Natural selection and other evolutionary forces leave characteristic signatures in the genetic variation within populations. The Desai lab uses a combination of theoretical and experimental approaches to study how this genetic variation is created and maintained, and to develop methods to infer the evolutionary history of populations from the variation observed in sequence data. The focus is primarily on natural selection in asexual populations such as microbes and viruses. The lab is developing new approaches to population genetic theory to better understand the structure of genetic variation in these populations. This research is complemented with high-throughput experimental evolution in budding yeast, the evolution of thousands of lines simultaneously exploring the distributions of phenotypic changes and their correlations with the evolution of genetic variation within and between populations. (modified from http://sysbiophd.harvard.edu/people/faculty/michael-desai)