Ancient DNA reveals interstadials as a driver of common vole population dynamics during the last glacial period

Abstract

AimThe common vole is a temperate rodent widespread across Europe. It was also one of the most abundant small mammal species throughout the Late Pleistocene. Phylogeographic studies of its extant populations suggested the Last Glacial Maximum (LGM, 26.5-19 ka ago) as one of the main drivers of the species' population dynamics. However, analyses based solely on extant genetic diversity may not recover the full complexity of past population history. The main aim of this study was to investigate the evolutionary history and identify the main drivers of the common vole population dynamics during the Late Pleistocene. Location Europe Taxon Common vole (Microtus arvalis) MethodsWe generated a dataset comprising 4.2 kb-long fragment of mitochondrial DNA from 148 ancient and 51 modern specimens sampled from multiple localities across Europe and covering the last 60 thousand years (ka). We used Bayesian inference to reconstruct their phylogenetic relationships and to estimate the age of specimens that were not directly dated. ResultsWe estimate the time to the most recent common ancestor of all Last Glacial and extant common vole lineages to 90 ka ago and the divergence of the main mtDNA lineages present in extant populations to between 55 and 40 ka ago, earlier than previous estimates. We find multiple lineage turnovers in Europe in the period of high climate variability at the end of Marine Isotope Stage 3 (MIS 3; 57-29 ka ago) in addition to those found previously around the Pleistocene/Holocene transition. Conversely, data from the Western Carpathians suggest continuity throughout the LGM even at high latitudes. Main conclusions.

Ancient DNA of narrow-headed vole reveal common features of the Late Pleistocene population dynamics in cold-adapted small mammals

“…The estimated age of diversification of the main mtDNA lineages found in the European and Asiatic narrow-headed voles from the last glacial period was similar to the estimated diversification of the main lineages within common voles [ 12 ] and Eurasian collared lemmings [ 11 ] that occurred during MIS 5c (Brørup interstadial; ∼GI 23) ( figure 2 ).…”

“…Colours indicate mtDNA lineages presented in figure 3 . Data for collared lemming are from [ 11 ] and for common vole from [ 12 ]. …”

“…The phylogenetic relationships between the presented mtDNA lineages are shown in figure 2 b . Data for the collared lemming are from [ 8 , 9 ] and for the common vole from [ 12 ]. The oxygen isotope record ( δ 18 O V-SMOW) from the Greenland Ice cores (GICC05) [ 62 ] is given on the right side.…”

“…However, less is known about the Late Pleistocene evolutionary histories of small mammals. The notable exceptions are the ancient DNA investigations of the collared lemming (Dicrostonyx torquatus) [8][9][10][11] and the common vole (Microtus arvalis) [12,13]. These studies revealed that both species experienced several mtDNA lineage replacements across most of the European continent during marine isotope stage (MIS) 3 and MIS 2 [8,9,13].…”

Ancient DNA Contradicts the Presence of Social Voles (Genus Microtus, Subgenus Sumeriomys) in the Late Pleistocene of Western Europe

“…MapDamage v.2.08 [28] was used to assess the damage patterns and length distribution of the DNA molecules. In the case of specimens identified as S. anglicus we called the entire mtDNA genome, while in the case of M. arvalis we called only 4.2 kb fragment as in Baca et al [29] (see Supplementary Information for more details).…”