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

The narrow-headed vole, collared lemming and common vole were the most abundant small mammal species across the Eurasian Late Pleistocene steppe-tundra environment. Previous ancient DNA studies of the collared lemming and common vole have revealed dynamic population histories shaped by climatic fluctuations. To investigate the extent to which species with similar adaptations share common evolutionary histories, we generated a dataset comprised the mitochondrial genomes of 139 ancient and 6 modern narrow-headed voles from several sites across Europe and northwestern Asia covering approximately the last 100 thousand years (kyr). We inferred Bayesian time-aware phylogenies using 11 radiocarbon-dated samples to calibrate the molecular clock. Divergence of the main mtDNA lineages across the three species occurred during marine isotope stages (MIS) 7 and MIS 5, suggesting a common response of species adapted to open habitat during interglacials. We identified several time-structured mtDNA lineages in European narrow-headed vole, suggesting lineage turnover. The timing of some of these turnovers was synchronous across the three species, allowing us to identify the main drivers of the Late Pleistocene dynamics of steppe- and cold-adapted species.

A late Neandertal femur from Les Rochers-de-Villeneuve, France.

In 2002, a Neandertal partial femoral diaphysis was discovered at Les Rochers-de-Villeneuve (Vienne, France). Radiocarbon dated to approximately 40,700 14C years before present, this specimen is one of the most recent Middle Paleolithic Neandertals. The diaphysis derives from an archeological level indicating alternating human and carnivore (mostly hyena) occupation of the cave, reinforcing the close proximity and probable competition of Middle Paleolithic humans with large carnivores for resources and space. Morphological aspects of the diaphysis and ancient DNA extracted from it indicate that it is aligned with the Neandertals and is distinct from early modern humans. However, its midshaft cortical bone distribution places it between other Middle Paleolithic Neandertals and the Châtelperronian Neandertal from La Roche-à-Pierrot, supporting a pattern of changing mobility patterns among late Middle Paleolithic Neandertals on the eve of modern human dispersals into Europe.