![]() Zooarchaeologists have relied upon various approaches to study the impacts of harvest pressure and environmental change on ungulate populations, such as analysis of prey mortality patterns and morphometrics. This study shows ancient mitochondrial capture between two Arctic species and emphasizes the importance of multilocus approaches for phylogenetic inference. groenlandicus, with advanced dental morphology originated from a later colonization event across the Bering Land Bridge. Species widely distributed in the North American Arctic, D. hudsonius with primitive and distinct molar morphology represents a relic of the first migration event from Eurasia to North America. The nuclear genome phylogeny reveals species cladogenesis and supports the hypothesis that D. The mitogenome tree likely reflects ancient mitochondrial replacement between currently isolated D. The nuclear and mitogenome phylogenies support reciprocal monophyly of each species but reveal conflicting relationships among species. hudsonius and evaluate biogeographic hypothesis of the two colonization events of North America from Eurasia based on morphological variation in dental traits. We examined mitochondrial and nuclear genomic variation to reconstruct phylogenetic relationships among the Eurasian D. richardsoni.Ĭollared lemmings (Dicrostonyx) are cold adapted rodents, keystone animals in the tundra communities and the model taxa in studies of Arctic genetic diversity and Quaternary paleontology. Our study calls for further taxonomical investigations for collared lemmings from the overlapping distribution ranges of D. They also suggest that these lemmings should have a peculiar taxonomic status. These differences suggest that collared lemmings from the Baker Lake-Aberdeen Lake area may not be correctly assigned to either of the two species without further genetic evaluation. ![]() However, skull shapes proved inefficient in discriminating between species. ![]() groenlandicus, and the lemmings from the Baker Lake-Aberdeen Lake area showed significant differences, especially when considering skull shapes, thus suggesting three distinct groups. hudsonius, and the remainder of lemmings. Multivariate analyses revealed two distinct groups when considering the molars: D. We compared 2D outline shapes of the skull and three upper molars of collared lemmings collected from seven areas of the Canadian Arctic, including specimens from the Baker Lake-Aberdeen Lake area, in the Kivalliq Region, and D. Possible sympatry of both species obscures the taxonomic status of collared lemmings from this area. ![]() This issue is particularly important in the Kivalliq Region, Nunavut, Canada, where D. Morphological differentiation and relationships among collared lemmings (Dicrostonyx) remain unclear. richardsoni, it seems most probable that the species survived the LGM in a southern refugium. While more data are required to determine whether or not the LGM southern population is ancestral to extant D. richardsoni habitat, rather than the very cold, dry tundra of the Northern Arctic. This suggests a palaeoclimate south of the Laurentide ice sheet that contains elements similar to the more temperate shrub tundra characteristic of extant D. Our results indicate that LGM-age Dicrostonyx from Iowa and South Dakota belong to Dicrostonyx richardsoni, which currently lives in a temperate tundra environment west of Hudson Bay, Canada. We test whether the Dicrostonyx populations from LGM-age continental USA became extinct at the Pleistocene-Holocene transition ~11000 years ago or, alternatively, if they belong to an extant species whose habitat preferences can be used to infer the palaeoclimate along the glacial margin. To better understand these communities and the fate of these southern individuals, we compare mitochondrial cytochrome b sequence data from three LGM-age Dicrostonyx fossils from south of the Laurentide ice sheet to sequences from modern Dicrostonyx sampled from across their present-day range. However, during the last glacial maximum (LGM), Dicrostonyx lived along the southern ice margin of the Laurentide ice sheet in communities comprising both temperate and boreal species. Collared lemmings (genus Dicrostonyx) are circumpolar Arctic arvicoline rodents associated with tundra. ![]()
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