title: On the origin of the Norwegian lemming.
abstract: The Pleistocene glacial cycles resulted in significant changes in species distributions, and it has been discussed whether this caused increased rates of population divergence and speciation. One species that is likely to have evolved during the Pleistocene is the Norwegian lemming (Lemmus lemmus). However, the origin of this species, both in terms of when and from what ancestral taxon it evolved, has been difficult to ascertain. Here, we use ancient DNA recovered from lemming remains from a series of Late Pleistocene and Holocene sites to explore the species' evolutionary history. The results revealed considerable genetic differentiation between glacial and contemporary samples. Moreover, the analyses provided strong support for a divergence time prior to the Last Glacial Maximum (LGM), therefore likely ruling out a postglacial colonization of Scandinavia. Consequently, it appears that the Norwegian lemming evolved from a small population that survived the LGM in an ice-free Scandinavian refugium.
authors.affiliation: Department of Bioinformatics and Genetics, Swedish Museum of Natural History, 10405, Stockholm, Sweden; Department of Zoology, Stockholm University, 10405, Stockholm, Sweden.
authors.forename: Vendela K
authors.initials: VK
authors.lastname: Lagerholm
authors.forename: Edson
authors.initials: E
authors.lastname: Sandoval-Castellanos
authors.forename: Dorothee
authors.initials: D
authors.lastname: Ehrich
authors.forename: Natalia I
authors.initials: NI
authors.lastname: Abramson
authors.forename: Adam
authors.initials: A
authors.lastname: Nadachowski
authors.forename: Daniela C
authors.initials: DC
authors.lastname: Kalthoff
authors.forename: Mietje
authors.initials: M
authors.lastname: Germonpré
authors.forename: Anders
authors.initials: A
authors.lastname: Angerbjörn
authors.forename: John R
authors.initials: JR
authors.lastname: Stewart
authors.forename: Love
authors.initials: L
authors.lastname: Dalén
mesh_terms: D000818:Animals; D003411:Arvicolinae / Q000235:genetics*; D001499:Bayes Theorem; D005075:Biological Evolution; D004272:DNA, Mitochondrial / Q000235:genetics; D005580:Fossils; D014644:Genetic Variation; D005828:Genetics, Population; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009664:Norway; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial
keywords: Lemmus; Pleistocene; ancient DNA; colonization; extinction; speciation