REPEATED EVOLUTION IN BLACK AND WHITE: DETERMINANTS OF CONVERGENCE IN WHITE SANDS LIZARDS

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In this time of rapid environmental change, it is more important than ever to understand how living things respond to shifting conditions. How quickly can species adapt to environmental change? Do different species respond to new conditions in similar ways? A powerful way to answer these questions is to look to the recent past. This project uses a striking example of rapid adaptation - where several species have adapted to the same environmental change - to study the predictability of evolution. The backdrop for the project is White Sands, a dramatic gypsum dune field in New Mexico. The dunes are geologically young, and the stark white sands contrast dramatically with the brown soil of the surrounding desert. Over the last few thousand years, a number of animal species have evolved blanched coloration to camouflage with the white habitat. This project focuses on comparing patterns of evolution in three desert lizard species, all of which have rapidly adapted to the extreme White Sands environment. By studying the genomes of the white sands lizards and their neighboring dark soil relatives - the researchers can understand how quickly - and how predictably - adaptation occurs in novel environments. White Sands provides an example of "evolution in action" - a case of evolutionary change over short, observable timescales. It also provides a setting for education and outreach. The researchers teach an annual "Lizard Camp" for local low-income middle school students and an annual "Biodiversity Day" for public school Kindergarteners, and work with a variety of schools, parks, and publishers to provide educational materials that instill a sense of wonder about biological diversity and the scientific process. This project contributes to understanding rules of how, and how predictably, genetic changes lead to changes in organismal traits that are important for the survival of species in natural and managed environments.It is often difficult to disentangle the contribution of different factors to adaptation in natural systems. However, White Sands offers replicated adaptation across multiple independent species, providing an opportunity to understand evolutionary predictability. The project applies an integrative genes-to-ecology approach to study the factors that determine the direction and magnitude of evolution in White Sands lizards. The project has three areas of investigation, focused on factors that influence whether species will exhibit a shared evolutionary response to changing conditions: natural selection, genomic architecture, and population demography. Mark-recapture studies will be used to quantify the strength of natural selection across species. Whole genome sequencing will be used to determine whether the genetic architecture of adaptive traits is parallel across species. Demographic modeling will be used to understand how gene flow affects phenotypic response across species. The approach explicitly integrates studies across multiple scales and methods in a single framework. Ultimately the research aims to reveal the factors that contribute to predictability of evolutionary change in the natural world.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.