Diversity among peripheral populations: genetic and evolutionary differentiation ofSalamandra atraat the southern edge of the Alps

Abstract

Separate populations at the edge of a species range are receiving great attention and have been shown to be often different from populations in the core area. However, it has rarely been tested whether neighboring peripheral populations are genetically and evolutionarily similar to each other, as expected for their geographical proximity and similar ecological conditions, or differ due to historical contingency. We investigated isolation and differentiation, within‐population genetic diversity and evolutionary relationships among multiple peripheral populations of a cold‐adapted terrestrial salamander, Salamandra atra, at the southern edge of the species core range. We carried out population genetic, phylogeographic, and phylogenetic analyses on various molecular markers (10 autosomal microsatellite loci, three mitochondrial loci with total length >2,100 bp, two protein‐coding nuclear genes) sampled from more than 100 individuals from 13 sites along the southern Prealps. We found at least seven isolated peripheral populations, all highly differentiated from the remaining populations and differentiated from each other at various levels. The within‐population genetic diversity was variable in the peripheral populations, but consistently lower than in the remaining populations. All peripheral populations along the southern Prealps belong to an ancient lineage that is also found in the Dinarides but did not contribute to the postglacial recolonization of the inner and northern Alps. All fully melanistic populations from the Orobian mountains to the southern Dinarides represent a single clade, to the exclusion of the two yellow‐patched populations inhabiting the Pasubio massif and the Sette Comuni plateau, which are distinguished as S. atra pasubiensis and S. atra aurorae, respectively. In conclusion, multiple populations of S. atra at the southern edge of the species core area have different levels of differentiation, different amount of within‐population genetic diversity, and different evolutionary origin. Therefore, they should be regarded as complementary conservation targets to preserve the overall genetic and evolutionary diversity of the species.

Recent genetic connectivity and clinal variation in chimpanzees

“…We scored individual genotypes (allele length polymorphism) at up to 14 microsatellite markers, as these are cost effective and allow for accurate genotyping of non-invasively collected samples 39 . Previous studies in other species (fruit flies 40 , fish 41,42 , birds 43 , amphibians 44 , wild boars 34 , felids 45 and beetles 46 ) have demonstrated that 6-14 microsatellite loci are informative enough to even detect subtle population structure. Furthermore, a previous study of how sampling affects detection of chimpanzee population structure found that eleven loci were sufficient to overcome false signals of population structure caused by sampling bias and uncover a signal of IBD 9 .…”

Toxin variation among salamander populations: discussing potential causes and future directions

“…2011), but several more isolated populations exist within the Dinaric Alps which belong to a separate subspecies Salamandra atra prenjensis Mikšić, 1969 (Bonato et al . 2018; Šunje et al . 2019).…”

“…Our study focuses on the Alpine salamander (Salamandra atra Laurenti, 1768). This species has a wide, continuous distribution within the European Alps (Arnold & Ovenden 2002; Jeran et al 2011), but several more isolated populations exist within the Dinaric Alps which belong to a separate subspecies Salamandra atra prenjensis Mikšić, 1969(Bonato et al 2018Šunje et al 2019). Salamandra atra is a strictly terrestrial species that spends a large portion of its life hidden in crevices, under stones or logs, in burrows of mammals, etc.…”

Diversity and structure of fragmented populations of a threatened endemic cyprinodontid (Aphanius sophiae) inferred from genetics and otolith morphology: Implications for conservation and management

“…Anthropogenic disturbances, such as dams, flow regulation, and pollution, increase habitat fragmentation and isolation, thus reducing genetic exchange and genetic diversity (Alcaraz, Carmona‐Catot, et al, ; Díez‐del‐Molino et al, ; Faulks et al, ). Consequently, understanding genetic diversity, population structure within and among populations, spatial distribution patterns, and the presence of dispersal barriers are critical to quantify the degree of genetic exchange and to identify isolated populations (Bonato et al, ; Casal‐López et al, ; Chung et al, ). This information is essential in designing effective habitat management and species conservation plans.…”

“…Consequently, understanding genetic diversity, population structure within and among populations, spatial distribution patterns, and the presence of dispersal barriers are critical to quantify the degree of genetic exchange and to identify isolated populations (Bonato et al, 2018;Casal-López et al, 2018;Chung et al, 2005). This information is essential in designing effective habitat management and species conservation plans.…”