Maize (Zea mays) is a plant of enormous modern-day economic importance as foodstuff and alternative energy source. Scholars agree maize was derived from the plant teosinte (Zea mays ssp. parviglumis) in central America perhaps as early as 7,500 years ago. In the Americas, maize is called corn, somewhat confusingly for the rest of the English-speaking world, where 'corn' refers to the seeds of any grain, including barley, wheat or rye.
The process of domesticating maize radically changed it from its origins. The seeds of wild teosinte are encased in hard shells and arranged on a spike with five to seven rows that shatter when ripe to disperse its seed. Modern maize has hundreds of exposed kernels attached to a cob which is completely covered by husks and cannot reproduce on its own. The morphological change is among the most divergent of speciation known on the planet, and it is only recent genetic studies that have proven the connection. The earliest undisputed domesticated maize is about 6250 years old, from Guilá Naquitz cave in Guerrero; it is possible that the process began as long as 7,500 years ago.
Theories of Maize Domestication
Two main theories as to the rise of maize have been promulgated. The teosinte model argues that maize is a genetic mutation direct from teosinte in the lowlands of Guatemala. The hybrid origin model states that maize originated in the Mexican highlands as a hybrid of diploid perennial teosinte and early-stage domesticated maize. Eubanks has suggested a parallel development within the Mesoamerican interaction sphere between lowland and highland. Recently starch grain evidence has been discovered in Panama suggesting the use of maize there by 7800-7000 cal BP, and the discovery of wild teosinte growing in the Balsas river region has lent support to that model.
The Spread of Maize
Eventually, maize spread out from Mexico, probably by the diffusion of seeds along trade networks rather than migration of people. It was used in the southwestern United States by about 3200 years ago, and in eastern United States beginning about 2100 years ago. DNA studies suggest that purposeful selection for various traits continued throughout this period, leading to the wide variety of species today. For example, 35 different races of maize have been identified in precolumbian Peru, including popcorns, flint varieties, and varieties for specific uses, such as chicha beer, textile dyes, and flour.
Artistic depictions of maize are known from various cultures, including Moche and Late Woodland ceramic objects. Archaeological sites of importance to the discussion of maize domestication include Guilá Naquitz and Coxcatlan caves in Mexico, and Newt Kash Hollow in the United States.
Sources
A brief bibliography of the domestication of maize has been created for this glossary entry.
This glossary entry is part of the Dictionary of Archaeology. Any mistakes are the responsibility of Kris Hirst.
