An ancient origin of the naked grains of maize

Abstract

The domestication of plants not only transformed human societies by giving rise to agriculture, but also often transformed the plants themselves. During maize domestication the tough, stony fruitcase that encloses kernels of the wild relatives was lost, leaving fully exposed, edible kernels in maize. The evolution of this trait was long thought to have required a new mutation arising in already cultivated populations. Our study contravenes a half century of previous work, demonstrating that this key development instead leveraged preexisting variation in the wild. This contributes to growing evidence for an important role for standing genetic variation not only in maize domestication, where maize adapted to novel anthropogenic environments, but also in adaptation more generally.