Increased genetic structuring of isolatedSalamandra salamandrapopulations (Caudata: Salamandridae) at the margins of the Carpathian Mountains

Abstract

The traditional southern Pleistocene refugia hypothesis in Europe has lately been challenged for several animal and plant species. The Carpathian Basin, especially at the marginal regions, is one of the recently recognized biodiversity hotspots in Europe. Marginal populations are prone to have lower genetic diversity and higher genetic differentiation than central populations. Here, we examined one mitochondrial DNA fragment (D‐loop) and nine nuclear (microsatellite) loci to describe the genetic diversity and phylogeographical pattern of fire salamander (Salamandra salamandra) populations in the Carpathian Basin with focusing on the southern margins of the Western Carpathians, where isolated populations of this species are present. Analyses of microsatellites indicated reduced genetic diversity for most of the isolated populations. Based on the mitochondrial DNA, only two haplotypes were found, whereas the analyses with the nuclear markers revealed a more recent genetic split between Western (Alpine) and Eastern (Carpathian) populations, and separated the Apuseni Mountains population (part of the Western Carpathians). Using approximate Bayesian computation analyses, we identified the most probable colonization scenario for the isolated North Hungarian Carpathian Basin populations. The split between isolated salamander populations from the central populations in the Carpathian Mountains dates back to the beginning of the Late Pleistocene, while the split between most of the Hungarian populations can be associated with the Last Glacial Maximum. We found evidence for long‐time isolation between the marginal Carpathian Basin and central populations. Our results also show that S. salamandra survived glacial periods in the temperate forests of north‐east Pannonia (North Hungarian Mountains), confirming that the Carpathian Basin served as important northerly refugia during the Pleistocene climatic oscillations.

Mitochondrial DNA diversity of the alpine newt (Ichthyosaura alpestris) in the Carpathian Basin: evidence for multiple cryptic lineages associated with Pleistocene refugia

“…This diversity mirrors patterns of genetic structure in numerous co-distributed taxa. For instance, an east-west genetic split has been documented in the Alpine and Carpathian lineages of Bombina variegata and Salamandra salamandra (Vörös et al 2006, Vörös et al 2016b, in Anguis fragilis and A. colchica inhabiting Transdanubia and the North Hungarian Mountains (Szabó & Vörös 2014), and in the Carpathian and Balkan clades of the adder, Vipera berus (Ursenbacher et al 2006). Similar patterns of genetic differentiation have also been reported in some butterfly species in the Carpathian Basin.…”

“…This old divergence is associated with the high species and endemic richness of the region, making Apuseni Mts one of the major biodiversity hotspots in the Carpathians. The distinctiveness of the Apuseni Mts Ichthyosaura alpestris population underpins the importance of these mountains as a biogeographically distinct region with a high number of endemic taxa, including earthworms (Pop et al 2010), aquatic insects (Bálint et al 2011), and a distinct Salamandra salamandra lineage (Vörös et al 2016b).…”

Landscape resistance constrains hybridization across contact zones in a reproductively and morphologically polymorphic salamander

“…In addition, the climatic heterogeneity associated with the mountain ridges (e.g. higher wind exposure, colder climate, shorting of the growing season, or rarefaction of surface water bodies) often act as impermeable barriers to fire salamanders 38 , 85 , other salamander species 86 – 89 , and anurans 90 . On the other hand, the relatively smooth topography across NG and consequent softer climate transitions in the west–east corridors (i.e.…”

Genetic structure of lake and stream populations in a Pyrenean amphibian ( Calotriton asper ) reveals evolutionary significant units associated with paedomorphosis

“…A total of 10 independent runs were made with one million Markov chain Monte Carlo (MCMC) iterations, discarding the first 100,000 MCMC steps as a burn‐in phase. To avoid a bias as a result of the sensitivity of STRUCTURE due to the sample size of each distinct population, the same simulation has been run with a maximum of 20 samples per population (Vörös et al., ). STRUCTURE HARVESTER version 0.6.94 was used to determine the Δ K using the Evanno method (Earl & vonHoldt, ).…”