Wednesday, April 15, 2009

What you already knew about Finns   posted by Razib @ 4/15/2009 01:16:00 PM

Genetic markers and population history: Finland revisited:
The Finnish population in Northern Europe has been a target of extensive genetic studies during the last decades. The population is considered as a homogeneous isolate, well suited for gene mapping studies because of its reduced diversity and homogeneity. However, several studies have shown substantial differences between the eastern and western parts of the country, especially in the male-mediated Y chromosome. This divergence is evident in non-neutral genetic variation also and it is usually explained to stem from founder effects occurring in the settlement of eastern Finland as late as in the 16th century. Here, we have reassessed this population historical scenario using Y-chromosomal, mitochondrial and autosomal markers and geographical sampling covering entire Finland. The obtained results suggest substantial Scandinavian gene flow into south-western, but not into the eastern, Finland. Male-biased Scandinavian gene flow into the south-western parts of the country would plausibly explain the large inter-regional differences observed in the Y-chromosome, and the relative homogeneity in the mitochondrial and autosomal data. On the basis of these results, we suggest that the expression of 'Finnish Disease Heritage' illnesses, more common in the eastern/north-eastern Finland, stems from long-term drift, rather than from relatively recent founder effects.

The Wikipedia entry on Swedish-speaking Finns highlights the controversies about their origins. Some claim that they are Finns who switched to Swedish as they rose up the class hierarchy, while the alternative model is that they are the descendants of immigrants who arrived after the Swedish conquest of much of Finland during the 12th and 13th century. Additionally, there is the countervailing dynamic whereby it seems that many Swedish speaking Finns have been assimilated into the Finnish speaking population since the 19th century.

Of course it doesn't need to be a black-white dichotomy of immigrants vs. the indigenous. But the genetic data can help quantify the proportion of gene flow due to migration vs. acculturation. Right now the genetic data don't seem to support a strong version of the hypothesis that Swedish-speaking residents of Finland are simply the descendants of those who switched to the Swedish language. Rather, a non-trivial level of migration seems likely to have been an integral part of the process.

H/T Dienekes

Related: The genetics of Fenno-Scandinavia, Finns as European genetic outliers and Estonians are not like Finns.

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