Research
Overview
Because all organisms are related via evolution, it follows that disparities in biodiversity across both space (e.g., tropical versus temperate regions) and taxa (e.g., flowering plants versus conifers) result from differences in evolutionary time and/or rates. In other words, species richness, genetic diversity, and phenotypic diversity are inextricably linked to the balance of speciation and extinction rates, rates of molecular evolution, and rates of trait evolution, respectively. Thus, accurate estimation of evolutionary rates is absolutely essential to understanding and explaining the Earth’s uneven distribution of biodiversity.
In my research, I aim to develop new statistical tools for determining how evolutionary processes vary (especially in terms of rates) and the underyling factors that drive this variation. Unfortunately, between to the regularity of extinction and incompleteness of the fossil record (not to mention our short lifespans), estimating the rates of evolutionary processes is not straightforward. In my work, I use the phylogenetic comparative approach–essentially, using reconstructed phylogenies (i.e., evolutionary trees) and data from the relatively few living and/or fossilized organisms we can observe to make inferences about past evolutionary processes. Hopefully, these methods will ultimately help researchers understand the forces the shape the tree of life and structure the distribution of biodiversity across the globe.
Modeling variation in rates of continuous trait evolution
Rates of trait evolution vary markedly across the tree of life, from adaptive radiations to lineages of “living fossils”, but our tools for characterizing and analyzing this rate heterogeneity are still lacking in some cases. My current major research focus is developing novel models, approaches, and algorithms to address some of these gaps in the case of modeling continuous trait evolution.