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Evolution in the South American ‘Lost World’: insights from multilocus phylogeography of stefanias (Anura, Hemiphractidae, Stefania)

Journal Contribution - Journal Article

Aim: To investigate the influence of tepuian geomorphology on species diversi- fication in the Pantepui biogeographical region based on the phylogenetic rela- tionships and divergence times of tepui-endemic clades of stefania frogs (Stefania, Hemiphractidae).
Location: The ‘tepuis’ and uplands/lowlands of the Pantepui biogeographical region of northern South America, one of the least accessible and least studied areas in the world.
Methods: Two mitochondrial and two nuclear DNA sequences from 60 indi- viduals of Stefania from 24 localities in Pantepui were employed to infer phylo- genetic affinities and estimate divergence times within the genus using both concatenation and species tree analyses. Ancestral areas were inferred using multiple models in a common likelihood framework.
Results: Phylogenetic analyses revealed high diversity in the genus Stefania with 10 candidate species in the Eastern Pantepui District. Four strongly supported clades are recovered in the area, one being exclusively composed of microen- demics on isolated tepui summits. Biogeographical analyses suggest episodes of fragmentation of widespread tepuian ancestors from the onset of diversification of the genus, estimated in the Oligocene (c. 26 Ma), therefore suggesting a neglected vicariant model of Pantepui evolution, the Plateau Theory.
Main conclusions: Although our results suggest that vicariance played an important role in the diversification of Stefania, speciation in Pantepui fol- lowed an intricate pattern implying multiple nonexclusive processes. Vicariance and dispersal likely influenced diversification patterns of the Pantepui fauna, possibly according to the following sequence: (1) Cenozoic vicariance; (2) reor- ganization of species diversity due to periods of climatic instability; (3) recent invasions (Pleistocene) of widespread upland taxa.
Journal: Journal of Biogeography
ISSN: 0305-0270
Issue: 44
Pages: 170-181
Publication year:2016
Keywords:ancestral areas, anuran, dispersal, divergence times, frog, molecular phylogenetics, phylogeography, tepui, Venezuela, vicariance
CSS-citation score:2
Authors:International