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Serrano, F. C.

Publications and source records attributed to Serrano, F. C..

2 recordsLinked to original sources

There and back again: when and how the world's richest snake family (Dipsadidae) dispersed and speciated across the Neotropical region

AimThe widespread megadiverse Neotropical snake family Dipsadidae occurs in a large range of diverse habitats. Thus it represents an excellent model to study the diversification of Neotropical biota. Herein, by generating a time-calibrated species-level phylogeny, we investigate the origin and historical biogeography of Dipsadidae and test if its two main Neotropical subfamilies, Xenodontinae and Dipsadinae, have different geographical origins. LocationNeotropical region. TaxonDipsadidae (Serpentes). MethodsWe generated a new Bayesian time-calibrated phylogeny including sequences from six genes for 344 species, including 287 species of Dipsadidae. We subsequently estimated ancestral areas of distribution by comparing models in BioGeoBEARS: DEC (subset sympatry, narrow vicariance), DIVALIKE (narrow and wide vicariance), BAYAREALIKE (no vicariance and widespread sympatry), also testing jump dispersal. ResultsThe best models show that Dipsadidae likely originated approximately 50 million years ago (mya) in Asia. Dispersal was a fundamental process in its historical biogeography. The DEC model with jump dispersal indicated that this family underwent a range extension from Asia and posterior vicariance of North and Central America ancestors. Both Xenodontinae and Dipsadinae originated in Central America and dispersed to South America during Middle Eocene, but did so to different regions (cis and trans-Andean South America, respectively). Xenodontinae entered cis-Andean South America around 39 mya and jump dispersed to the West Indies around 33 mya, while Dipsadinae entered trans-Andean South America multiple times 20 - 38 mya. Main conclusionsOur results show that Dipsadidae has an Asian origin and that the two main Neotropical subfamilies originated in Central America, later dispersing to South America in different time periods. The current biogeographical patterns of the family Dipsadidae, the most species-rich snake family in the world, have likely been shaped by complex evolutionary and geological processes such as Eocene land bridges, Andean uplift and the formation of the Panama isthmus.

ecology↗

Behavioral thermal tolerance predicts distribution pattern but not habitat use in sympatric Neotropical frogs

Environmental temperatures are a major constraint on ectotherm abundance and diversity, influencing their distribution and natural history. Comparing thermal tolerances with environmental temperatures is a simple way to estimate thermal constraints on species distributions. We investigate the potential effects of thermal tolerance on anuran local (habitat) and global distribution patterns and associated behavioral responses. We tested for differences in Voluntary Thermal Maximum of two sympatric frog species of the genus Physalaemus in the Cerrado ecoregion. For each species, we constructed models to assess the effects of period of day, duration of experiment, initial body mass, initial body temperature and heating rate on the VTMax. We mapped the difference between VTMax and maximum daily temperature (VTMax - ETMax) for each occurrence point. Physalaemus nattereri had a significantly higher VTMax than P. cuvieri. For P. nattereri, the model including only period of day was chosen as the best to explain variation in the VTMax. For P. cuvieri, no model was selected as best to predict VTMax. The VTMax - ETMax values were significantly different between species, with P. nattereri mostly found in localities that attain maximum temperatures lower than its VTMax and P. cuvieri showing the reverse pattern. Regarding habitat use, we found P. cuvieri to be slightly more abundant in open habitats than in non-open habitats, whereas P. nattereri shows the reverse pattern. The difference in VTMax values between these two species might be related to their different body sizes, but additionally might reflect their natural history, especially the way they use their habitats, and phylogenetic constraints (the species studied are in different clades within Physalaemus). Our study indicates that differences in behavioral thermal tolerance may be important in shaping local and regional distribution patterns. Furthermore, small-scale habitat use might reveal a link between behavioral thermal tolerance and natural history strategies.

ecology↗