Published online by Cambridge University Press: 25 January 2017
New evidence concerning the origin of maize — a question which has puzzled botanists for more than a century — has made it possible to reach several rather definite conclusions:
(1) Maize is undoubtedly an American plant.
(2) Maize undoubtedly had at least one center of origin in Middle America.
(3) The ancestor of maize is maize.
(4) The ancestor of maize is a form of pod corn, hut perhaps not the extreme type of pod corn known today. The ancestor was certainly a popcorn.
(5) Sometime in its history maize hybridized with Tripsacum or teosinte or both to produce radically new types which comprise the majority of modern maize varieties of North America.
The evidence on which these rather sweeping conclusions rest comes from three fields —botany, archaeology, and genetics.
Substantially conclusive evidence of the American origin of maize was obtained from fossil pollen grains discovered at a depth of more than 200 feet below Mexico City.