Phylogeographic structure suggests environmental gradient speciation in a montane frog from the northern Andes of Colombia

Allopatric speciation has been posed as the main mechanism affecting amphibian diversification. In contrast, the role of alternative mechanisms such as ecological speciation has received less attention, and empirical evidence of this mechanism in shaping species richness gradients remains elusive in the tropics. Highly heterogeneous landscapes can favor both allopatric and ecological speciation either by producing physical barriers to dispersal or by inducing selective pressures on lineages distributed along environmental gradients (e.g., climatic gradients). Based on explicit predictions under the ecological speciation hypothesis, we tested whether the phylogeographic, acoustic, morphological, and climatic features differ across the range of Pristimantis viejas, a frog species distributed along a wide altitudinal gradient in the northern Andes of Colombia. In agreement with our predictions, we found two highly differentiated lineages within P. viejas, showing striking differences in molecular diversity, acoustic, and climatic distribution. Importantly, we found that variation of such characteristics is highly congruent with variation in elevational ranges of these two lineages (P. viejas distributed in the lowlands and a cryptic sister lineage distributed in the highlands), and our evidence suggest that the divergence of these lineages was influenced by temperature-related variables. These results support a temperature-driven speciation process which may influence the amphibian diversity patterns in tropical mountains. Last, we describe and name the new cryptic lineage distributed in the highlands. We highlight that an integrative framework in phylogeographic studies should not only focuses on the identification of hidden lineages and their associated processes but also, when multiple lines of evidence are available, it should conduct to their formal description as species are the units for multiple biodiversity disciplines.

Variation in the coloration of the iris (photographs) and concealed surfaces of thighs (illustrations) of Pristimantis campesino sp. nov., a MHUA-A 11913, b MHUA-A 11734, c MHUA-A 8059, and d MHUA-A 8089; P. viejase MHUA-A 11261, f MHUA-A 9744, g MHUA-A 11468, and h MHUA-A 9759; and P. factiosusi MHUA-A 11736, j MHUA-A 11735, k MHUA-A 11732, and l MHUA-A 11736. Photos by Carlos M. Marin. Illustration by Ana M. Sepúlveda-Seguro

Get full article here: https://doi.org/10.1007/s13127-022-00549-9

A discovery journey to the Magdalena river

River turtle stories

To increase our knowledge on reproductive and movement of freshwater reptiles, in the second half of 2016 a project was initiated to study the “Home range and nesting ecology of the river turtle (Podocnemis lewyana) through the use of telemetry” within the middle Magdalena river region. Data was collected using telemetry techniques and home range and seasonal movements were quantified for the first time for the endemic species P. lewyana (Alzate-Estrada et al. 2020).

Podocnemis lewyana basking during the day. Photo: Viviana Cartagena.

Our history with this river turtle dates back to 2011, when the GHA started an environmental education and monitoring program of freshwater turtles and Spectacled caiman (caimán de anteojos) in four streams located in the middle Magdalena area near to the towns of Puerto Berrio in Antioquia and Carare in Santander.


Tracking babillas (Caiman crocodilus) in tributaries of the Magdalena river in department of Santander. Photo: Viviana Cartagena.

During this time, valuable ecological and demographic information was collected on the river turtle allowing us to categorize the species as critically endangered (CR) according to IUCN categories (Morales-Betancourt et al. 2015). Demographic information and life hisotry data was also published (Páez et al. 2015).

Tracking an individual of Podocnemis lewyana through the Magdalena river. Photo: Diego Alzate

The story continues and we hope to add more information in the near future aiming to make better conservation decisions for this wonderful but highly threatened Magdalena treasure.

This video is part of an ongoing project the GHA is leading in western Antioquia to study and preserve natural populations of the Magdalena river turtle Podocnemis lewyana

 

Congratulations!!!

We have new biologists in the Lab!! Congratulations to Ana, Marley, Yuly and Wilmar and thanks a lot for being part of the GHA. Los mejores deseos en sus carreras!!!

 

20th anniversary