Evaluating patterns of the evolution of thermal developmental plasticity in Anolis lizards
Developmental plasticity refers to the modification of phenotypes based on conditions experienced as embryos, and has lifelong consequences for organismal fitness. Temperature elicits plastic responses in embryos in many reptile species, however, little is known about how patterns of thermal developmental plasticity evolve across species on a macroevolutionary scale. I experimentally determined patterns of developmental plasticity in seven species of Anolis lizards inhabiting South Florida by incubating embryos of each species at a relatively cool versus relatively warm temperature treatment. I am using Bayesian mixed models to identify patterns in reaction norms within and among species, and identify potential drivers of the evolution of developmental plasticity in these invasive anoles. These results will also set a baseline for expected interspecific variation of thermal developmental reaction norms across this small sample of the Anolis genus.
Testing geography as a driver of the evolution of thermal developmental plasticity
Patterns of developmental plasticity in organisms are predicted to be driven by levels of environmental heterogeneity in occupied habitat. However, little is known about how quickly plasticity can evolve in response to changes in environmental heterogeneity. Green anoles (Anolis carolinensis) occupy a relatively broad climatic cline across the southeast United States, potentially facilitating intraspecific differences in patterns of thermal plasticity on the basis of environmental heterogeneity. I will experimentally determine patterns of thermal developmental plasticity among green anole populations spanning their native geographic range to determine whether different patterns of thermal developmental plasticity emerge on the basis of geography. This study will examine whether geographic variation (or lack thereof) in fitness-related phenotypes exhibits signatures of adaptive plasticity or natural selection toward climatically-driven optima.
Simulating rates of plasticity evolution
Developmental plasticity is a ubiquitous phenomenon among organisms and traits, and knowledge of the expected rates at which phenotype distributions in plasticity can change is useful for placing results of empirical studies in a broader evolutionary context. I am using SLiM 4 to construct allelic, individual-based simulations that assess the rate at which adaptive versus nonadaptive patterns of plasticity evolve within explicit population framework and variable environmental heterogeneity. These results will inform our expectations for interpreting the adaptive context of reaction norms gathered from wild populations in absence of fitness data.