RESEARCH

My research seeks to uncover the ecological and evolutionary processes that have led to the staggering diversity of organisms that we see in Amazonia today. For that, I integrate genetic, environmental, and phenotypic data. I often study biodiversity in the context of climate and landscape gradients. I find comparative approaches to be powerful, so my projects target multiple populations and species.

My work uses biological inventories in the field, high-throughput DNA sequencing, bioinformatics, phylogenetics, population genetics, geospatial analyses, ecological niche estimation, and multivariate statistical techniques. I have focused on amphibians and reptiles as study organisms.

Learn more about my research projects below.




How have tropical species responded to former environmental change?


My research uses genomic-scale data to reconstruct the history of species and clades. Using population genetic and phylogenetic methods, I have studied how former climate and landscape shifts have affected the distribution and demography of tropical taxa.

This work has investigated population size shifts, range expansions, gene flow, and the timing of population coalescence in rainforest lizards (Anolis and Polychrus) and snakes (Bothrops).

This work has found that former climatic fluctuations fostered rainforest expansions and provided key opportunities for biotic interchange between Amazonia, the Atlantic Forest, and the Andes. Moreover, this research indicates that biological attributes shape species responses to environmental change.



How do environmental gradients shape genomic variation within and among species?


My research combines genetic, climate, and landscape data to help understand how ecological factors drive genomic variation. Based on genome-wide data, I have tested environmental correlates of allele frequency patterns, and identified genomic regions that have undergone selection.

I have sampled entire anole lizard (Anolis) assemblages in contrasting South American habitats to examine whether conspecific populations that occur in various environments exhibit genomic signatures of divergent selection.

This work has found strong associations between the frequency of alleles at several protein-coding loci with temperature and precipitation gradients in South America. These results support a role of local adaptation during range expansions across heterogeneous landscapes in widespread anoles.




Documenting tropical biodiversity and uncovering species' placement in the tree of life


Many species that occur in tropical rainforests remain unknown to science. Others have unclear phylogenetic affinities and geographic distributions. Through extensive fieldwork, I have sampled several poorly known taxa. I use genetic and phenotypic data to assess their phylogenetic relationships and taxonomic status, and to help outlining species ranges.

This work has provided taxonomic descriptions and insights into the morphological evolution and historical biogeography of Neotropical frog (Allobates) and lizard clades (Anolis, Neusticurus, Stenocercus). Ongoing work has focused on undescribed species of anole lizards and nurse frogs.



What drives the spatial variation of polymorphic traits within species?


Some species show remarkable levels of phenotypic variation among populations. I am interested in the historical and ecological factors underlying this pattern. My research combines multivariate statistical models and environmental, trait, and genetic data in a geospatial framework.

Building upon my Master's work, I have focused on the drivers of toxin composition variation within species of poison frogs (Dendrobatidae). Some species show 200+ distinct alkaloids, obtained from arthropod prey.

This work has recovered links between frog alkaloid composition turnover, population genetic structure, prey turnover, and environmental gradients.



Ivan Prates
ivanprates [at] gmail [dot] com
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