Surprising History of Maize Domestication

Smithsonian scientists and collaborators are revising the history of one of the world's most important crops. Drawing on genetic and archaeological evidence, researchers have found that a predecessor of today's corn plants still bearing many features of its wild ancestor was likely brought to South America from Mexico more than 6,500 years ago. Farmers in Mexico and the southwestern Amazon continued to improve the crop over thousands of years until it was fully domesticated in each region. The findings, reported Dec. 13 in the journal Science, come from a multidisciplinary, international collaboration between scientists at 14 institutions. Their account deepens researchers' understanding of the long, shared history between humans and maize, which is critical for managing our fragile relationships with the plants that feed us, said Logan Kistler, curator of archaeogenomics and archaeobotany at the Smithsonian's National Museum of Natural History and lead author of the study. "It's the long-term evolutionary history of domesticated plants that makes them fit for the human environment today," he said. "Understanding that history gives us tools for assessing the future of corn as we continue to drastically reshape our global environment and increase our agricultural demands on land around the globe." The history of maize begins with its wild ancestor, teosinte. Teosinte bears little resemblance to the corn eaten today: Its cobs are tiny and its few kernels are protected by a nearly impenetrable outer casing. In fact, Kistler said, it's not clear why people bothered with it all. Over time, however, as early farmers selected for desirable traits, the descendants of the wild plant developed larger cobs and more tender, plentiful kernels, eventually becoming the staple crop that maize is today. (Source: Agriculture and Food News, ScienceDaily. www.sciencedaily.com)