Amphibians and Reptiles Exhibit Different Ecological and Evolutionary Spatial Patterns in the Amazon Basin

Area of Science:

• Ecology and Evolutionary Biology
• Biodiversity Conservation
• Herpetology

Background:

• Spatial variability in ecological and evolutionary patterns is crucial for Amazonian biodiversity conservation.
• Understanding these patterns helps in identifying biodiversity hotspots and informing conservation strategies.

Purpose of the Study:

• To examine taxonomic, phylogenetic, and functional diversity of amphibians and reptiles across Amazon Basin ecoregions.
• To assess the influence of elevation on diversity metrics and explore interrelationships among them.
• To test the "cradle" (speciation) and "museum" (lineage preservation) hypotheses in the Amazon.

Main Methods:

• Analyzed 1011 amphibian and 828 reptile species using distribution maps, phylogenies, and trait data.
• Calculated taxonomic diversity (TD), phylogenetic diversity (PD), and functional diversity (FD).
• Computed mean phylogenetic distance to the nearest taxon (PD_mntd) and mean functional distance to the nearest taxon (FD_mntd).
• Performed spatial regressions with elevation and compared diversity metrics across five Amazon Basin ecoregions.

Main Results:

• Amphibian and reptile diversity patterns varied distinctly with elevation and across ecoregions.
• Anurans showed higher PD, FD, and TD in western Amazonia; squamates had hotspots at lower altitudes.
• Testudines were associated with major rivers, crocodilians with equatorial regions; Andean regions showed elevated PD_mntd and FD_mntd for anurans and squamates.

Conclusions:

• Eco-evolutionary patterns differ significantly among amphibian and reptile lineages in the Amazon Basin.
• Findings support the cradle-museum hypothesis, with regions acting as centers for speciation, lineage preservation, or both.
• Tailored conservation strategies are essential, recognizing the unique ecological and evolutionary dynamics of each taxon and ecoregion.