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?
The argument for a Burmese origin for popcorn is strengthened by some habits of the Naga tribesmen which carry us back to the dispute over diffusion versus independent invention. These people, living in the Stone Age today, follow the agricultural pattern of the pre-Columbian Indian. They burn trees and underbrush to clear their fields. They use a digging stick to plant their corn in the charred rubbish. In amongst the corn they grow cereals and cotton.[31] On the other hand, they could have taken their corn to the New World long before the men of Bat Cave ate maize 6500 years ago.
Yet, if it should prove true that popcorn came to the Americas as the first form of maize, we should still have to credit the Indian with the tedious centuries—even millenniums—that went into the production of the many varieties which covered thousands of square miles of the New World when Columbus heard of “a sort of grain they call maiz.” And, before the coming of corn from Asia, we should still have to recognize the tens of centuries that went into the discovery and development of the agriculture of beans, squash, melons, potatoes, and manioc.
The story of corn and of agriculture does not tell us just when early man reached our hemisphere; but it suggests that he must have settled in South America thousands of years before the birth of Christ. He needed many millenniums to evolve from a hunting and gathering savage into a farmer and to reach the cultural level at which he would develop and perfect the many varieties of corn. These millenniums may stretch back to the last interglacial—if an astounding discovery in the Valley of Mexico can be accepted. According to Mangelsdorf, a drill core from more than 200 feet below ground contained fossilized grains of pollen. Elso Barghoom has identified them as corn. The geological level where the core was taken is “probably at least 80,000 years old.”[32]
12
PUZZLES, PROBLEMS, AND HALF-ANSWERS
One swallow does not make a summer, but two lead one to suspect an abiding change in the weather. —R. A. DALY