title: The importance of time scale and multiple refugia: incipient speciation and admixture of lineages in the butterfly Erebia triaria (Nymphalidae).
abstract: Evidence of four different Quaternary glacial stages has been found in NW Iberia. The different magnitude of these episodes probably conditioned the distribution of currently montane species. We examined if the population history of NW Iberian Erebia triaria butterflies reflected such an influence of different glacial stages. We also investigated whether these populations were post-glacially colonised from a single refugial area or several sources. For this, we performed phylogenetic analyses and coalescence simulations on mitochondrial DNA sequences of individuals from five NW Iberian locations. We analysed three additional populations as reference, i.e., Central Spain, the Pyrenees, and the Alps. One of the NW Iberian populations, a subspecies endemic to a particular mountain range (Xistral), showed a high level of genetic divergence from all other populations, regardless of their geographic distance. Isolation after an ancient glacial stage, and followed by allopatric differentiation, may account for such high differentiation. The genetic pattern shown by the rest of the NW Iberian population samples consisted of two lineages, likely reflecting that the ancestors of these populations sought for refuge in at least two different areas during a subsequent glacial stage. We showed evidence of both temporal and spatial divisions in the phylogeography of these butterflies. The congruence of this pattern with the geological history suggests that the Iberian Peninsula hosted several refugial areas that differed in area and location depending on the glacial stage.
authors.affiliation: Department of Ecology and Evolution (Animal Ecology), Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden.
authors.forename: Marta
authors.initials: M
authors.lastname: Vila
authors.forename: Juan R
authors.initials: JR
authors.lastname: Vidal-Romaní
authors.forename: Mats
authors.initials: M
authors.lastname: Björklund
mesh_terms: D000818:Animals; D002080:Butterflies / Q000145:classification / Q000235:genetics*; D004272:DNA, Mitochondrial / Q000737:chemistry / Q000235:genetics; D003576:Electron Transport Complex IV / Q000235:genetics; D014644:Genetic Variation; D005843:Geography; D006239:Haplotypes; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D013030:Spain; D013045:Species Specificity; D013997:Time Factors
chemical_list: D004272:DNA, Mitochondrial; D003576:Electron Transport Complex IV