors have had more time to move around the country. The youngest third of these individuals could in principle be grandchildren of almost 400,000 Karelians who were relocated from the larger Karelia region southeast of the borders of Finland throughout the remaining parts of Finland during and after the second world war 1939-1945. However, this major relocation event cannot explain completely the spread of the yellow population since we see that the spreading had already started before the war. (See publication for more details.)
A geographically clustered population (green) in South Ostrobothnia splits from the southwestern Finland (red).
A geographically clustered population (green) in South Ostrobothnia splits from the southwestern Finland (red).
This split separates Kainuu (pink) and North Ostrobothnia (cyan).
This split separates Kainuu (pink) and North Ostrobothnia (cyan).
North Ostrobothnia is further divided into the light green population covering Kuusamo, an internal genetic isolate in Finland, and the cyan population closer to the west coast.
North Ostrobothnia is further divided into the light green population covering Kuusamo, an internal genetic isolate in Finland, and the cyan population closer to the west coast.
Population in South Ostrobothnia divides into a northern (rose) and southern (green) part. Comparison with the dialectal regions (click the button "Show dialectal regions") shows that the northern population is interestingly located on the narrow peak of the Savonian dialect that extends west to Ostrobothnia.
Population in South Ostrobothnia divides into a northern (rose) and southern (green) part. Comparison with the dialectal regions (click the button "Show dialectal regions") shows that the northern population is interestingly located on the narrow peak of the Savonian dialect that extends west to Ostrobothnia.
Lapland in the north separates from the individuals on the coast of Ostrobothnia.
Lapland in the north separates from the individuals on the coast of Ostrobothnia.
More structure is revealed in the Kainuu region.
More structure is revealed in the Kainuu region.
A population (dark purple) that extends from Kymenlaakso on the south coast to Central Finland splits from the scattered eastern group (yellow).
A population (dark purple) that extends from Kymenlaakso on the south coast to Central Finland splits from the scattered eastern group (yellow).
A north-south split within Savonia-Karelia region.
A north-south split within Savonia-Karelia region.
Western Savonia (orange) emerges.
Western Savonia (orange) emerges.
North Savonia (white) and North Karelia (blue) emerge.
North Savonia (white) and North Karelia (blue) emerge.
Southwest corner of Finland splits into eastern (skyblue) and western (red) parts.
Southwest corner of Finland splits into eastern (skyblue) and western (red) parts.
The last split happens in the southwest part of Finland where historical Southwest Finland (red) separates from Pirkanmaa (golden).
The last split happens in the southwest part of Finland where historical Southwest Finland (red) separates from Pirkanmaa (golden).