Abstract
The Andes of South America hosts perhaps the highest amphibian species diversity in the world, and a sizable component of that diversity is comprised of direct-developing frogs of the genus Pristimantis (Anura: Craugastoridae). In order to better understand the initial stages of species formation in these frogs, this study quantified local-scale spatial genetic structuring in three species of Pristimantis. DNA sequences of two mitochondrial gene fragments (16S and COI) were obtained from P. brevifrons, P. palmeri and P. jubatus at different locations in the Cordillera Occidental. We found high levels of genetic diversity in the three species, with highly structured populations (as measured by F ST) in P. brevifrons and P. palmeri while P. jubatus showed panmixia. Large effective population sizes, inferred from the high levels of genetic diversity, were found in the three species and two highly divergent lineages were detected within P. jubatus and P. palmeri. Estimated divergence times among populations within P. brevifrons and P. palmeri coincide with the Pleistocene, perhaps due to similar responses to climatic cycling or recent geological history. Such insights have important implications for linking alpha and beta diversity, suggesting regional scale patterns may be associated with local scale processes in promoting differentiation among populations in the Andes.
Highlights
The Andes of South America contain the highest levels of total species richness in the world [1,2]
This study focused on three species of Pristimantis with distributions in the Cordillera Occidental of Colombia
MtDNA Diversity The 16S alignment contained 536 base pairs for P. brevifrons (N = 19 individuals), and 537 bp for P. palmeri (N = 32) and P. jubatus (N = 30). This locus showed the number of segregating sites, S = 18 for P. brevifrons, S = 12 for P. palmeri, and S = 26 for P. jubatus
Summary
The Andes of South America contain the highest levels of total species richness in the world [1,2]. The high biodiversity of tropical montane regions may be due to their old age [3], higher rates of adaptive divergence across elevation gradients [4,5], greater opportunities for vicariant speciation [6,7,8] or a mixture of factors [9,10]. The observation that sister species, at least in vertebrates, tend to be in similar habitats [8] suggests that simple vicariance models [12] could potentially account for much montane diversity compared with models invoking ecological gradients [5]. Mountain ridges and valleys have long been considered as agents of allopatric speciation by acting as effective barriers to dispersal [13]. Organismal biology and natural history interact with landscape features to determine to what extent a potential barrier will affect dispersal [6,14]. Even congeneric species may have contrasting ecological requirements that result in distinct phylogeographic histories [17]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
