Intellectual Merit: How organisms adapt to new environments is an important evolutionary question. Genome sequencing projects are currently discovering the genetic differences found in populations and between species. However, it is more difficult to determine which of these genetic changes cause adaptation and how. This project uses evolution of yeast populations in controlled laboratory conditions to watch evolution in action. By using new cheaper, faster sequencing methods, the genomes of evolved yeast strains can be decoded and compared to the ancestral founder cell. Discovered mutations can be engineered into new strains to test their effects alone and in combinations. These engineered strains will also be used to ask how mutations control which genes are active under the growth conditions. Finally, the project will repeat the evolution experiment multiple additional times to find how reproducible the results are. Results will allow discovery of what kinds of mutations are responsible for adaptation to new environments, how they lead to adaptive change, and how frequently the same genes acquire mutations if evolution is performed repeatedly. Due to the complexity of natural environments, simplified laboratory systems, like the one employed here, offer distinct advantages for testing these important questions.
Broader Impacts: This work will have a number of broader impacts in undergraduate and public science education, inclusion of underrepresented groups, and scientific understanding. Dr. Dunham has a strong record of educating undergraduates, including women, underrepresented minorities, and students from primarily undergraduate institutions. This research will allow more students to participate in substantive, independent research. Further understanding of evolutionary processes is a benefit to science and society. In particular, experimental demonstrations of evolution are a compelling example of evolutionary change in action. Understanding adaptation will also be useful to learning how to improve domesticated crops, animals, and microorganisms through selection.
