EAGER: Developing methods for evolutionary studies in a long-term ecological experiment

East Carolina University, Greenville NC

Investigators

Abstract

Evidence that evolutionary change can occur rapidly in response to altered environmental conditions requires that evolutionary processes be considered as causes for even short-term ecological change. This project will develop the methods needed to examine the roles of genetic variation and adaptation in plant community responses to changes in nutrient supply and disturbance. The project is based on a long-term ecological field manipulation; as changes in nutrient supply and the frequency of mowing cause changes in the abundance of individual species in the community, the potential exists for selection on traits affecting fitness. By developing methods to measure genetic change, the researchers will expand the current experiment to address two major ecological questions. First, do short-term ecological changes drive rapid evolutionary responses? Second, what role does genetic variation within and among species play in determining community diversity, composition, and responses to environmental change? The proposed research is both exploratory and risky. Undergraduate students will develop molecular markers without the benefits of a research laboratory where such work is routine. It remains unclear whether even strong selection caused by changing ecological conditions can result in genetic divergence in the face of gene flow among individuals and thus, one of the key questions upon which the proposal is based is risky. Finally, the extent to which genetic variation influences ecological processes, and particularly community assembly and the maintenance of diversity, is quite unknown, adding an additional risk to the proposed study. The project extends a long-term ecological experiment that was initiated to enhance ecology education for undergraduates at Eastern Carolina University and to provide students with authentic experiences in ecological research conducted at realistic spatial and temporal scales. The experiment serves as a unifying theme in the ECU biology curriculum, currently providing training in ecology, field methods, botany, experimental design and statistics. The proposed expansion of this experiment will generate new opportunities for undergraduate research and additional curriculum development. Students will carry out all of the proposed research to develop genetic markers and plant cultivation methods. A new project will expand the curriculum to include an undergraduate population genetics laboratory, using the long-term experiment as a research framework. The methods developed will contribute to future studies that extend beyond the long-term plots to address questions in evolutionary ecology in natural populations.