A new study published in Cell uncovers the deep evolutionary roots of flint and dent maize, commonly known as corn, two foundational varieties central to modern maize breeding and cultivation. Eighteen samples came from Ozark rockshelters and provide the first ancient maize DNA from east of the Rocky Mountains.
Gayle Fritz, a professor emerita of archaeology in WashU Arts & Sciences, was part of an international team of scientists that conducted this research.
Eastern North America represents one of the last stops in maize’s dispersion from its domestication center in southern Mexico. The path maize took to reach eastern North America has long been debated.
This study provides clear evidence that maize traveled across the Great Plains from the U.S. Southwest. By reconstructing the genomes of archaeological maize cobs and kernels, the study reveals that 1,000-year-old maize from rockshelters in the Ozark region of Arkansas shares a close genetic link with modern Northern Flint varieties.
It also shows that Indigenous farmers selected for a new starch synthesis pathway after maize left the Southwest, affecting the kernels’ texture and possibly taste, according to Fritz and her collaborators. New starch characteristics compatible with local food processing tools and cooking traditions might have been key to the dramatic increase in maize production in the Ozarks and eastern North America after CE 900.
Fritz, an expert on domestication and the spread of food production, provided archaeological context for the genomic analyses reported in the study.
