Speciation entails a reduction in gene flow between lineages. The rates at which genomic regions become isolated varies across space and time. Barrier markers are linked to putative genes involved in (processes of) reproductive isolation, and, when observed over two transects, indicate species-wide processes.
View Article and Find Full Text PDFGenomic data are increasingly used for high resolution population genetic studies including those at the forefront of biological conservation. A key methodological challenge is determining sequence similarity clustering thresholds for RADseq data when no reference genome is available. These thresholds define the maximum permitted divergence among allelic variants and the minimum divergence among putative paralogues and are central to downstream population genomic analyses.
View Article and Find Full Text PDFNewts of the genus Triturus (marbled and crested newts) exhibit substantial variation in the number of trunk vertebrae (NTV) and a higher NTV corresponds to a longer annual aquatic period. Because the Triturus phylogeny has thwarted resolution to date, the evolutionary history of NTV, annual aquatic period, and their potential coevolution has remained unclear. To resolve the phylogeny of Triturus, we generated a c.
View Article and Find Full Text PDFA critical consideration when using molecular ecological methods to detect trends and parameterize models at very fine spatial and temporal scales has always been the technical limits of resolution. Key landscape features, including most anthropogenic modifications, can cause biologically important, but very recent changes in gene flow that require substantial statistical power to detect. The problem is one of temporal scale: Human change is rapid and recent, while genetic changes accumulate slowly.
View Article and Find Full Text PDFGenomic data have the potential to inform high resolution landscape genetic and biological conservation studies that go far beyond recent mitochondrial and microsatellite analyses. We characterize the relationships of populations of the foothill yellow-legged frog, Rana boylii, a declining, "sentinel" species for stream ecosystems throughout its range in California and Oregon. We generated RADseq data and applied phylogenetic methods, hierarchical Bayesian clustering, PCA and population differentiation with admixture analyses to characterize spatial genetic structure across the species range.
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