The ecological determinants of adaptive diversity in macroevolutionary radiations

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A major unanswered question in evolutionary biology is how ecological conditions, which often change over very short time intervals, can result in evolutionary patterns that are stable for millions of years. This question is difficult to address because it is not possible to conduct controlled experiments on processes that occur over macroevolutionary timescales. In my research, I will overcome this problem through careful investigation of a natural macroevolutionary experiment: replicated evolutionary radiations of tropical lizards in both island and mainland habitats. Anole lizards (genus Anolis) have independently diversified many times over tens of millions of years in both similar and different ecological settings. By treating each of these radiations as an individual replicate in a grand macroevolutionary experiment, I am able to test a wide variety of hypotheses about how ecology shapes the evolution of large-scale biodiversity.******For this work, my first objective will be to use genetic tools to reconstruct the phylogeny (i.e., the relationships and evolutionary history) of all ~400 species of anoles. My lab will then use this historical framework to test whether competing models of the macroevolutionary process can explain the resulting diversity of body forms that we observe in these lizards today. We will next focus on identifying the proximate factors that most influence macroevolution. Specifically, we will again use a phylogenetic framework to compare the relative importance of the geographic landscape versus the ecological community for generating adaptive diversity in organisms. For our final objective, we will investigate how the transport of exotic species by humans has altered fundamental diversity patterns in anoles, and we will seek to predict how, as a result of human activities, the future determinants of diversity will differ from those of the past.******The goal of this research is to advance our understanding of ecology and evolution by addressing a longstanding, unanswered question in evolutionary theory. This project will also have applied benefits for biodiversity conservation. Our work on introduced species will provide a general predictive framework for identifying trade-associated threats to species, and will be of value to stewards of biodiversity in Canada and worldwide.**