Barbara A. Ambrose is the Cullman Assistant Curator of Plant Genomics at The New York Botanical Garden, Bronx, New York, USA.Michael Purugganan is the Dorothy Schiff Professor of Genomics at the Department of Biology, Center for Genomics and Systems Biology, New York University, New York, USA, and at the Center for Genomics and Systems Biology, NYU Abu Dhabi Institute, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates.