title: Serial population extinctions in a small mammal indicate Late Pleistocene ecosystem instability.
abstract: The Late Pleistocene global extinction of many terrestrial mammal species has been a subject of intensive scientific study for over a century, yet the relative contributions of environmental changes and the global expansion of humans remain unresolved. A defining component of these extinctions is a bias toward large species, with the majority of small-mammal taxa apparently surviving into the present. Here, we investigate the population-level history of a key tundra-specialist small mammal, the collared lemming (Dicrostonyx torquatus), to explore whether events during the Late Pleistocene had a discernible effect beyond the large mammal fauna. Using ancient DNA techniques to sample across three sites in North-West Europe, we observe a dramatic reduction in genetic diversity in this species over the last 50,000 y. We further identify a series of extinction-recolonization events, indicating a previously unrecognized instability in Late Pleistocene small-mammal populations, which we link with climatic fluctuations. Our results reveal climate-associated, repeated regional extinctions in a keystone prey species across the Late Pleistocene, a pattern likely to have had an impact on the wider steppe-tundra community, and one that is concordant with environmental change as a major force in structuring Late Pleistocene biodiversity.
authors.affiliation: School of Biological Sciences and Department of Geography,  Royal Holloway University of London, Egham, Surrey TW20 0EX,  United Kingdom.
authors.forename: Selina
authors.initials: S
authors.lastname: Brace
authors.forename: Eleftheria
authors.initials: E
authors.lastname: Palkopoulou
authors.forename: Love
authors.initials: L
authors.lastname: Dalén
authors.forename: Adrian M
authors.initials: AM
authors.lastname: Lister
authors.forename: Rebecca
authors.initials: R
authors.lastname: Miller
authors.forename: Marcel
authors.initials: M
authors.lastname: Otte
authors.forename: Mietje
authors.initials: M
authors.lastname: Germonpré
authors.forename: Simon P E
authors.initials: SP
authors.lastname: Blockley
authors.forename: John R
authors.initials: JR
authors.lastname: Stewart
authors.forename: Ian
authors.initials: I
authors.lastname: Barnes
mesh_terms: D000818:Animals; D003411:Arvicolinae / Q000145:classification / Q000235:genetics; D044822:Biodiversity; D057231:Climate Change; D004272:DNA, Mitochondrial / Q000235:genetics; D017753:Ecosystem; D005060:Europe; D019143:Evolution, Molecular; D053476:Extinction, Biological; D005580:Fossils; D008969:Molecular Sequence Data; D010163:Paleontology; D010802:Phylogeny; D011157:Population Dynamics
chemical_list: D004272:DNA, Mitochondrial