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 climateassociated, 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. megafauna | palaeogenetics | palaeoclimate | modelling

The colonization history of British water vole (Arvicola amphibius(Linnaeus, 1758)): origins and development of the Celtic fringe

“…Six primer pairs were designed specifically for this study (electronic supplementary material, table S2), each pair amplifying short (150-200 base pair) overlapping fragments. PCR reactions, amplicon purification and sequencing were performed as described in [2] with PCR primer-specific annealing temperatures ranging from 508C to 528C. Standard ancient DNA protocols [23] were followed throughout these extraction procedures to prevent contamination, with repeated PCR amplification and sequencing of fragments to ensure DNA authenticity and the absence of miscoding lesions.…”

“…The Lateglacial was a period of rapid vegetational change and widespread faunal extinction and translocation across Eurasia [2,3]. It may be viewed as the most recent example of the dramatic climatic fluctuations associated with the Pleistocene, where over the last 2.6 million years (Myr) ice sheets periodically spread down from the north, leaving Northern Europe almost fully glaciated and permafrost extending throughout Central Europe with only the southernmost peninsulae remaining ice and permafrost free [4].…”

“…[2,12,13]). Here, we focus on one of the 'Celtic fringe' species, the northern water vole, Arvicola amphibius (also referred to as A. terrestris), a widely distributed species found across Europe (excluding Ireland and central and southern Spain), east through Siberia to the Lena River Basin, and from the Arctic Sea south to Lake Baikal and Northwest China through north west Iran, Iraq, north Israel, the Caucasus and Turkey [14].…”

“…It may be viewed as the most recent example of the dramatic climatic fluctuations associated with the Pleistocene, where over the last 2.6 million years (Myr) ice sheets periodically spread down from the north, leaving Northern Europe almost fully glaciated and permafrost extending throughout Central Europe with only the southernmost peninsulae remaining ice and permafrost free [4]. During the last full glacial cycle, the maximum extent of glaciation (the last glacial maximum or LGM; ca 22 500 BP) extended across Scandinavia and the British Isles, with large parts of Europe becoming too cold for many mammal species to survive ( [2,5], but see [6]). Hewitt [7 -9] made significant progress in the development of a model of organismal response to Holarctic climate change, proposing that in Europe temperate populations survived periods of climatic deterioration in three refugial peninsulae (Iberia, Italy and the Balkans), before recolonizing northwards as glaciers retreated.…”

Analysis of collagen preservation in bones recovered in archaeological contexts using NIR Hyperspectral Imaging

“…NIRS-HCI analyses of the fauna will contribute to these questions by clarifying differences in faunal taphonomy within and between strata, leading to further analyses that will refine our understanding of palaeoenvironmental and climatic change observed within a single sediment sequence. At Trou Al'Wesse, ongoing ancient DNA analyses of fauna (see e.g., [31][32]) may benefit in the near future from appraisal of potential samples by NIRS-HCI analyses.…”