Serial population extinctions in a small mammal indicate Late Pleistocene ecosystem instability

• Published in: Proceedings of the National Academy of Sciences
• Main Authors: Brace, Selina, Palkopoulou, Eleftheria, Dalén, Love, Lister, Adrian M., Miller, Rebecca, Otte, Marcel, Germonpré, Mietje, Blockley, Simon P. E., Stewart, John R., Barnes, Ian
• Format: Text
• Language: English
• Published: National Academy of Sciences 2012
• Subjects: Biological Sciences; Dicrostonyx torquatus; Tundra
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3528586; http://www.ncbi.nlm.nih.gov/pubmed/23185018; https://doi.org/10.1073/pnas.1213322109

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.