Genomic insights on the extinct Baltic harp seal population

• The harp seal is a cold adapted seal species, which requires a suitable formation of pack ice during winter and spring to secure successfully breeding. Today harp seals live in sub-Arctic regions and the North Atlantic, but during the middle Holocene Period, a breeding population existed in the Baltic Sea. In order to investigate the genetic affinity and faith of the now extinct Baltic harp seal population we analysed contemporary and ancient mitogenomes from across the species contemporary and ancient range. Ancient mitochondrial genomes were generated for a total of 49 Baltic harp seals ranging from Late Mesolithic to the Iron Age, together with five Neolithic samples from the White Sea and two Neolithic samples from the Northwest Atlantic Ocean. The ancient data was compared to published modern harp seal data assigned to the present breeding populations around Newfoundland, the Greenland Sea and the White Sea. Surprisingly only limited phylogenetic resolution was found among the ancient and modern localities. The statistical measures for genetic differentiation, however, identified significant levels of population genetic differentiation between the Baltic harp seal population and all modern populations, which suggest an independent breeding population in the Baltic Sea. The low level of genetic differentiation to the White Sea population indicate a shared ancestry between the Baltic and White Sea. The generated Skyline plot suggest second wave of colonization after a hiatus in the Baltic Sea. Interestingly, the genetic diversity in the Baltic harp seal population was significantly higher than in any of the modern populations. However, a drastic decrease in genetic diversity is observed from the Bronze Age to the Iron Age, which might be linked to effects of high hunting pressure and climatic changes towards the final extirpation of harp seals in the Baltic. 

Ämnesord

HUMANIORA  -- Historia och arkeologi -- Arkeologi (hsv//swe)

HUMANITIES  -- History and Archaeology -- Archaeology (hsv//eng)

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Geologi (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Geology (hsv//eng)

Nyckelord

Ancient DNA

Baltic Sea

breeding population

haplotype

hunting

migration

Archaeological Science

laborativ arkeologi

Geology

geologi

Publikations- och innehållstyp

vet (ämneskategori)

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