“The main finding of this study is that despite Norway’s long maritime history and as a former Danish territory, the region closest to mainland Europe in the south appears to have been an isolated region in Norway, highlighting the open sea as a barrier to gene flow into Norway.”
Mattingsdal, M., Ebenesersdóttir, S.S., Moore, K.H.S. et al. The genetic structure of Norway. Eur J Hum Genet 29, 1710–1718 (2021). https://doi.org/10.1038/s41431-021-00899-6