I am currently a postdoctoral fellow based in the laboratory of Dr. Ana Carnaval at The City College of New York. My research is interdisciplinary; merging techniques from ecology (e.g. habitat/population ecology, bio-geography, GIS), genetics (e.g. landscape genetics/genomics, population genetics), evolution (phylogenetics) and statistics.
The overarching goal of my research is to develop a conceptual framework for understanding the interplay between spatial, genetic, ecological and evolutionary processes. I integrate theoretical perspectives on evolution, ecology and population genetics with geospatial, field-based and molecular research to address fundamental questions about speciation, distribution patterns and the processes of generating and maintaining diversity. Most of my research falls into two focal areas:
• 1. Explicit integration of ecological, genetic and geospatial analyses to
address evolutionary and conservation questions — focusing on methodological and statistical issues
• 2. Behavioral ecology, evolution and systematics of South American poison frogs (family Dendrobatidae).
Explicit integration of ecological, evolutionary, genetic and geospatial analyses
Species are inherently connected to the environment in which they evolve. Much of my current research focuses on evaluating the genetic and demographic consequences of changes in habitat through time. One way I investigate this is to sample contemporary populations of terrestrial vertebrates with low dispersal potential and then sequence regions of mtDNA and nDNA for each sampled individual. I then couple species distribution models (SDMs), paleogeologic data and demographic models to emulate the colonization history of focal species. To examine the genetic consequences of the distributional shifts, coalescent genealogiesparameterized by the simulated demographic history are sampled for focal populations. Genetic simulations match conditions that correspond to empirical genetic data sets (e.g. population number and location, numberand length of genes to be simulated, substitution model, mutation and recombination rates of each gene). The integration of geospatial and genetic data also provides insights into the evolutionary mechanisms underlying recent divergences in ecology, phenotype and behavior (Brown et al. 2010 J. Biogeogr.; Brown & Knowles Mol. Ecol. 2012; Gehara, Brown et al. 2013 Evo. Ecol.).
Behavioral ecology, evolution and systematics of South American poison frogs (family Dendrobatidae)
As a doctoral researcher, I worked with Dr. Kyle Summers at East Carolina University. My dissertation research focused on evaluating key ecological and behavioral differences between two closely related species of Peruvian poison frogs (R. imitator and R. variabilis). These key differences were framed in the context of differing parental care strategies: R. imitator exhibits biparental care (where both parents take care of their tadpoles) and R. variabilis exhibits male parental care (where the males only partake in tadpole transport and deposition). I was particularly interested in the ecological and behavioral factors that contributed to the evolution of biparental care from male parental care ancestors. Over 6 years, I spent 18 months in the field observing these frogs, collecting data on their natural history, space use, home ranges, population structures, phytotelmata use, tadpole competition, tadpole growth rates and deposition strategies.
Throughout my studies I have been interested in decoding information within DNA that explains patterns of species distributions. Subsequently, I have spent considerable time working on projects associated with this topic. In particular, I am interested in the relationships between comparative phylogeographic patterns and mechanisms of speciation in poison frogs (family Dendrobatidae).
Another core of interest of mine is taxonomy, with a particular emphasis in clarifying alpha taxonomy for conservation purposes. We are in an era of unprecedented amphibian extinctions and the basic units of conservation are species. In order to adequately protect any species, we must first understand how many different species there are. This is particularly confusing for poison frogs, because most are extremely, morphologically conservative (with the exception of coloration). As a result, many sister taxa have limited, reliable morphological characters and thus, species boundaries are difficult to define. To address this problem we use phylogenetic analyses (molecular systematics), species distribution modeling, and traditional morphological methods. Finally, I am also interested in relationships between all these factors (i.e. sexual selection, evolution and maintenance of color and pattern polymorphism, mimicry selection, and phylogeography).