Ringed seals in Fennoscandia – inhabiting the Baltic Sea and the lakes Saimaa and Ladoga – have long been considered descendants of a single colonization event following the Last Glacial Maximum (LGM). However, new analyses of 246 mitogenomes and 180 skulls reveal a far more complex history. The results suggest that the Saimaa and Ladoga seals originate from Arctic populations but became isolated earlier than previously thought and may be the result of multiple independent colonization events. The seals in Lake Saimaa, and to some extent in Lake Ladoga, have lost genetic diversity and developed distinct cranial morphology, whereas ringed seals in the Baltic Sea have retained high genetic and morphological variation. The study supports the recognition of the three populations as separate taxa and highlights the need for targeted conservation efforts considering climate change and human impact.

Find the full article by following the link: https://onlinelibrary.wiley.com/doi/full/10.1002/ece3.71067.