All the chief types of corn known today were developed by the Indians to suit the wide variety of lands and climates in which they lived. The feat seems all the more remarkable because botanists tell us that all these varieties had to be developed by keen observation and hard work from a single parent species—Zea mays L.—and modern man has never found corn in a wild form. This amazingly varied plant, which cannot properly seed itself and will die without man’s intervention, was evolved from a plant that is now apparently extinct.
In spite of the old saw about the staff of life, a starchy grain is not the ideal food; but corn, says Sauer, is the most useful of all American starches because in addition to its ease of storage “it contains also fat and protein and is a more nearly complete food than the others.”[18]
How Old Is Corn?
Obviously it must have taken many long years for the Indian to develop corn from its unknown ancestor into its many and widespread varieties. One botanical authority, G. N. Collins, thinks 20,000 years would not be enough—if a gross mutation, or sudden genetic change, were ruled out.[19] Other botanists do not accept such a figure. The development of corn may have taken a good many centuries or, more likely, a few millenniums. Behind corn must lie more centuries or more millenniums during which the first agriculturists of the New World discovered how to grow other plants, because whether corn originated in Middle America, Colombia, or Paraguay—independent inventionists argue for each locality—or in all three with the Mississippi Valley thrown in, there can be no question that it came later than most of the other cultivated plants. This adds still more years to the story of the civilizing of man in the Americas. Bruman writes:
Whether this high specialization of cultivated plant life can be used as an indication of greater age on the part of American agriculture in comparison to that of the Old World is a difficult point. In the writer’s opinion it may indicate merely a greater agricultural awareness on the part of the Indian, a cultural trait no doubt strongly furthered by the relative unimportance of domesticated animals.[20]
Corn of 4,500 years ago, as reconstructed from a cob found in Bat Cave, New Mexico. (After Mangelsdorf and Smith, 1949.)
Sylvanus G. Morley believed that the Maya cultivated corn at a time close to 1000 B.C.[21] which was, of course, no more than a guess. MacNeish states that the most ancient corn of the Maya area, found in the gulf state of Tamaulipas, dates from about 5,000 years ago.[22] We may presume that the Maya were cultivating it some centuries earlier. Antevs gives a date of “not later than 2500 B.C.” for a layer of refuse in Bat Cave, New Mexico, in which Herbert W. Dick found the cobs and kernels of a primitive form of maize that is both a pod corn and a pop corn. These cobs—now dated by radiocarbon at about 5,600 years ago[23]—range from 2⅜ inches to 3¾ inches in length. Though probably not specimens of the long-sought wild corn, they are not far removed in characteristics.[24] In coastal Peru—where corn could not have started—Julio C. Tello found kernels in the ruins of Paracas, along with manioc roots, sweet potatoes, and beans. There is a radiocarbon date of about 2,250 years ago for cotton cloth from a mummy found at Paracas.[25] In a preceramic culture about 5,000 years old,[26] Duncan Strong and Junius Bird found no corn, but evidence that these early agriculturists had raised cotton, squash, and other plants.[27]
It seems unlikely that any form of agriculture could have been developed from native plants in coastal Peru, for it is as arid a spot as can be found anywhere in our hemisphere. Only an elaborate system of irrigation canals enabled this area to grow extensively corn, beans, and other plants. In the highly developed civilization of the coast—so close to the guano islands—the Indians started the use of fertilizers, which was to be a feature of Peruvian agriculture. The development of irrigation and fertilizer, plus city architecture and the finest pottery in the Americas, spells many years of slowly growing civilization in coastal Peru, and behind these beginnings must have lain centuries upon centuries of earlier agricultural discoveries and improvements in the hinterlands. The only alternative is to accept the diffusion of a full-blown culture across the Pacific.
There are those who believe that corn did in fact come from Asia to the Americas. Sauer points out that Asia has more kinds of the wild grasses, Gramineae, akin to corn, Zea mays L., than the New World.[28] Another argument is that though the Chinese kept a careful record of the importation of various plants such as tobacco and the opium poppy, there is no mention of corn, implying that they had long been familiar with some variety of it.[29] The botanist Edgar Anderson believes it could have originated in Burma, and could have come across the Pacific “along with cotton, pottery, weaving, etc.”[30] Anderson’s evidence, as he himself maintains, is not conclusive; but it is certainly suggestive. Popcorn is found today among primitive or backward peoples in the remoter parts of Formosa, Sumatra, Java, Borneo, and Burma. From the Naga Hills, where Burma meets Assam, Anderson has had brought to the United States cobs and kernels of popcorn which are identical with the corn found in the earliest graves in Peru. Was this Burmese popcorn carried eastward over the Pacific thousands of years ago and then crossed with some American plant, such as Tripsacum, to produce the great variety of larger and more useful types that the Spaniards found? Or was popcorn, imported from the New World, the only maize that the primitive Naga of Burma would cultivate?