SG: Phenotypic plasticity and adaptation under rapid environmental change: Experimental evolution in a freshwater microbial eukaryote

Humans can cause rapid changes in the environment. How organisms respond to these changes remains an important question in environmental biology. Two types of biological change are likely in response to environmental change. First, individual organisms may undergo changes in behavior, physiology, or morphology, which will allow a rapid response. In the longer term, populations may undergo adaptive evolution, to create similar trait changes that allow them to persist in the new environment. By exposing populations of a microbe to two environmental pollutants in the lab and studying the short-term and long-term responses, this research will test how the two types of biological response interact to determine the fate of organisms experiencing rapid changes in their environment. This research will add to our understanding of biological responses to environmental change, while contributing to the training and education of a diverse student population. This project will provide mentored research experiences for graduate and undergraduate students who are from groups historically excluded from STEM, and will impact additional students through new course offerings. This research will study the plastic and adaptive responses of a freshwater microbial eukaryote, Tetrahymena thermophila, to two contaminants of their natural habitat, road salts and nanoparticle biocides. Measurements of organismal and gene-expression traits will be made before and after replicated experimental evolution in contaminated environments to assess the relationship between phenotypic plasticity and adaptive evolution. This research will provide valuable insight into how phenotypic plasticity and adaptive evolution affect one another, as well as how rapid environmental change affects both direct and correlated responses to selection. 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.