Indian farmers grow maize in what is called a milpa. The term means “maize field,” but refers to something considerably more complex. A milpa is a field, usually but not always recently cleared, in which farmers plant a dozen crops at once, including maize, avocados, multiple varieties of squash and bean, melon, tomatoes, chilis, sweet potato, jicama (a tuber), amaranth (a grain-like plant), and mucuna (a tropical legume). In nature, wild beans and squash often grow in the same field as teosinte, the beans using the tall teosinte as a ladder to climb toward the sun; below ground, the beans’ nitrogen-fixing roots provide nutrients needed by teosinte. The milpa is an elaboration of this natural situation, unlike ordinary farms, which involve single-crop expanses of a sort rarely observed in unplowed landscapes.

  Milpa crops are nutritionally and environmentally complementary. Maize lacks digestible niacin, the amino acids lysine and tryptophan, necessary to make proteins and diets with too much maize can lead to protein deficiency and pellagra, a disease caused by lack of niacin. Beans have both lysine and tryptophan, but not the amino acids cysteine and methionine, which are provided by maize. As a result, beans and maize make a nutritionally complete meal. Squashes, for their part, provide an array of vitamins; avocados, fats. The milpa, in the estimation of H. Garrison Wilkes, a maize researcher at the University of Massachusetts in Boston, “is one of the most successful human inventions ever created.”

  Wilkes was referring to the ecological worries that beset modern agribusiness. Because agricultural fields are less diverse than natural ecosystems, they cannot perform all their functions. As a result, farm soils can rapidly become exhausted. In Europe and Asia, farmers try to avoid stressing the soil by rotating crops; they may plant wheat one year, legumes the next, and let the field lie fallow in the year following. But in many places this only works for a while, or it is economically unfeasible not to use the land for a year. Then farmers use artificial fertilizer, which at best is expensive, and at worst may inflict long-term damage on the soil. No one knows how long the system can continue. The milpa, by contrast, has a long record of success. “There are places in Mesoamerica that have been continuously cultivated for four thousand years and are still productive,” Wilkes told me. “The milpa is the only system that permits that kind of long-term use.” Likely the milpa cannot be replicated on an industrial scale. But by studying its essential features, researchers may be able to smooth the rough ecological edges of conventional agriculture. “Mesoamerica still has much to teach us,” Wilkes said.

  To Wilkes’s way of thinking, ancient Indian farming methods may be the cure for some of modern agriculture’s ailments. Beginning in the 1950s, scientists developed hybrid strains of wheat, rice, maize, and other crops that were vastly more productive than traditional varieties. The combination of the new crops and the greatly increased use of artificial fertilizer and irrigation led to the well-known Green Revolution. In many ways, the Green Revolution was a tremendous boon; harvests in many poor countries soared so fast that despite burgeoning populations the incidence of hunger fell dramatically. Unfortunately, though, the new hybrids are almost always more vulnerable to disease and insects than older varieties. In addition to being too costly for many small farmers, the fertilizer and irrigation can, if used improperly, damage the soil. Worst, perhaps, in the long run, the exuberant spread of the Green Revolution has pushed many traditional cultivars toward extinction, which in turn reduces the genetic diversity of crops. Wilkes believes that some or all of these difficulties may be resolved by reproducing features of the milpa in a contemporary setting. If this occurs, it will be the second time that the dissemination of Mesoamerican agricultural techniques will have had an enormous cultural impact—the first time being, of course, when they originated.

  From today’s vantage it is difficult to imagine the impact maize must have had in southern Mexico at the beginning, but perhaps a comparison will help. “Almost pure stands” of einkorn wheat covered “dozens of square kilometers” in Turkey, Iraq, Syria, and other parts of the Middle East, according to Jack R. Harlan and Daniel Zohary, two agronomists who pored over the area in the 1960s to determine the distribution of wild cereals. “Over many thousands of hectares” in those countries, they wrote in Science, “it would be possible to harvest wild wheat today from natural stands almost as dense as a cultivated wheat field.” In the Middle East, therefore, the impact of agriculture was thus less a matter of raising the productivity of wheat, barley, and other cereals than of extending the range in which they could be grown, by developing varieties that could flourish in climates and soils that daunt the wild plant. By contrast, the Americas had no wild maize, and thus no wild maize harvest. Stands of teosinte have been seen in the wild, but because the “ears” are tiny and constantly shattering they are difficult to harvest. Thus before agriculture the people of Mesoamerica had never experienced what it was like to stand in a field of grain. Grain fields—landscapes of food!—were part of the mental furniture of people in Mesopotamia. They were an astounding novelty in Mesoamerica. Indians not only created a new species, they created a new environment to put it in. Unsurprisingly, the reverberations sounded for centuries.

  Maize in the milpa, the Yale archaeologist Michael D. Coe wrote, “is the key … to the understanding of Mesoamerican civilization. Where it flourished, so did high culture.” The statement may be more precise than it seems. In the 1970s the geographer Anne Kirkby discovered that Indian farmers in Oaxaca considered it not worth their while to clear and plant a milpa unless it could produce more than about two hundred pounds of grain per acre. Using this figure, Kirkby went back to the ancient cobs excavated from Tehuacán Valley and tried to estimate how much grain per acre they would have yielded. The cob sizes steadily increased as they approached the present. In Kirkby’s calculation, the harvest broke the magic two-hundred-pound line sometime between 2000 and 1500 B.C. At about that time, the first evidence of large-scale land clearing for milpas appears in the archaeological record. And with it appeared the Olmec, Mesoamerica’s first great civilization.

  Based on the Gulf Coast side of Mexico’s waist, on the other side of a range of low mountains from Oaxaca, the Olmec clearly understood the profound changes wreaked by maize—indeed, they fêted them in their art. Like the stained-glass windows in European cathedrals, the massive Olmec sculptures and bas-reliefs were meant both to dazzle and instruct. A major lesson is the central place of maize, usually represented by a vertical ear with two leaves falling to the side, a talismanic symbol reminiscent of a fleur-de-lys. In sculpture after sculpture, ears of maize spring like thoughts from the skulls of supernatural beings. Olmec portraits of living rulers were often engraved on stelae (long, flat stones mounted vertically in the ground and carved on the face with images and writing). In these stela portraits, the king’s clothes, chosen to represent his critical spiritual role in the society’s prosperity, generally included a headdress with an ear of maize emblazoned on the front like a star. So resonant was the symbol, according to Virginia M. Fields, curator of pre-Columbian art at the Los Angeles County Museum of Art, that in later Maya hieroglyphics “it became the semantic equivalent of the highest royal title, ahaw.” In the Maya creation story, the famous Popul Vuh, humans were literally created from maize.

  Maize and the milpa slowly radiated throughout the Americas, stopping their advance only where the climate grew too cold or dry. By the time of the Pilgrims, fields of mixed maize, beans, and squash lined the New England coast and in many places extended for miles into the interior. To the south, maize reached to Peru and Chile. Maize was a high-status food there even though Andean cultures had developed their own agricultural system, with potatoes occupying the central role. (Amazonia seems to have been an exception; most but not all researchers believe maize there was eclipsed by manioc.)

  Maize had an equivalent impact on much of the rest of the world after Columbus introduced it to Europe. Central Europeans became especially hooked on it; by the nineteenth century, maize w
as the daily bread of Serbia, Rumania, and Moldavia. So dependent did northern Italy and southwestern France become on polenta, a type of cornmeal mush, that pellagra (caused by eating too much maize) became widespread. “I know little, if anything, pleasing to say about the people,” wrote Goethe, who visited northern Italy in 1786. The women’s “features indicated misery, and the children were just as pitiful to behold; the men are little better.… The cause of this sickly condition is found in the continued use of Turkish and heath corn.”

  Even greater was the impact in Africa, where maize was transforming agriculture by the end of the sixteenth century. “The probability is that the population of Africa was greatly increased because of maize and other American Indian crops,” Alfred Crosby told me. “Those extra people helped make the slave trade possible.” (“Other American Indian crops” included peanuts and manioc, both now African staples.) Maize swept into Africa as introduced disease was leveling Indian societies. Faced with a labor shortage, the Europeans turned their eyes to Africa. The continent’s quarrelsome societies helped them siphon off millions of people. The maize-fed population boom, Crosby believes, let the awful trade continue without pumping the well dry.

  THE STUPIDEST QUESTION IN THE WORLD

  A few days after I met Ramírez Leyva, the tortilla entrepreneur, we went to Soledad Aguablanca, a clump of small farms two hours southeast of Oaxaca City. Waiting for us at the side of the road was Héctor Díaz Castellano, one of the farmers who supplied Ramírez Leyva’s store. Díaz Castellano had a pencil moustache and a rakish straw hat. His Spanish was so heavily salted with Zapotec, the language of Oaxaca’s biggest Indian group, that I could not make out a word of it; Ramírez Leyva had to translate. The maize field was at the end of a long, rutted dirt road that led up a rise. Although we had left just after dawn, the sun was hot enough by our arrival to make me wish for a hat. Díaz Castellano walked along the rows, his gaze taking in every stalk as he passed. For an hour he spoke, almost without stopping, about his maize and the market for his maize. He was not, I suspected, a naturally loquacious man, but that morning he had a subject that interested him.

  Héctor Díaz Castellano

  (Illustration Credit 6.6)

  Díaz Castellano’s maize field was one of the 340,000 farms in Oaxaca. His farm, like about two-thirds of the farms in the state, occupied less than ten acres—unviably small by the standards of developed nations. Most landrace maize is grown on these farms, partly because of tradition and partly because they are usually in areas that are too high, dry, steep, or exhausted to support high-yield varieties (or owned by farmers too poor to afford the necessary fertilizer). As if being grown on tiny farms in bad conditions weren’t enough, landrace maize is usually less productive than modern hybrids; a typical yield is .4 to .8 tons per acre, whereas Green Revolution varieties in Oaxaca reap between 1.2 and 2.5 tons per acre when properly fertilized, a crippling advantage. The meager harvests may be enough for subsistence but can rarely be brought to market because farm villages are often hours away on dirt roads from the nearest large town. But even when farmers try, it is often little use: modern hybrids are so productive that despite the distances involved U.S. corporations can sell maize for less in Oaxaca than can Díaz Castellano. Landrace maize, he said, tastes better, but it is hard to find a way to make the quality pay off. He was lucky, he said, that Ramírez Leyva was trying to market his crop.

  We went to Díaz Castellano’s house for breakfast. His wife, Angelina, round and short-haired in a tight plaid dress, was cooking tortillas in an outdoor shed with corrugated aluminum walls. A wood fire burned beneath a concave clay griddle called a comal. The comal was propped above the flames on three rocks—a cooking method as old as Mesoamerican culture. By the fire, in a three-legged stone bowl, was a lump of fresh masa twice the size of a toaster. The stereotype is that rural Mexicans are generous to strangers. Piling my plate high, Angelina did nothing to dispel this impression.

  I asked her husband what he was. I had wanted to find out which Indian group he was born into, but he took the question another way.

  “Somos hombres de maíz,” he said, enunciating clearly for my benefit. We are men of maize.

  I wasn’t sure what to make of this gnomic utterance. Was he pulling my leg?

  “Everybody says that,” Ramírez Leyva said, observing my confusion. “It’s an idiom.” A little while later I visited a Danish anthropologist at the International Maize and Wheat Improvement Center (CIMMYT), outside Mexico City. Watching films of her interviews with Oaxacans, I saw two old women explain to the young anthropologist that they, too, were hombres de maíz. So Ramírez Leyva was right, I thought. A day later a CIMMYT biologist gave me a paperback book, describing it as “the best novel ever written about Mesoamerica.” It was Hombres de maíz, by Miguel Angel Asturias. All right already, I thought. I get it.

  Meanwhile Angelina had come out from behind the comal and joined her husband. In the Oaxacan countryside, they explained to me, a house without maize growing in the backyard is like a house without a roof or walls. You would never not have maize, they said. They were speaking matter-of-factly, as if telling me how to take the bus. Even in the city, they said, where people cannot grow maize, nobody would even think of passing a day without eating it.

  Curious, I asked what they thought would happen if they didn’t have maize every day. Díaz Castellano looked at me as if I had asked the stupidest question in the world.

  “Why should I want to be somebody else?” he said.

  *I am not criticizing McNeill for failing to include the Americas on his list of civilizations; he was simply reflecting the beliefs of his time. I would criticize World History: Patterns of Change and Continuity, a high school text published two decades later, in time for my son to encounter it. Referring exclusively to the “four initial centers” of civilization, this “world history” allocated just nine pages to the pre-Columbian Americas. The thesis of the book in your hands is that Native American history merits more than nine pages.

  *Given the choice between their own scratchy wool and the Indians’ smooth cotton, the conquistadors threw away their clothes and donned native clothing. Later this preference was mirrored in Europe. When cotton became readily available there in the eighteenth century, it grabbed so much of the textile market that French woolmakers persuaded the government to ban the new fiber. The law failed to stem the cotton tide. As the historian Fernand Braudel noted, some woolmakers then thought outside the box: they proposed sending prostitutes in cotton clothing to wander Paris streets, where police would publicly strip them naked. In theory, bourgeois women would then avoid cotton for fear of being mistaken for prostitutes and forcibly disrobed. This novel form of protectionism was never put into place.

  7

  Writing, Wheels, and Bucket Brigades

  (Tales of Two Civilizations, Part II)

  “LIKE GRAPES THEY FALL OFF”

  On January 16, 1939, Matthew W. Stirling took an early-morning walk through the wet, buggy forest of Veracruz state, on the Gulf Coast side of Mexico’s southern isthmus. Eighty years before his walk, a villager traipsing through the same woods had stumbled across a buried, six-foot-tall stone sculpture of a human head. Although the find was of obvious archaeological importance, the object was so big and heavy that in the intervening eight decades it had never been pulled out of the ground. Stirling, director of the Smithsonian Bureau of American Ethnology, had gone to Mexico the year before, in early 1938, to see the head for himself. He found it, sunk to the eyebrows in mud, after an eight-hour horseback ride from the nearest town. The head was in the midst of about fifty large, artificial earthen mounds—the ruins, Sterling concluded with excitement, of a previously unknown Maya civic center. He had decided to assemble a research team and explore the area in more detail the next year, and persuaded the National Geographic Society to foot the bill. When he returned to Veracruz, he and his team cleared the dirt around the great head, admiring its fine, naturalistic workmansh
ip, so unlike the stiff, stylized sculpture common elsewhere in Mesoamerica. Nearby, they found a stela, its wide, flat face covered with bas-relief figures. Hoping to turn up others, Stirling was walking that January morning to the far end of the mounded area, where a workman had noticed a large, flat, partly submerged rock: a second stela.

  Accompanying him were twelve workers from the nearby hamlet of Tres Zapotes. They pried the stela from the ground with wooden poles, but it was blank. Disappointed, Stirling took the crew to yet a third fallen stela. They scraped away the covering dirt and found that it, like the first, was covered with intricate images. Alas, the carvings were now too weathered to be deciphered. The frustrated Stirling asked the workers to expose the back of the slab by digging beneath it and levering up the stone with poles. Several of the men, he later recounted, “were on their knees in the excavation, cleaning the mud from the stone with their hands, when one of them spoke up in Spanish: ‘Chief! Here are numbers!’ ”

  Across the back of the stela were clumps of dots and bars, a notation familiar to Stirling from the Maya. The Maya used a dot to signify one and a horizontal bar to signify five; the number nineteen would thus be three bars and four dots. Stirling copied the dots and bars and “hurried back to camp, where we settled down to decipher them.” The inscription turned out to be a date: September 3, 32 B.C., in today’s calendar.

  Stirling already knew that Tres Zapotes was anomalous—it was at least 150 miles west of any previously discovered Maya settlement. The date deepened the puzzle. If, as seemed likely, it recorded when the stela was put on display, this implied that Tres Zapotes had been a going concern in 32 B.C.—centuries before any other known Maya site. The date thus seemed to imply that the Maya had originated well to the west of what was thought of as their traditional homeland, and much earlier than had been thought. Stirling didn’t believe it. Surely the Maya had not sprung up in Tres Zapotes and then moved en masse hundreds of miles to the east. But the alternative explanation—that Tres Zapotes was not a Maya community—seemed equally improbable. The Maya were universally regarded as the oldest advanced society in Mesoamerica. Whoever had carved the stela had some knowledge of writing and mathematics. If they were not Maya, the implication was that someone else had launched the project of civilization in Mesoamerica.