Phylogenetic diversity and North Andean block conservation.

Background: The Northern Andean Block (NAB) harbors high biodiversity; therefore, it is one of the most important areas in the Neotropics. Nevertheless, the settlement of several human populations has triggered the rapid transformation of ecosystems, leading to the extinction or endangerment of many species. Methods: Because phylogenetic diversity indices quantify the historical distinctness between species, they are adequate tools for evaluating priority conservation areas. We reconstructed 93 phylogenies encompassing 1,252 species and, utilizing their occurrence data sourced from the Global Biodiversity Information Facility, computed the Average Taxonomic Distinctness Index (AvTD) for each grid cell with a spatial resolution of 0.25° within the NAB. The index values for each grid cell were categorized into quantiles, and grid cells displaying values within the upper quantile (Q5) were identified as the most significant in terms of phylogenetic diversity. We also calculated the contribution of endemic species to overall phylogenetic diversity within the NAB, specifically focusing on areas preserved within protected areas. Results: The NAB Andean region exhibited the highest AvTD, with high AvTD values observed in the middle and southern areas of Cordilleras. Endemic species made a relatively modest contribution to the overall phylogenetic diversity of the NAB, accounting for only 1.2% of the total. Despite their relatively small geographical footprints, protected areas within the NAB have emerged as crucial repositories of biodiversity, encompassing 40% of the total phylogenetic diversity in the region. Discussion: Although the NAB Andean region has been identified as the most crucial area in terms of AvTD, some regions in the Amazonian Piedemonte and Pacific lowlands have high AvTD levels. Interestingly, some protected areas have been found to harbor higher AvTDs than expected, given their smaller size. Although the delimitation of new PAs and species richness have been the primary factors driving the expansion of PAs, it is also essential to consider the evolutionary information of species to conserve all aspects of biodiversity, or at least cover most of them. Therefore, using phylogenetic diversity measures and the results of this study can contribute to expanding the PA network and improving the connectivity between PAs. This approach will help conserve different aspects of biodiversity and preserve evolutionary relationships between species.

Systematics and phylogeography of bats of the genus Rhynchonycteris (Chiroptera: Emballonuridae): Integrating molecular phylogenetics, ecological niche modeling and morphometric data.

Rhynchonycteris is a monotypic genus of Embalonurid bats, whose geographic distribution extends from southern Mexico to tropical regions of the South American continent, including Trinidad and Tobago. Although species that have a wide geographic distribution are frequently revealed to be polytypic, to date, no study has evaluated the taxonomic status of populations of Rhynchonycteris naso. Thus, the aim of this study is to address the patterns of phylogeographic structure and taxonomic subdivision of R. naso using molecular phylogenetics, morphometric data and ecological niche modeling. Phylogenetic results recovered using the genes COI, Cytb, Chd1, Dby, and Usp9x, supported the monophyly of the genus Rhynchonycteris, in addition, a deep phylogeographic structure was revealed by the mitochondrial gene COI for the populations of Belize and Panama in comparison to those of South America. The PCA, and the linear morphometry indicated an apparent differentiation between the cis-Andean and trans-Andean populations. Furthermore, according to the skull morphology, at least two morphotypes were identified. Ecological niche modeling projections in the present have shown that the Andean cordillera acts as a climatic barrier between these two populations, with the depression of Yaracuy (Northwest Venezuela) being the only putative climatically suitable path that could communicate these two populations. On the other hand, projections for the last glacial maximum showed a drastic decrease in climatically suitable areas for the species, suggesting that cycles of lower temperatures played an important role in the separation of these populations.

Biogeographic evidence supports the Old Amazon hypothesis for the formation of the Amazon fluvial system.

The Amazon has high biodiversity, which has been attributed to different geological events such as the formation of rivers. The Old and Young Amazon hypotheses have been proposed regarding the date of the formation of the Amazon basin. Different studies of historical biogeography support the Young Amazon model, however, most studies use secondary calibrations or are performed at the population level, preventing evaluation of a possible older formation of the Amazon basin. Here, we evaluated the fit of molecular phylogenetic and biogeographic data to previous models regarding the age of formation of the Amazon fluvial system. We reconstructed time-calibrated molecular phylogenies through Bayesian inference for six taxa belonging to Amphibia, Aves, Insecta and Mammalia, using both, nuclear and mitochondrial DNA sequence data and fossils as calibration points, and explored priors for both data sources. We detected the most plausible vicariant barriers for each phylogeny and performed an ancestral reconstruction analysis using areas bounded by major Amazonian rivers, and therefore, evaluated the effect of different dispersal rates over time based on geological and biogeographical information. The majority of the genes analyzed fit a relaxed clock model. The log normal distribution fits better and leads to more precise age estimations than the exponential distribution. The data suggested that the first dispersals to the Amazon basin occurred to Western Amazonia from 16.2-10.4 Ma, and the taxa covered most of the areas of the Amazon basin between 12.2-6.2 Ma. Additionally, regardless of the method, we obtained evidence for two rivers: Tocantins and Madeira, acting as vicariant barriers. Given the molecular and biogeographical analyses, we found that some taxa were fitted to the "Old Amazon" model.

Sarcoptic mange in wild quichua porcupines (Coendou quichua Thomas, 1899) in Colombia.

The Quichua porcupine (Coendou quichua) is a neotropical rodent with uncertain taxonomic and conservation status. Two Quichua porcupines with severe hyperkeratosis and alopecia were found in the Magdalena River Basin of Colombia. Sarcoptes scabiei, the mite causing mange, a disease carried mainly by domestic animals, was confirmed via parasitological and molecular methods. This is the first report of mange in neotropical porcupines to date. The population-level impact of mange in Coendou spp., related mammals and predators in Colombia might represent a threat and needs further investigation.