Evolutionary history of Scinax treefrogs on land-bridge islands in south-eastern Brazil

AIM: We investigated how Pleistocene refugia and recent (~12,000 years ago) sea level incursions shaped genetic differentiation in mainland and island populations of the Scinax perpusillus treefrog group. LOCATION: Brazilian Atlantic Forest, São Paulo state, southeastern Brazil. METHODS: Using mitochondrial and microsatellite loci, we surveyed population structure and genetic diversity in Scinax from five mainland populations and three land-bridge islands to understand the roles of Pleistocene forest fragmentation and sea level incursions on genetic differentiation. We calculated metrics of relatedness and genetic diversity to assess whether island populations exhibit signatures of genetic drift and isolation. Two of the three island populations in this study have previously been described as new species based on a combination of distinct morphological and behavioural characters, thus we used the molecular datasets to determine whether phenotypic change is consistent with genetic differ...