Professor Townsend received his Ph.D. in 2002 in organismic and evolutionary biology from Harvard University, under the advisement of Daniel Hartl. His Ph.D. was entitled "Population genetic variation in genome-wide gene expression: modeling, measurement, and analysis", and constituted the first population genetic analysis of genome-wide gene expression variation. After making use of the model budding yeast S. cerevisiae for his Ph.D. research, Dr. Townsend accepted an appointment as a Miller Fellow at the University of California-Berkeley in the Department of Plant and Microbial Biology, where he worked to develop molecular tools, techniques, and analysis methodologies for functional genomics studies with the filamentous fungal model species Neurospora crassa, co-advised by Berkeley fungal evolutionary biologist John Taylor and molecular mycologist Louise Glass. In 2004, he accepted his first appointment as an Assistant Professor in the Department of Molecular and Cell Biology at the University of Connecticut. In 2006 he was appointed as an Assistant Professor the Department of Ecology and Evolutionary Biology at Yale University. In 2013 he began to work on statistical approaches to fit mathematical models of disease spread and emergence, and to work on the somatic evolution of cancer, and was appointed as an Associate Professor of Biostatistics and Ecology & Evolutionary Biology. In 2017 he was named Elihu Associate Professor of Biostatistics and Ecology & Evolutionary Biology, and in 2018 he was appointed Elihu Professor of Biostatistics and Ecology & Evolutionary Biology. In 2019 he was appointed a member of the Connecticut Academy of Science and Engineering, in recognition of the development of innovative approaches to population biology, including the evolution of antimicrobial resistance, disease evolution and transmission, and evolution of tumorigenesis; and research that has enabled curtailment of pathogen evolution, outbreak mitigation, and informed therapeutic approaches to cancer metastasis and evolution of therapeutic resistance in cancer. In 2021 he was selected as the Co-Chair-Elect of the Cancer Evolution Working Group of the American Association for Cancer Research. In 2022 he was appointed Co-Director of the Genetics, Genomics, and Epigenetics Program of the Yale Cancer Center. In 2023 he was elevated to Co-Chair of the Cancer Evolution Working Group of the American Association for Cancer Research.