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The Conundrum Of Corn
It’s our most important, profitable, and adaptable crop—the true American staple. But where did it come from?
August/September 1980 | Volume 31, Issue 5
This finality, however, did not impress other scientists. The Beadle school dismissed the Tehuacán wild corn as an early cultivated variety, since man was known to be farming by then. And they declared the dating of the old pollen to be highly suspect. They offered their own complex genetic data to prove that only a few minor mutations in teosinte, which was growing at least seven thousand years ago, would give it cornlike qualities. When that happened, they theorize, the Indians who collected teosinte seed as marginal food noticed the improved varieties and, one way or another, grew it for themselves. Gradually teosinte evolved into corn. Isn’t it odd, they ask the Mangelsdorf school, that ancestral strains of wheat, barley, and other grains still grow wild today but no one has ever found any wild corn? Isn’t it just as odd, retort their opponents, that no one has ever found any traces of teosinte at one of the stages it supposedly passed through while evolving into corn?
The arguments, far more subtle and hedged than this summary suggests, are made knottier by another relative of corn and teosinte: Tripsacum, sometimes called gama grass, which grows in many parts of the Americas. The late botanist Paul Weatherwax of Indiana University, studying the resemblances between the plants, deduced that all three descend from the same wild grass. Though his theory has less support—at least less vociferous support—than the others, it has not been altogether discarded.
Everything could be settled, of course, if someone could find a missing link between teosinte and corn, or some corn everyone agreed was wild. (Modern corn relies on man to survive. It cannot disperse its seed, and if an ear fell to the ground, the kernels would sprout into plants so numerous and close together that they would choke each other out.) In the 1960’s a squad of plant hunters mounted a botanical safari in Mexico to gather some seventy-five thousand samples of teosinte and look for evolutionary clues. But as Mangelsdorf gleefully saw it, it was a search “proving nothing scientifically but providing its participants with a memorable adventure.” Mangelsdorf himself, who admits that his lifetime spent in the study of one plant “can be regarded as a form of monomania,” undertook to create wild corn in his test plots. Trying to reverse evolution, he bred corn backwards, emphasizing its most primitive characteristics. He failed to reconstruct a wild species but he did wind up, as he put it, with “probably the world’s most unproductive corn.”
George Beadle, who won a Nobel Prize for his work in medicine and physiology, actually submitted his own digestive tract to support his pro-teosinte theory. Citing what he called “a friendly disagreement with Professor Mangelsdorf on the edibility” of teosinte, he undertook the Scrimshaw test. Following a regime devised for him by Dr. Nevin Scrimshaw, a nutritionist at the Massachusetts Institute of Technology, he set out to eat teosinte as prehistoric man would have: crushed seeds, hulls and all. After four days on this diet, the intrepid Nobel laureate announced that he suffered “no unpleasant consequences.”
Geologists and paleontologists have been on constant lookout for evidence of fossil corn. There was a furor some years ago when the Smithsonian Institution acquired a petrified ear of corn that had been unearthed in a curio shop in Cuzco. After some soul searching, the institution decided to analyze it rather than put it in a showcase. So the cob was dissected—and it turned out to be an ancient toy, a child’s rattle beautifully made of clay to imitate an ear of corn.
If the disciplines of modern science have been of no use in answering Kalm’s question, neither have the myths he discarded. While eastern Indians said a crow brought corn from the west, the Navahos said a turkey hen flew from the east and dropped a blue ear of corn. The Mayans believed their god-hero Gucumatz, knowing man needed corn, went through grievous perils to bring it to him. The Aztecs told that corn came from the western gardens of Tomoanchan, where goddesses lived, and was brought underground to the red land of dawn where the quetzal bird sings. The Abnaki Indians recited the tale of a lonesome brave who was visited by a lovely light-haired woman. She promised to be with him always if he would do as she said: “Rub two sticks together, burn a plot of grass and, when the sun goes down, take me by the hair and drag me over the ground. Grass will grow where I am dragged and hair will come up between the leaves.” Reluctantly the Indian did what she said, and so corn came to mankind—a lovely story but better perceived, perhaps, by Freudians than by farmers.