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.

1. 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.

I have tested population size shifts and range expansions and estimated the timing of population coalescence in co-distributed rainforest lizards (Anolis and Polychrus).

Results support that former climatic fluctuations fostered rainforest expansions and provided key opportunities for biotic interchange between Amazonia, the Atlantic Forest, and the Andean Yungas. They also suggest that biological attributes shape species-specific responses to environmental change.

2. 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 phenotypic and genomic variation. Based on genome-wide data, I am testing for environmental correlates of genomic variation, and identifying genomic regions that have undergone selection.

I have sampled entire anole lizard (Anolis) assemblages in contrasting South American ecosystems to examine whether conspecific populations that occur in diverse 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 across the distribution of co-distributed anole species.

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

Many species that occur in Amazonian 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 outline species ranges.

This work has provided new taxonomic descriptions and insights into the morphological evolution and historical biogeography of Neotropical lizard clades. Ongoing work focuses on undescribed species of anoles (Anolis) and dendrobatoid frogs (Allobates and Ameerega).

4. 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.

Ongoing analyses indicate links between frog alkaloid composition turnover, population genetic structure, prey (ant) turnover, and environmental gradients.

Ivan Prates
ivanprates [at] gmail [dot] com
© 2017 All Rights Reserved