John F. Doebley is an American botanical geneticist whose main area of interest is how genes drive plant development and evolution. He has spent the last two decades examining the genetic differences and similarities between teosinte and maize and has cloned the major genes that cause the visible differences between these two very different plants. He was part of the team that is credited with first finding, back in 2002, that maize had been domesticated only once, about 9000 years ago, and then spread throughout the Americas.