Grant King is interested in how novelty arises in the cell biology of eukaryotes. He studies a particular evolutionary innovation: the 2-micron plasmid in budding yeast, an extraordinarily stable extrachromosomal DNA element that has persisted in its hosts for millions of years. He investigates how yeast cells have evolved to accommodate, limit, and perhaps even benefit from this genomic passenger. His research will provide insight into the principles underpinning the development of new cellular features.