The Columbian Exchange
by Alfred Crosby
Professor Emeritus, University of Texas at Austin

Millions of years ago, continental drift carried the Old World and New Worlds apart, splitting North and South America from Eurasia and Africa. That separation lasted so long that it fostered divergent evolution; for instance, the development of rattlesnakes on one side of the Atlantic and vipers on the other. After 1492, human voyagers in part reversed this tendency. Their artificial re-establishment of connections through the commingling of Old and New World plants, animals, and bacteria, commonly known as the Columbian Exchange, is one of the more spectacular and significant ecological events of the past millennium.

When Europeans first touched the shores of the Americas, Old World crops such as wheat, barley, rice, and turnips had not traveled west across the Atlantic, and New World crops such as maize, white potatoes, sweet potatoes, and manioc had not traveled east to Europe. In the Americas, there were no horses, cattle, sheep, or goats, all animals of Old World origin. Except for the llama, alpaca, dog, a few fowl, and guinea pig, the New World had no equivalents to the domesticated animals associated with the Old World, nor did it have the pathogens associated with the Old World’s dense populations of humans and such associated creatures as chickens, cattle, black rats, and Aedes egypti mosquitoes. Among these germs were those that carried smallpox, measles, chickenpox, influenza, malaria, and yellow fever.

The Columbian exchange of crops affected both the Old World and the New. Amerindian crops that have crossed oceans – for example, maize to China and the white potato to Ireland - have been stimulants to population growth in the Old World. The latter’s crops and livestock have had much the same effect in the Americas – for example, wheat in Kansas and the Pampa, and beef cattle in Texas and Brazil. The full story of the exchange is many volumes long, so for the sake of brevity and clarity let us focus on a specific region, the eastern third of the United States of America.

As might be expected, the Europeans who settled on the east coast of the United States cultivated crops like wheat and apples, which they had brought with them. European weeds, which the colonists did not cultivate, and, in fact, preferred to uproot, also fared well in the New World. John Josselyn, an Englishman and amateur naturalist who visited New England twice in the seventeenth century, left us a list, "Of Such Plants as Have Sprung Up since the English Planted and Kept Cattle in New England," which included couch grass, dandelion, shepherd's purse, groundsel, sow thistle, and chickweeds. One of these, a plantain (Plantago major), was named "Englishman's Foot" by the Amerindians of New England and Virginia who believed that it would grow only where the English "have trodden, and was never known before the English came into this country." Thus, as they intentionally sowed Old World crop seeds, the European settlers were unintentionally contaminating American fields with weed seed. More importantly, they were stripping and burning forests, exposing the native minor flora to direct sunlight, and the hooves and teeth of Old World livestock. The native flora could not tolerate the stress. The imported weeds could, because they had lived with large numbers of grazing animals for thousands of years.

Cattle and horses were brought ashore in the early 1600s and found hospitable climate and terrain in North America. Horses arrived in Virginia as early as 1620 and in Massachusetts in 1629. Many wandered free with little more evidence of their connection to humanity than collars with a hook at the bottom to catch on fences as they tried to leap over them to get at crops. Fences were not for keeping livestock in, but for keeping livestock out.

Native American resistance to the Europeans was ineffective. Indigenous peoples suffered from white brutality, alcoholism, the killing and driving off of game, and the expropriation of farmland, but all these together are insufficient to explain the degree of their defeat. The crucial factor was not people, plants, or animals, but germs. The history of the United States begins with Virginia and Massachusetts, and their histories begin with epidemics of unidentified diseases. At the time of the abortive Virginia colony at Roanoke in the 1580s the nearby Amerindians “began to die quickly. The disease was so strange that they neither knew what it was, nor how to cure it….”¹ When the Pilgrims settled at Plymouth, Massachusetts in 1620, they did so in a village and on a coast nearly cleared of Amerindians by a recent epidemic. Thousands had "died in a great plague not long since; and pity it was and is to see so many goodly fields, and so well seated, without man to dress and manure the same."²

Smallpox was the worst and the most spectacular of the infectious diseases mowing down the Native Americans. The first recorded pandemic of that disease in British North America detonated among the Algonquin of Massachusetts in the early 1630s: William Bradford of Plymouth Plantation wrote that the victims “fell down so generally of this disease as they were in the end not able to help one another, no not to make a fire nor fetch a little water to drink, nor any to bury the dead.”

The missionaries and the traders who ventured into the American interior told the same appalling story about smallpox and the indigenes. In 1738 alone the epidemic destroyed half the Cherokee; in 1759 nearly half the Catawbas; in the first years of the next century two-thirds of the Omahas and perhaps half the entire population between the Missouri River and New Mexico; in 1837-38 nearly every last one of the Mandans and perhaps half the people of the high plains.

European explorers encountered distinctively American illnesses such as Chagas Disease, but these did not have much effect on Old World populations. Venereal syphilis has also been called American, but that accusation is far from proven. Even if we add all the Old World deaths blamed on American diseases together, including those ascribed to syphilis, the total is insignificant compared to Native American losses to smallpox alone.

The export of America’s native animals has not revolutionized Old World agriculture or ecosystems as the introduction of European animals to the New World did. America’s grey squirrels and muskrats and a few others have established themselves east of the Atlantic and west of the Pacific, but that has not made much of a difference. Some of America’s domesticated animals are raised in the Old World, but turkeys have not displaced chickens and geese, and guinea pigs have proved useful in laboratories, but have not usurped rabbits in the butcher shops.

The New World’s great contribution to the Old is in crop plants. Maize, white potatoes, sweet potatoes, various squashes, chiles, and manioc have become essentials in the diets of hundreds of millions of Europeans, Africans, and Asians. Their influence on Old World peoples, like that of wheat and rice on New World peoples, goes far to explain the global population explosion of the past three centuries. The Columbian Exchange has been an indispensable factor in that demographic explosion.

All this had nothing to do with superiority or inferiority of biosystems in any absolute sense. It has to do with environmental contrasts. Amerindians were accustomed to living in one particular kind of environment, Europeans and Africans in another. When the Old World peoples came to America, they brought with them all their plants, animals, and germs, creating a kind of environment to which they were already adapted, and so they increased in number. Amerindians had not adapted to European germs, and so initially their numbers plunged. That decline has reversed in our time as Amerindian populations have adapted to the Old World’s environmental influence, but the demographic triumph of the invaders, which was the most spectacular feature of the Old World’s invasion of the New, still stands.


¹ Quinn, David B., Ed. The Roanoke Voyages, 1584-1590: Documents to Illustrate the English Voyages to North America. London: Hakluyt Society, 1955, 378.

² Winslow, Edward, Morton, Nathaniel, Bradford, William, and Prince, Thomas. New England’s Memorial. Cambridge: Allan and Farnham, 1855, 362.

Decades before Columbus, Zheng He sailed from China with 300 ships and 28,000 men. His fleet got as far as Africa and could have easily reached America, but the Chinese turned back. What happened? By NICHOLAS D. KRISTOF    Photographs by GUEORGUI PINKHASSOV

rom the sea, the tiny East African island of Pate, just off the Kenyan coast, looks much as it must have in the 15th century: an impenetrable shore of endless mangrove trees. As my little boat bounced along the waves in the gray dawn, I could see no antennae or buildings or even gaps where trees had been cut down, no sign of human habitation, nothing but a dense and mysterious jungle.

The boatman drew as close as he could to a narrow black-sand beach, and I splashed ashore. My local Swahili interpreter led the way through the forest, along a winding trail scattered with mangoes, coconuts and occasional seashells deposited by high tides. The tropical sun was firmly overhead when we finally came upon a village of stone houses with thatched roofs, its dirt paths sheltered by palm trees. The village's inhabitants, much lighter-skinned than people on the Kenyan mainland, emerged barefoot to stare at me with the same curiosity with which I was studying them. These were people I had come halfway around the world to see, in the hope of solving an ancient historical puzzle.

"Tell me," I asked the first group I encountered, "where did the people here come from? Long ago, did foreign sailors ever settle here?"

The answer was a series of shrugs. "I've never heard about that," one said. "You'll have to ask the elders."

I tried several old men and women without success. Finally the villagers led me to the patriarch of the village, Bwana Mkuu Al-Bauri, the keeper of oral traditions. He was a frail old man with gray stubble on his cheeks, head and chest. He wore a yellow sarong around his waist; his ribs pressed through the taut skin on his bare torso. Al-Bauri hobbled out of his bed, resting on a cane and the arm of a grandson. He claimed to be 121 years old; a pineapple-size tumor jutted from the left side of his chest.

"I know this from my grandfather, who himself was the keeper of history here," the patriarch told me in an unexpectedly clear voice. "Many, many years ago, there was a ship from China that wrecked on the rocks off the coast near here. The sailors swam ashore near the village of Shanga -- my ancestors were there and saw it themselves. The Chinese were visitors, so we helped those Chinese men and gave them food and shelter, and then they married our women. Although they do not live in this village, I believe their descendants still can be found somewhere else on this island."

I almost felt like hugging Bwana Al-Bauri. For months I had been poking around obscure documents and research reports, trying to track down a legend of an ancient Chinese shipwreck that had led to a settlement on the African coast. My interest arose from a fascination with what to me is a central enigma of the millennium: why did the West triumph over the East?

For most of the last several thousand years, it would have seemed far likelier that Chinese or Indians, not Europeans, would dominate the world by the year 2000, and that America and Australia would be settled by Chinese rather than by the inhabitants of a backward island called Britain. The reversal of fortunes of East and West strikes me as the biggest news story of the millennium, and one of its most unexpected as well.

As a resident of Asia for most of the past 13 years, I've been searching for an explanation. It has always seemed to me that the turning point came in the early 1400's, when Admiral Zheng He sailed from China to conquer the world. Zheng He (pronounced jung huh) was an improbable commander of a great Chinese fleet, in that he was a Muslim from a rebel family and had been seized by the Chinese Army when he was still a boy. Like many other prisoners of the time, he was castrated -- his sexual organs completely hacked off, a process that killed many of those who suffered it. But he was a brilliant and tenacious boy who grew up to be physically imposing. A natural leader, he had the good fortune to be assigned, as a houseboy, to the household of a great prince, Zhu Di.

In time, the prince and Zheng He grew close, and they conspired to overthrow the prince's nephew, the Emperor of China. With Zheng He as one of the prince's military commanders, the revolt succeeded and the prince became China's Yongle Emperor. One of the emperor's first acts (after torturing to death those who had opposed him) was to reward Zheng He with the command of a great fleet that was to sail off and assert China's pre-eminence in the world.

Between 1405 and 1433, Zheng He led seven major expeditions, commanding the largest armada the world would see for the next five centuries. Not until World War I did the West mount anything comparable. Zheng He's fleet included 28,000 sailors on 300 ships, the longest of which were 400 feet. By comparison, Columbus in 1492 had 90 sailors on three ships, the biggest of which was 85 feet long. Zheng He's ships also had advanced design elements that would not be introduced in Europe for another 350 years, including balanced rudders and watertight bulwark compartments.

The sophistication of Zheng He's fleet underscores just how far ahead of the West the East once was. Indeed, except for the period of the Roman Empire, China had been wealthier, more advanced and more cosmopolitan than any place in Europe for several thousand years. Hangzhou, for example, had a population in excess of a million during the time it was China's capital (in the 12th century), and records suggest that as early as the 7th century, the city of Guangzhou had 200,000 foreign residents: Arabs, Persians, Malays, Indians, Africans and Turks. By contrast, the largest city in Europe in 1400 was probably Paris, with a total population of slightly more than 100,000.

A half-century before Columbus, Zheng He had reached East Africa and learned about Europe from Arab traders. The Chinese could easily have continued around the Cape of Good Hope and established direct trade with Europe. But as they saw it, Europe was a backward region, and China had little interest in the wool, beads and wine Europe had to trade. Africa had what China wanted -- ivory, medicines, spices, exotic woods, even specimens of native wildlife.

In Zheng He's time, China and India together accounted for more than half of the world's gross national product, as they have for most of human history. Even as recently as 1820, China accounted for 29 percent of the global economy and India another 16 percent, according to the calculations of Angus Maddison, a leading British economic historian.

Asia's retreat into relative isolation after the expeditions of Zheng He amounted to a catastrophic missed opportunity, one that laid the groundwork for the rise of Europe and, eventually, America. Westerners often attribute their economic advantage today to the intelligence, democratic habits or hard work of their forebears, but a more important reason may well have been the folly of 15th-century Chinese rulers. That is why I came to be fascinated with Zheng He and set out earlier this year to retrace his journeys. I wanted to see what legacy, if any, remained of his achievement, and to figure out why his travels did not remake the world in the way that Columbus's did.

Zheng He lived in Nanjing, the old capital, where I arrived one day in February. Nanjing is a grimy metropolis on the Yangtze River in the heart of China. It has been five centuries since Zheng He's death, and his marks on the city have grown faint. The shipyards that built his fleet are still busy, and the courtyard of what had been his splendid 72-room mansion is now the Zheng He Memorial Park, where children roller-skate and old couples totter around for exercise. But though the park has a small Zheng He museum, it was closed -- for renovation, a caretaker told me, though he knew of no plans to reopen it.

I'd heard that Zheng He's tomb is on a hillside outside the city, and I set out to find it. It wasn't long before the road petered out, from asphalt to gravel to dirt to nothing. No tomb was in sight, so I approached an old man weeding a vegetable garden behind his house. Tang Yiming, 72, was still lithe and strong. His hair was gray and ragged where he had cut it himself, disastrously, in front of a mirror. Evidently lonely, he was delighted to talk, and offered to show me the path to the tomb. As we walked, I mentioned that I had read that there used to be an old Ming Dynasty tablet on Zheng He's grave.

"Oh, yeah, the old tablet," he said nonchalantly. "When I was a boy, there was a Ming Dynasty tablet here. When it disappeared, the Government offered a huge reward to anyone who would return it -- a reward big enough to build a new house. Seemed like a lot of money. But the problem was that we couldn't give it back. People around here are poor. We'd smashed it up to use as building materials."

A second mystery concerned what, if anything, is actually buried in Zheng He's tomb, since he is believed to have died on his last voyage and been buried at sea. So I said in passing that I'd heard tell the tomb is empty, and let my voice trail off.

"Oh, there's nothing in there," Tang said, a bit sadly. "No bones, nothing. That's for sure."

"How do you know?"

"In 1962, people dug up the grave, looking for anything to sell. We dug up the ground to one and a half times the height of a man. But there was absolutely nothing in there. It's empty."

The absence of impressive monuments to Zheng He in China today should probably come as no surprise, since his achievement was ultimately renounced. Curiously, it is not in China but in Indonesia where his memory has been most actively kept alive. Zheng He's expeditions led directly to the wave of Chinese immigration to Southeast Asia, and in some countries he is regarded today as a deity. In the Indonesia city of Semarang, for example, there is a large temple honoring Zheng He, located near a cave where he once nursed a sick friend. Indonesians still pray to Zheng He for a cure or good luck.

Not so in his native land. Zheng He was viewed with deep suspicion by China's traditional elite, the Confucian scholars, who made sure to destroy the archives of his journey. Even so, it is possible to learn something about his story from Chinese sources -- from imperial archives and even the memoirs of crewmen. The historical record makes clear, for example, that it was not some sudden impulse of extroversion that led to Zheng He's achievement. It grew, rather, out of a long sailing tradition. Chinese accounts suggest that in the fifth century, a Chinese monk sailed to a mysterious "far east country" that sounds very much like Mayan Mexico, and Mayan art at that time suddenly began to include Buddhist symbols. By the 13th century, Chinese ships regularly traveled to India and occasionally to East Africa.

Zheng He's armada was far grander, of course, than anything that came before. His grandest vessels were the "treasure ships," 400 feet long and 160 feet wide, with nine masts raising red silk sails to the wind, as well as multiple decks and luxury cabins with balconies. His armada included supply ships to carry horses, troop transports, warships, patrol boats and as many as 20 tankers to carry fresh water. The full contingent of 28,000 crew members included interpreters for Arabic and other languages, astrologers to forecast the weather, astronomers to study the stars, pharmacologists to collect medicinal plants, ship-repair specialists, doctors and even two protocol officers to help organize official receptions.

In the aftermath of such an incredible undertaking, you somehow expect to find a deeper mark on Chinese history, a greater legacy. But perhaps the faintness of Zheng He's trace in contemporary China is itself a lesson. In the end, an explorer makes history but does not necessarily change it, for his impact depends less on the trail he blazes than on the willingness of others to follow. The daring of a great expedition ultimately is hostage to the national will of those who remain behind.

In February I traveled To calicut, a port town in southwestern India that was (and still is) the pepper capital of the world. The evening I arrived, I went down to the beach in the center of town to look at the coastline where Zheng He once had berthed his ships. In the 14th and 15th centuries, Calicut was one of the world's great ports, known to the Chinese as "the great country of the Western ocean." In the early 15th century, the sight of Zheng He's fleet riding anchor in Calicut harbor symbolized the strength of the world's two greatest powers, China and India.

On this sultry evening, the beach, framed by long piers jutting out to sea, was crowded with young lovers and ice-cream vendors. Those piers are all that remain of the port of Calicut, and you can see at a glance that they are no longer usable. The following day I visited the port offices, musty with handwritten ledgers of ship visits dating back nearly a century. The administrator of the port, Captain E. G. Mohanan, explained matter-of-factly what had happened. "The piers got old and no proper maintenance was ever carried out," he said, as a ceiling fan whirred tiredly overhead. "By the time we thought of it, it was not economical to fix it up." So in 1989, trade was halted, and one of the great ports of the world became no port at all.

The disappearance of a great Chinese fleet from a great Indian port symbolized one of history's biggest lost opportunities -- Asia's failure to dominate the second half of this millennium. So how did this happen?

While Zheng He was crossing the Indian Ocean, the Confucian scholar-officials who dominated the upper echelons of the Chinese Government were at political war with the eunuchs, a group they regarded as corrupt and immoral. The eunuchs' role at court involved looking after the concubines, but they also served as palace administrators, often doling out contracts in exchange for kickbacks. Partly as a result of their legendary greed, they promoted commerce. Unlike the scholars -- who owed their position to their mastery of 2,000-year-old texts -- the eunuchs, lacking any such roots in a classical past, were sometimes outward-looking and progressive. Indeed, one can argue that it was the virtuous, incorruptible scholars who in the mid-15th century set China on its disastrous course.

After the Yongle Emperor died in 1424, China endured a series of brutal power struggles; a successor emperor died under suspicious circumstances and ultimately the scholars emerged triumphant. They ended the voyages of Zheng He's successors, halted construction of new ships and imposed curbs on private shipping. To prevent any backsliding, they destroyed Zheng He's sailing records and, with the backing of the new emperor, set about dismantling China's navy.

By 1500 the Government had made it a capital offense to build a boat with more than two masts, and in 1525 the Government ordered the destruction of all oceangoing ships. The greatest navy in history, which a century earlier had 3,500 ships (by comparison, the United States Navy today has 324), had been extinguished, and China set a course for itself that would lead to poverty, defeat and decline.

Still, it was not the outcome of a single power struggle in the 1440's that cost China its worldly influence. Historians offer a host of reasons for why Asia eventually lost its way economically and was late to industrialize; two and a half reasons seem most convincing.

The first is that Asia was simply not greedy enough. The dominant social ethos in ancient China was Confucianism and in India it was caste, with the result that the elites in both nations looked down their noses at business. Ancient China cared about many things -- prestige, honor, culture, arts, education, ancestors, religion, filial piety -- but making money came far down the list. Confucius had specifically declared that it was wrong for a man to make a distant voyage while his parents were alive, and he had condemned profit as the concern of "a little man." As it was, Zheng He's ships were built on such a grand scale and carried such lavish gifts to foreign leaders that the voyages were not the huge money spinners they could have been.

In contrast to Asia, Europe was consumed with greed. Portugal led the age of discovery in the 15th century largely because it wanted spices, a precious commodity; it was the hope of profits that drove its ships steadily farther down the African coast and eventually around the Horn to Asia. The profits of this trade could be vast: Magellan's crew once sold a cargo of 26 tons of cloves for 10,000 times the cost.

A second reason for Asia's economic stagnation is more difficult to articulate but has to do with what might be called a culture of complacency. China and India shared a tendency to look inward, a devotion to past ideals and methods, a respect for authority and a suspicion of new ideas. David S. Landes, a Harvard economist, has written of ancient China's "intellectual xenophobia"; the former Indian Prime Minister Jawaharlal Nehru referred to the "petrification of classes" and the "static nature" of Indian society. These are all different ways of describing the same economic and intellectual complacency.

Chinese elites regarded their country as the "Middle Kingdom" and believed they had nothing to learn from barbarians abroad. India exhibited much of the same self-satisfaction. "Indians didn't go to Portugal not because they couldn't but because they didn't want to," mused M. P. Sridharan, a historian, as we sat talking on the porch of his home in Calicut.

The 15th-century Portuguese were the opposite. Because of its coastline and fishing industry, Portugal always looked to the sea, yet rivalries with Spain and other countries shut it out of the Mediterranean trade. So the only way for Portugal to get at the wealth of the East was by conquering the oceans.

The half reason is simply that China was a single nation while Europe was many. When the Confucian scholars reasserted control in Beijing and banned shipping, their policy mistake condemned all of China. In contrast, European countries committed economic suicide selectively. So when Portugal slipped into a quasi-Chinese mind-set in the 16th century, slaughtering Jews and burning heretics and driving astronomers and scientists abroad, Holland and England were free to take up the slack.

When I first began researching Zheng He, I never thought I'd be traveling all the way to Africa to look for traces of his voyages. Then I came across a few intriguing references to the possibility of an ancient Chinese shipwreck that might have left some Chinese stranded on the island of Pate (pronounced pah-tay). One was a skeptical reference in a scholarly journal, another was a casual conversation with a Kenyan I met a few years ago and the third was the epilogue of Louise Levathes's wonderful 1994 book about China's maritime adventures, "When China Ruled the Seas." Levathes had traveled to Kenya and found people who believed they were descended from survivors of a Chinese shipwreck. So, on a whim and an expense account, I flew to Lamu, an island off northern Kenya, and hired a boat and an interpreter to go to Pate and see for myself.

Pate is off in its own world, without electricity or roads or vehicles. Mostly jungle, it has been shielded from the 20th century largely because it is accessible from the Kenyan mainland only by taking a boat through a narrow tidal channel that is passable only at high tide. Initially I was disappointed by what I found there. In the first villages I visited, I saw people who were light-skinned and had hair that was not tightly curled, but they could have been part Arab or European rather than part Chinese. The remote villages of Chundwa and Faza were more promising, for there I found people whose eyes, hair and complexion hinted at Asian ancestry, though their background was ambiguous.

And then on a still and sweltering afternoon I strolled through the coconut palms into the village of Siyu, where I met a fisherman in his 40's named Abdullah Mohammed Badui. I stopped and stared at the man in astonishment, for he had light skin and narrow eyes. Fortunately, he was as rude as I was, and we stared at each other in mutual surprise before venturing a word. Eventually I asked him about his background and appearance.

"I am in the Famao clan," he said. "There are 50 or 100 of us Famao left here. Legend has it that we are descended from Chinese and others.

"A Chinese ship was coming along and it hit rocks and wrecked," Badui continued. "The sailors swam ashore to the village that we now call Shanga, and they married the local women, and that is why we Famao look so different."

Another Famao, with the same light complexion and vaguely Asian features, approached to listen. His name was Athman Mohammed Mzee, and he, too, told of hearing of the Chinese shipwreck from the elders. He volunteered an intriguing detail: the Africans had given giraffes to the Chinese.

Salim Bonaheri, a 55-year-old Famao man I met the next day, proudly declared, "My ancestors were Chinese or Vietnamese or something like that." I asked how they had got to Pate.

"I don't know," Bonaheri said with a shrug.

Most of my conversations were like that, intriguing but frustrating dead ends. I was surrounded by people whose appearance seemed tantalizingly Asian, but who had only the vaguest notions of why that might be. I kept at it, though, and eventually found people like Khalifa Mohammed Omar, a 55-year-old Famao fisherman who looked somewhat Chinese and who also clearly remembered the stories passed down by his grandfather. From him and others, a tale emerged.

Countless generations ago, they said, Chinese sailors traded with local African kings. The local kings gave them giraffes to take back to China. One of the Chinese ships struck rocks off the eastern coast of Pate, and the sailors swam ashore, carrying with them porcelain and other goods from the ship. In time they married local women, converted to Islam and named the village Shanga, after Shanghai. Later, fighting erupted among Pate's clans, Shanga was destroyed and the Famao fled, some to the mainland, others to the village of Siyu.

Every time I heard the story about the giraffes my pulse began to race. Chinese records indicate that Zheng He had brought the first giraffes to China, a fact that is not widely known. The giraffe caused an enormous stir in China because it was believed to be the mythical qilin, or Chinese unicorn. It is difficult to imagine how African villagers on an island as remote as Pate would know about the giraffes unless the tale had been handed down to them by the Chinese sailors.

Chinese ceramics are found in many places along the east African coast, and their presence on Pate could be the result of purchases from Arab traders. But the porcelain on Pate was overwhelmingly concentrated among the Famao clan, which could mean that it had been inherited rather than purchased. I also visited some ancient Famao graves that looked less like traditional Kenyan graves than what the Chinese call "turtle-shell graves," with rounded tops.

Researchers have turned up other equally tantalizing clues. Craftsmen on Pate and the other islands of Lamu practice a kind of basket-weaving that is common in southern China but unknown on the Kenyan mainland. On Pate, drums are more often played in the Chinese than the African style, and the local dialect has a few words that may be Chinese in origin. More startling, in 1569 a Portuguese priest named Monclaro wrote that Pate had a flourishing silk-making industry -- Pate, and no other place in the region. Elders in several villages on Pate confirmed to me that their island had produced silk until about half a century ago.

When I asked my boatman, Bakari Muhaji Ali, if he thought it was possible that a ship could have wrecked off the coast near Shanga, he laughed. "There are undersea rocks all over there," he said. "If you don't know exactly where you're going, you'll wreck your ship for sure."

If indeed there was a Chinese shipwreck off Pate, there is reason to think it happened in Zheng He's time. For if the shipwreck had predated him, surviving sailors would not have passed down stories of the giraffes. And if the wreck didn't occur until after Zheng He, its survivors could not have settled in Shanga, since British archeological digs indicate that the village was sacked, burned and abandoned in about 1440 -- very soon after Zheng He's last voyage.

Still, there is no hard proof for the shipwreck theory, and there are plenty of holes in it. No ancient Chinese characters have been found on tombs in Pate, no nautical instruments have ever turned up on the island and there are no Chinese accounts of an African shipwreck. This last lacuna might be explained by the destruction of the fleet's records. Yet if one of Zheng He's ships did founder on the rocks off Pate, then why didn't some other ships in the fleet come to the sailors' rescue?

As I made my way back through the jungle for the return trip, I pondered the significance of what I'd seen on Pate. In the faces of the Famao, in those bits of pottery and tantalizing hints of Chinese culture, I felt as though I'd glimpsed the shadowy outlines of one of the greatest might-have-beens of the millennium now ending. I thought about the Columbian Exchange, the swap of animals, plants, genes, germs, weapons and peoples that utterly remade both the New World and the Old, and I couldn't help wondering about another exchange -- Zheng He's -- that never took place, yet could have.

If ancient China had been greedier and more outward-looking, if other traders had followed in Zheng He's wake and then continued on, Asia might well have dominated Africa and even Europe. Chinese might have settled in not only Malaysia and Singapore, but also in East Africa, the Pacific Islands, even in America. Perhaps the Famao show us what the mestizos of such a world might have looked liked, the children of a hybrid culture that was never born. What I'd glimpsed in Pate was the high-water mark of an Asian push that simply stopped -- not for want of ships or know-how, but strictly for want of national will.

All this might seem fanciful, and yet in Zheng He's time the prospect of a New World settled by the Spanish or English would have seemed infinitely more remote than a New World made by the Chinese. How different would history have been had Zheng He continued on to America? The mind rebels; the ramifications are almost too overwhelming to contemplate. So consider just one: this magazine would have been published in Chinese.

Copyright 1999 The New York Times Company