Dragan Stajic, Claudia Bank

In this book chapter, we discuss the importance of phenotypic switching with respect to adaptation. Hereby, we focus on epigenetic mechanisms of phenotypic switching that are involved in gene expression regulation. We start by placing the discovery of phenotypic switching in the context of the history of evolutionary biology. We highlight how the controversy about whether phenotypic switching can contribute to adaptation arose. We then present a non-exhaustive list of examples of epigenetic phenotypic switching in nature. Finally, we discuss several evolutionary hypotheses about the role of phenotypic switching in adaptation to new and fluctuating environments, and give examples of how these hypotheses have been addressed experimentally.