Phylogeography of Southern Water Vole (Arvicola sapidus): evidence for refugia within the Iberian glacial refugium?

Abstract

The role of Southern European peninsulas as glacial refugia for temperate species has been widely established, but phylogeographic patterns within refugia are being only recently addressed. Here we describe the phylogeographic patterns for Southern water vole (Arvicola sapidus) in its whole distribution across Iberia and France. Control region and cytochrome b sequences were obtained for 228 samples from 130 localities across Iberia and France. Eighty-five haplotypes were found in total yielding a high overall mitochondrial diversity (pi = 0.027; H = 0.974). Phylogeographic structure was relatively shallow (3.1% average intraspecific divergence) with few supported clades and 95% and 90% maximum parsimony unconnected networks, but significant, as reflected in increased pairwise nucleotide divergences with distance (r = 0.197, P = 0.03) and significant autocorrelation up to approximately 500 km. Spatial analysis of molecular variance analysis detected seven geographical groups explaining 43.73% of the total mitochondrial variation. We detected demographic expansions in three of these groups. A recent colonization of France from Iberia was suggested and estimated around 62 000 years bp by an isolation-with-migration model. Our results suggest the contribution of episodes of isolation in glacial subrefugia in Iberia, but seem to exclude a long-term isolation over successive glacial cycles. Phylogeographic divergence was probably tempered by relatively large population sizes and rapid and extensive mixing among subrefugia during interglacials, that might have eroded the phylogeographic structure accumulated at glacial peaks. Phenotypic differences in A. sapidus do not delineate historically isolated intraspecific divisions and do not warrant subspecific delimitations. Our results do support the existence of subrefugia within Iberia and their role in promoting intraspecific divergences.

Salamandra salamandra (Amphibia: Caudata: Salamandridae) in Portugal: not all black and yellow

“…An exhaustive list can be found in Gómez and Lunt (2007, and references therein). Recently, further evidence supporting this theory included the rotifer Brachionus plicatilis (Campillo et al 2011), the grasshopper Chorthippus parallelus (Bella et al 2007), the Mediterranean toad (Alytes cisternasii) (Gonçalves et al 2009), the red-legged partridge (Alectoris rufa) (Ferrero et al 2011), the field vole, Microtus agrestis (Jaarola and Searle 2003), and the southern water vole (Arvicola sapidus) (Centeno-Cuadros et al 2009). …”

Phylogeography and postglacial expansion of the endangered semi-aquatic mammal Galemys pyrenaicus

“…Our results further extend this hypothesis by showing that peninsulas would have helped to develop, not only complex isolation mechanisms, but also the whole glacial processes of contraction and dispersal, leaving strong footprints on the genetic structure of endemic species such as the Pyrenean desman. Although these clear genetic traces had been mostly identified in species of continental distribution [7], some of which left distinctive lineages [79] or even species [80,81] in the southern peninsulas, a growing number of endemic or semi-endemic species shows similarly complex population history patterns within the Iberian Peninsula [72,82-85]. We show here that the genetic structure of the Pyrenean desman, a highly specialized mammal, was also affected by the whole glacial processes at a peninsular scale.…”

Phylogeography of the Eurasian green woodpecker (Picus viridis)

“…As the genetic diversity is much higher in central Spain than in Catalonia and southern France, we suggest, in line with the leading‐edge expansion hypothesis (Hewitt, 2000), a northward colonization of the whole Iberian Peninsula by the sharpei lineage from permanent refugia located somewhere in southern or central Spain. The existence of restricted southern refugia within the Iberian Peninsula has recently been proposed for terrestrial mammals and other organisms (Weiss & Ferrand, 2007; Centeno‐Cuadros et al. , 2009) but remains to be evaluated with regard to birds.…”