biostudies-literatureHold KScience for Life LaboratoryNorges ForskningsrådNTNU Norwegian University of Science and TechnologySvenska Forskningsrådet FormasSvalbard Environmental Protection FundSvalbard Environmental Protection Fund4143https://www.ebi.ac.uk/biostudies/studies/S-EPMC10876933biostudies-literatureUnknown14(1)Climate warming at the end of the last glacial period had profound effects on the distribution of cold-adapted species. As their range shifted towards northern latitudes, they were able to colonise previously glaciated areas, including remote Arctic islands. However, there is still uncertainty about the routes and timing of colonisation. At the end of the last ice age, reindeer/caribou (Rangifer tarandus) expanded to the Holarctic region and colonised the archipelagos of Svalbard and Franz Josef Land. Earlier studies have proposed two possible colonisation routes, either from the Eurasian mainland or from Canada via Greenland. Here, we used 174 ancient, historical and modern mitogenomes to reconstruct the phylogeny of reindeer across its whole range and to infer the colonisation route of tScientific reportsAncient reindeer mitogenomes reveal island-hopping colonisation of the Arctic archipelagos.PMC10876933325589NP0003915/1052760802019-0027514/137Hold KEllegaard MRHansen BBRasmussen JAMartin MDRoed KHBrealey JCDalen LYannic GLe Moullec MGuschanski KDussex NKellner FLLord EBieker VCfalseAncient reindeer mitogenomes reveal island-hopping colonisation of the Arctic archipelagos.Climate warming at the end of the last glacial period had profound effects on the distribution of cold-adapted species. As their range shifted towards northern latitudes, they were able to colonise previously glaciated areas, including remote Arctic islands. However, there is still uncertainty about the routes and timing of colonisation. At the end of the last ice age, reindeer/caribou (Rangifer tarandus) expanded to the Holarctic region and colonised the archipelagos of Svalbard and Franz Josef Land. Earlier studies have proposed two possible colonisation routes, either from the Eurasian mainland or from Canada via Greenland. Here, we used 174 ancient, historical and modern mitogenomes to reconstruct the phylogeny of reindeer across its whole range and to infer the colonisation route of t2024-01-01T00:00:00Z2024 Feb2026-05-29T11:40:30.984Z2025-04-19T07:33:54.92ZS-EPMC108769333837442110.1038/s41598-024-54296-2