INTERLUDE
Millions of years ago, the Old and New Worlds belonged to one giant landmass, Pangaea, meaning “All Land.” The geologic paradigm known as continental drift, first proposed by the Flemish cartographer Abraham Ortelius in 1596, slowly drove the continents thousands of miles apart.
As recently (in geologic terms) as 125 million years ago, when dinosaurs still inhabited the earth, large portions of North America were joined to the Eurasian landmass. A giant, amorphous ocean—and its currents—freely circulated the globe. Not until 30 million years ago did the oceans begin to assume their present configuration, but even then, the Atlantic Ocean reached from the poles to the tropics. A new phenomenon, the Gulf Stream, a remnant of the ancient transglobal current, distributed and redistributed life across its length. As Pangaea slowly fragmented, the resulting continents developed divergent evolution—that is, life-forms on each continent evolved separately, sometimes on parallel tracks, and in other cases quite differently.
It seemed that matters would go on this way indefinitely, despite fleeting instances of natural transoceanic contact. But in 1492 the voyages of Columbus and his successors suddenly and permanently altered this age-old pattern, bursting the evolutionary bubbles of previously independent continents. It is challenging to consider that one fleet, led by the vision and determination of a single individual, set in motion the events that brought about this lasting global change, but that is what occurred.
Not that Columbus realized it at the time. Arriving in the Americas, he was dumbfounded by the profusion of unfamiliar flora and fauna he faced. He was at times deeply frustrated by his inability to put a name to plants and animals he saw. The few learned men aboard his ships, such as his physician, Dr. Chanca, were similarly baffled.
The world was a very different place in 1492. When Columbus was journeying across the Atlantic, tomatoes, and tomato sauce, were unknown in Italy, or anywhere in Europe. The same situation applied to chocolate, widespread in the Americas for three thousand years before Columbus, but unfamiliar to European palates. Tobacco presented a similar case: deeply woven into Indian life and ritual, but unknown to Europeans. When Columbus and his men encountered these items, they did not know what to make of them. Yet, as a result of their importing these products to Europe, and transplanting flora and fauna they had brought with them in their ships, some as large as horses, others as small as microorganisms, the Old World and the New became interconnected in ways that no one, least of all Columbus, anticipated.
Nothing would ever be the same. Columbus could not have guessed that the most lasting and irreversible effects of his voyages would transcend his quest for empire and trade; instead, he inadvertently transformed the global environment. More than Christianity, or slavery, or gold, or any of the other forces with which Columbus and Spain grappled, this two-way transmission between the Old World and the New World brought about changes larger than they could have imagined. The transformation was wide-ranging, cataclysmic, and enduring. And it would take years, decades, centuries for the effects of this two-way transmission to unfold.
This slow-moving spectacle is known as the Columbian Exchange, first identified by Alfred Crosby, a professor at the University of Texas in Austin, in 1972. Within a couple of decades, Crosby’s insights gave rise to a new way of considering the Columbian legacy. “When Europeans first touched the shores of the Americas,” he wrote, “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.” These vast differences extended to animal life as well. “In the Americas, there were no horses, cattle, sheep or goats.” They were all “animals of Old World origin.” In fact, with few exceptions, the New World had no domesticated animals, no chickens, and no cattle until the coming of Columbus. And when they did arrive, their presence changed the hunting, eating, and ultimately the migratory habits and tribal structures of the Indians who made use of them for food, labor, and companionship.
Their effects percolated through the culture in ways that the Spaniards could not have imagined. Take the horses that Columbus brought along with him, for instance. At first, they terrified the Indians, who had never seen beasts such as these. In time, the horses spread north, transforming Indian life. “The horse gave the Indian the speed and stamina needed to take advantage of the opportunity to harvest the immense quantities of food represented by the buffalo herds of North America and the herds of wild cattle that propagated so rapidly in the grasslands of both Americas,” Crosby observed. There were still more unexpected consequences. “The Indians stopped farming; the work was hard, boring, and unrewarding, compared with nomadic life.” So the Indians mounted their steeds and roamed the pampas, killing more animals than ever before as they went, more animals than they needed for themselves and their families. The Indian on horseback could increase and multiply. Greater numbers of Indians led to a growing division between rich and poor, to social stratification, and to slavery. As Crosby put it, “the egalitarianism of poverty began to disappear.”
So the animals brought by Europeans were not an unmixed blessing. Along with them—and with the associated black rats and sinister Aedes aegypti mosquitoes—came deadly disease: smallpox, measles, chicken pox, influenza, yellow fever, and dengue fever. These pathogens infiltrated the New World, leaving destruction and suffering in their wake. The human animal also brought its pathogens, including syphilis.
Syphilis is the most commonly cited example of disease transmission between the Old World and the New for which Columbus’s voyages are held responsible, but there is little consensus about which way the venereal diseases traveled. Did the Indians infect the Spaniards, or was it the other way around? Accounts of syphilis arising spontaneously on both continents further complicated the question of how the disease spread. Clearly some of Columbus’s crew suffered from syphilislike symptoms, as Dr. Chanca noted. But did they acquire the disease by mingling with Indian women, or did they bring the disease with them and transmit it to their unsuspecting victims? Or were different strains passed back and forth? This notorious aspect of the Columbian Exchange remains unanswered.
On a more positive side of the ledger, the Columbian Exchange introduced staples such as white potatoes, sweet potatoes, maize, and cassava to Europe, and brought wheat, turnips, barley, apples, and rice from Europe to the Americas. In the two-way transmission of the Columbian Exchange, a fragrant and colorful stream of lilacs and daisies and daffodils, along with lemons, oranges, lettuce, cabbage, pears, peaches, bananas, and coffee traveled from the Old World to the New. Meanwhile, pumpkins, squash, lima beans, and peppers traveled from the New World to the Old, as did peanuts, chocolate, and sweet potatoes. Honeybees arrived in the Americas, turkeys in the Old.
These crops were associated with population growth and economic growth. That was fine as far as it went, and relatively benign. But the Europeans also brought with them alcohol and alcoholism, another scourge that decimated heretofore innocent local populations. The devastating effects of European agriculture and pathogens on American Indians and their land did not mean the New World’s ecosystem and its peoples were inferior; it resulted from the novelty of the assault. In time, plants, animals, and people adapted to the invaders, long after the devastation wrought by the initial contact.
Once started, the Columbian Exchange never ceased, and it continues at an ever-accelerating pace. Crosby called the phenomenon a “wild oscillation of nature” that occurs when an isolated region emerges into the larger environment. “Possibly it will never be repeated in as spectacular fashion as in the Americas in the first post-Columbian century, not unless there is, one day, an exchange of life forms between planets.”
For better or worse, or rather, for better and worse, this is Columbus’s enduring, relentless, inescapable, all-encompassing legacy.