My research group’s interests are at the interface between microbial evolution and synthetic biology. We study rates and mechanisms of genome evolution using laboratory populations of microbes, including in a >35-year experiment with Escherichia coli and using the naturally competent bacterium Acinetobacter baylyi. We investigate unwanted and unintentional evolution of DNA sequences in engineered cells so we can predict and prevent this uniquely biological failure mode. We develop open-source tools for analyzing bacterial genome resequencing data and annotating plasmids. Recently, we have also begun to engineer bacteria associated with insects in order to understand how new symbioses evolve and for applications, including protecting honey bee health.