Angiosperm Evolution and Diversification Within Adaptive Zones (Visiting Scholar)
Understanding the dynamics of diversification and trait evolution through time is a central goal of evolutionary biology. One common conceptual framework is that radiations occur within “adaptive zones”, distinct regions of ecological niche space that facilitate adaptive radiations (Simpson 1944). Despite continued interest in adaptive zones, there are still no comparative phylogenetic studies that evaluate whether such adaptive zones exist. In this project, I aim to extend existing comparative statistical approaches (e.g. Eastman et al. 2011) to directly test for the effects of shifts between adaptive zones over macroevolutionary time scales. I will implement a model that allows for discrete “jumps” in trait space that would be the signature of transitions between adaptive zones, and compared this model to common alternatives (e.g. Harmon et al. 2010) in a model-selection framework. I will then apply this approach to the extraordinary radiation of angiosperms, and analyze a recently built phylogeny of the angiosperms along with an extensive database of ecological traits that were constructed as part of the “Tempo and Mode of Plant Trait Evolution” NESCent working group.