Searching for the glacial refugia ofErebia euryale(Lepidoptera, Nymphalidae) - insights from mtDNA- and nDNA-based phylogeography in the Western Carpathians

Linking large-scale genetic structure of three Argynnini butterfly species to geography and environment

Understanding which factors and processes are associated with genetic differentiation within and among species remains a major goal in evolutionary biology. To explore differences and similarities in genetic structure and its association with geographical and climatic factors in sympatric sister species, we conducted a large‐scale (>32° latitude and >36° longitude) comparative phylogeographical study on three Argynnini butterfly species (Speyeria aglaja, Fabriciana adippe and F. niobe) that have similar life histories, but differ in ecological generalism and dispersal abilities. Analyses of nuclear (ddRAD‐sequencing derived SNP markers) and mitochondrial (COI sequences) data revealed differences between species in genetic structure and how genetic differentiation was associated with climatic factors (temperature, solar radiation, precipitation, wind speed). Geographical proximity accounted for much of the variation in nuclear and mitochondrial structure and evolutionary relationships in F. adippe and F. niobe, but only explained the pattern observed in the nuclear data in S. aglaja, for which mitonuclear discordance was documented. In all species, Iberian and Balkan individuals formed genetic clusters, suggesting isolation in glacial refugia and limited postglacial expansion. Solar radiation and precipitation were associated with the genetic structure on a regional scale in all species, but the specific combinations of environmental and geographical factors linked to variation within species were unique, pointing to species‐specific responses to common environments. Our findings show that the species share similar colonization histories, and that the same ecological factors, such as niche breadth and dispersal capacity, covary with genetic differentiation within these species to some extent, thereby highlighting the importance of comparative phylogeographical studies in sympatric sister species.

Phylogeography and potential glacial refugia of terrestrial gastropod Faustina faustina (Rossmässler, 1835) (Gastropoda: Eupulmonata: Helicidae) inferred from molecular data and species distribution models

Faustina faustina is a conchologically highly diverse forest gastropod with several morphological forms. It is a Carpathian species, but it also occurs in northern isolated localities, where it was probably introduced. We performed the first phylogeographic analysis of 22 populations, based on three molecular markers: COI, ITS-2, and 28S rRNA. Genetic data were complemented by paleo-distribution models of spatial occupancy during the Last Glacial Maximum to strengthen inferences of refugial areas. We discovered high genetic variability of COI sequences with p-distances between haplotypes ranged from 0.2 to 18.1% (6.3–16.6% between clades). For nuclear markers, a haplotype distribution pattern was revealed. Species distribution models indicated a few potential refugia in the Carpathians, with the most climatically stable and largest areas in the Southern Carpathians. In some climate scenarios, putative microrefugia were also predicted in the Western and Eastern Carpathians, and in the Apuseni Mts. Our results suggest the glacial in situ survival of F. faustina and its Holocene expansion in the Sudetes. Although our genetic data as well as shell phenotypes showed considerable variation within and between studied populations, the molecular species delimitation approaches still imply only one single species. Our study contributes to the understanding of the impact of processes on shaping contemporary population genetic structure and diversity in low-dispersal, forest species.