A complex scenario of glacial survival in Mediterranean and continental refugia of a temperate continental vole species ( Microtus arvalis ) in Europe
Résumé
The role of glacial refugia in shaping contemporary species distribution is a longstanding
question in phylogeography and evolutionary ecology. Recent studies are
questioning previous paradigms on glacial refugia and postglacial recolonization
pathways in Europe, and more flexible phylogeographic scenarios have been proposed.
We used the widespread common vole Microtus arvalis as a model to investigate
the origin, locations of glacial refugia, and dispersal pathways, in the group of
“Continental” species in Europe. We used a Bayesian spatiotemporal diffusion analysis
(relaxed random walk model) of cytochrome b sequences across the species range,
including newly collected individuals from 10 Iberian localities and published sequences
from 68 localities across 22 European countries. Our data suggest that the
species originated in Central Europe, and we revealed the location of multiple refugia
(in both southern peninsulas and continental regions) for this continental model species.
Our results confirm the monophyly of Iberian voles and the pre‐LGM divergence
between Iberian and European voles. We found evidence of restricted postglacial dispersal
from refugia in Mediterranean peninsulas. We inferred a complex evolutionary and demographic history of M. arvalis in Europe over the last 50,000 years that does
not adequately fit previous glacial refugial scenarios. The phylogeography of M. arvalis
provides a paradigm of ice‐age survival of a temperate continental species in
western and eastern Mediterranean peninsulas (sources of endemism) and multiple
continental regions (sources of postglacial spread). Our findings also provide support
for a major role of large European river systems in shaping geographic boundaries of
M. arvalis in Europe.