Oscillations, Geographical distribution, Arctic Regions, Migration, Marine animals, Basins, Mitochondrial DNA, Divergence, Isolation, Pleistocene, Deoxyribonucleic acid, DNA, Quaternary, Fauna, speciation, Nucleotide sequence, Ocean basins, Geographic distribution, Polar environments, Marine fauna, isolation with migration, elasmobranch, Greenland shark, Som...