(Illustration Credit 4.4)

  When Cortés and his Indian allies finally attacked, the Mexica resisted so fiercely despite their weakness that the siege has often been described as the costliest battle in history—casualty estimates range up to 100,000. Absent smallpox, it seems likely that Cortés would have lost. In the event, he was able to take the city only by systematically destroying it. The Alliance capitulated on August 21, 1521. It was the end of an imperial tradition that dated back to Teotihuacan a millennium before.

  Cortés was directly responsible for much of the carnage in Tenochtitlan, but the war was only a small part of a larger catastrophe for which blame is harder to assign. When Cortés landed, according to the Berkeley researchers Cook and Borah, 25.2 million people lived in central Mexico, an area of about 200,000 square miles. After Cortés, the population of the entire region collapsed. By 1620–25, it was 730,000, “approximately 3 percent of its size at the time that he first landed.” Cook and Borah calculated that the area did not recover its fifteenth-century population until the late 1960s.

  From Bartolomé de Las Casas on, Europeans have known that their arrival brought about a catastrophe for Native Americans. “We, Christians, have destroyed so many kingdoms,” reflected Pedro Cieza de León, the traveler in postconquest Peru. “For wherever the Spaniards have passed, conquering and discovering, it is as though a fire had gone, destroying everything in its path.” And since Las Casas historians, clerics, and political activists have debated whether Europeans and their descendants in the Americas are morally culpable for the enormous Indian losses. Indeed, some writers have employed the loaded term “holocaust” to describe the contact and its aftermath. Following in its train, inevitably, has come an even more potent label: genocide.

  Europe’s defenders argue that the mass deaths cannot be described as genocide. The epidemics often were not even known to Europeans, still less deliberately caused by them. For that reason, they fall into a different moral class than the Jewish Holocaust, which was a state policy of mass murder. “Very probably the greatest demographic disaster in history, the depopulation of the New World, for all its terror and death, was largely an unintended tragedy,” wrote Steven Katz in his monumental Holocaust in Historical Context. The wave of Indian deaths, in his view, was “a tragedy that occurred despite the sincere and indisputable desire of the Europeans to keep the Indian population alive.”

  POPULATION LOSSES IN CENTRAL MEXICO

  Berkeley researchers Cook and Borah spent decades reconstructing the population of the former Triple Alliance realm in the wake of the Spanish conquest. By combining colonial-era data from many sources, the two men estimated that the number of people in the region fell from 25.2 million in 1518, just before Cortés arrived, to about 700,000 in 1623—a 97 percent drop in little more than a century. (Each marked date is one for which they presented a population estimate.) Using parish records, Mexican demographer Elsa Malvido calculated the sequence of epidemics in the region, portions of which are shown here. Dates are approximate, because epidemics would last several years. The identification of some diseases is uncertain as well; for example, sixteenth-century Spaniards lumped together what today are seen as distinct maladies under the rubric “plague.” In addition, native populations were repeatedly struck by “cocoliztli,” a disease the Spanish did not know but that scientists have suggested might be a rat-borne hantavirus—spread, in part, by the postconquest collapse of Indian sanitation measures. Both reconstructions are tentative, but the combined picture of catastrophic depopulation has convinced most researchers in the field.

  Katz overstates his case. True, the conquistadors did not want the Indians to die off en masse. But that desire did not stem from humanitarian motives. Instead, the Spanish wanted native peoples to use as a source of forced labor. In fact, the Indian deaths were such a severe financial blow to the colonies that they led, according to Borah, to an “economic depression” that lasted “more than a century.” To resupply themselves with labor, the Spaniards began importing slaves from Africa.

  Later on, some of the newcomers indeed campaigned in favor of eradicating natives. The poet-physician Oliver Wendell Holmes Sr., for instance, regarded the Indian as but “a sketch in red crayon of a rudimental manhood.” To the “problem of his relation to the white race,” Holmes said, there was one solution: “extermination.” Following such impulses, a few Spanish—and a few French, Portuguese, and British—deliberately spread disease. Many more treated Indians cruelly, murderously so, killing countless thousands. But the pain and death caused from the deliberate epidemics, lethal cruelty, and egregious racism pale in comparison to those caused by the great waves of disease, a means of subjugation that the Europeans could not control and in many cases did not know they had. How can they be morally culpable for it?

  Not so fast, say the activists. Europeans may not have known about microbes, but they thoroughly understood infectious disease. Almost 150 years before Columbus set sail, a Tartar army besieged the Genoese city of Kaffa. Then the Black Death visited. To the defenders’ joy, their attackers began dying off. But triumph turned to terror when the Tartar khan catapulted the dead bodies of his men over the city walls, deliberately creating an epidemic inside. The Genoese fled Kaffa, leaving it open to the Tartars. But they did not run away fast enough; their ships spread the disease to every port they visited.

  Coming from places that had suffered many such experiences, Europeans fully grasped the potential consequences of smallpox. “And what was their collective response to this understanding?” asked Ward Churchill, a longtime pro-Indian activist.

  Did they recoil in horror and say, “Wait a minute, we’ve got to halt the process, or at least slow it down until we can get a handle on how to prevent these effects”? Nope. Their response pretty much across-the-board was to accelerate their rate of arrival, and to spread out as much as was humanly possible.

  But this, too, overstates the case. Neither European nor Indian had a secular understanding of disease. “Sickness was the physical manifestation of the will of God,” Robert Crease, a philosopher of science at the State University of New York at Stony Brook, told me. “You could pass it on to someone, but doing that was like passing on evil, or bad luck, or a bad spirit—the transmission also reflected God’s will.” The conquistadors knew the potential impact of disease, but its actual impact, which they could not control, was in the hands of God.

  The Mexica agreed. In all the indigenous accounts of the conquest and its aftermath, the anthropologist J. Jorge Klor de Alva observed, the Mexica lament their losses, but, “the Spaniards are rarely judged in moral terms, and Cortés is only sporadically considered a villain. It seems to be commonly understood”—at least by this bleakly philosophical, imperially minded group—“that the Spaniards did what any other group would have done or would have been expected to do if the opportunity had existed.”

  Famously, the conquistador Bernal Díaz de Castillo ticked off the reasons he and others joined Cortés: “to serve God and His Majesty [the king of Spain], to give light to those who were in darkness, and to grow rich, as all men desire to do.” In Díaz’s list, spiritual and material motivations were equally important. Cortés was constantly preoccupied by the search for gold, but he also had to be restrained by the priests accompanying him from promulgating the Gospel in circumstances sure to anger native leaders. After the destruction of Tenochtitlan, the Spanish court and intellectual elite were convulsed with argument for a century about whether the conversions were worth the suffering inflicted. Many believed that even if Indians died soon after conversion, good could still occur. “Christianity is not about getting healthy, it’s about getting saved,” Crease said, summarizing. Today few Christians would endorse this argument, but that doesn’t make it any easier to assign the correct degree of blame to their ancestors.

  In an editorial about Black’s analysis of Indian HLA profiles, Jean-Claude Salomon, a medical researcher at France’s Centre National de la
Recherche Scientifique, asked if the likely inevitability of native deaths could “reduce the historical guilt of Europeans.” In a sense it does, Salomon wrote. But it did not let the invaders off the hook—they caused huge numbers of deaths, and knew that they had done it. “Those who carried the microbes across the Atlantic were responsible, but not guilty,” Salomon concluded. Guilt is not readily passed down the generations, but responsibility can be. A first step toward satisfying that responsibility for Europeans and their descendants in North and South America would be to treat indigenous people today with respect—something that, alas, cannot yet be taken for granted. Recognizing and obeying past treaties wouldn’t be a bad idea, either.

  ISN’T THIS ALL JUST REVISIONISM?

  Yes, of course—except that it’s more like re-revisionism. The first European adventurers in the Western Hemisphere did not make careful population counts, but they repeatedly described indigenous America as a crowded, jostling place—“a beehive of people,” as Las Casas put it in 1542. To Las Casas, the Americas seemed so thick with people “that it looked as if God has placed all of or the greater part of the entire human race in these countries.”

  So far as is known, Las Casas never tried to enumerate the original native population. But he did try to calculate how many died from Spanish disease and brutality. In Las Casas’s “sure, truthful estimate,” his countrymen in the first five decades after Columbus wiped out “more than twelve million souls, men and women and children; and in truth I believe, without trying to deceive myself, that it was more than fifteen million.” Twenty years later, he raised his estimate of Indian deaths—and hence of the initial population—to forty million.

  Las Casas’s successors usually shared his ideas—the eighteenth-century Jesuit Francisco Javier Clavijero, for example, asserted that the pre-Columbian population of Mexico alone was thirty million. But gradually a note of doubt crept in. To most historians, the colonial accounts came to seem exaggerated, though exactly why was not often explained. (“Sixteenth-century Europeans,” Cook and Borah dryly remarked, “did indeed know how to count.”) Especially in North America, historians’ guesses at native numbers kept slipping down. By the 1920s they had dwindled to forty or fifty million in the entire hemisphere. Twenty years after that, the estimates had declined by another factor of five.

  Today the picture has reversed. The High Counters seem to be winning the argument, at least for now. No definitive data exist, but the majority of the extant evidentiary scraps indicate it. “Most of the arrows point in that direction,” Denevan said to me. Zambardino, the computer scientist who decried the margin of error in these estimates, noted that even an extremely conservative extrapolation of known figures would still project a precontact population in central Mexico alone of five to ten million, “a very high population, not only in terms of the sixteenth century, but indeed on any terms.” Even Henige, of Numbers from Nowhere, is no Low Counter. In Numbers from Nowhere, he argues that “perhaps 40 million throughout the Western Hemisphere” is a “not unreasonable” figure—putting him at the low end of the High Counters, but a High Counter nonetheless. Indeed, it is the same figure provided by Las Casas, patron saint of High Counters, foremost among the old Spanish sources whose estimates Henige spends many pages discounting.

  To Fenn, the smallpox historian, the squabble over the number of deaths and the degree of blame obscures something more important. In the long run, Fenn says, the consequential finding of the new scholarship is not that many people died but that many people lived. The Americas were filled with an enthusiastically diverse assortment of peoples who had knocked about the continents for millennia. “We are talking about enormous numbers of people,” she told me. “You have to wonder, Who were all these people? And what were they doing?”

  *Just one major disease, syphilis, is believed to have spread the other way, from the Americas to Europe, though this has long been controversial. See Appendix C, “The Syphilis Exception.”

  *Because the point is persistently misunderstood, it bears repeating that Indians’ relative genetic homogeneity does not imply genetic inferiority. Even a champion of Indians like historian Francis Jennings got this wrong: “The Europeans’ capacity to resist certain diseases,” he wrote in his polemical Invasion of America, “made them superior, in the pure Darwinian sense, to the Indians.” No: Spaniards simply represented a wider genetic array. Asserting their superiority is like saying that the motley mob at a football game is somehow intrinsically superior to the closely related attendees of a family reunion.

  *In 2004 two U.S. anthropologists and a Venezuelan medical researcher proposed that Native American susceptibility to infectious disease might have a second cause: helper-T cells, which like HLAs help the immune system recognize foreign objects. To simplify considerably, helper-T cells occur in two main types, one that targets microorganisms and one that targets parasites. The body cannot sustain large numbers of both, and hence adult immune systems tend to be skewed toward one or the other, usually depending on whether as children they were more often exposed to microorganisms or parasites. Indians have historically been burdened by flukes, tapeworms, and nematodes, so they have long had majorities of parasite-fighting helper-T cells. Europeans, who grew up in germ-filled environments, usually lean the other way. As a result, the three researchers suggested, adult Indians were—and possibly still are—more vulnerable to infectious diseases than adult Europeans. Conversely, Europeans would be comparatively more vulnerable to parasites. If further research supports this hypothesis, preventing childhood parasite infections might allow Indian immune systems to orientate themselves toward bacteria and viruses, possibly reducing future deaths.

  *Historians increasingly shy away from the term “Aztec,” because the nineteenth-century naturalist Alexander von Humboldt coined it in a misapprehension. Humboldt’s “Aztecs” were actually the people of three nations, the members of the Triple Alliance.

  PART TWO

  Very Old Bones

  5

  Pleistocene Wars

  POSSIBLY A VERY ODD HAPLOGROUP

  The last time I spoke with Sérgio D. J. Pena, he was hunting for ancient Indians in modern blood. The blood was sealed into thin, rodlike vials in Pena’s laboratory at the Federal University of Minas Gerais, in Belo Horizonte, Brazil’s third-largest city. To anyone who has seen a molecular biology lab on the television news, the racks of refrigerating tanks, whirling DNA extractors, and gene-sequencing machines in Pena’s lab would look familiar. But what Pena was doing with them would not. One way to describe Pena’s goal would be to say that he was trying to bring back a people who vanished thousands of years ago. Another would be to say that he was wrestling with a scientific puzzle that had resisted resolution since 1840.

  In that year Peter Wilhelm Lund, a Danish botanist, found thirty skeletons in caves twenty miles north of Belo Horizonte. The caves were named Lagoa Santa, after a nearby village. Inside them were a jumble of remains from people and big, extinct beasts. If the human and animal bones were from the same time period, as their proximity suggested, the implication was that people had been living in the Americas many thousands of years ago, much longer than most scientists then believed. Who were these ancient hunters? Regarding Europe as the world’s intellectual capital, the intrigued Lund sent most of the skeletons to a museum in his native Copenhagen. He was certain that researchers there would quickly study and identify them. Instead the bones remained in boxes, rarely disturbed, for more than a century.

  Scientists finally examined the Lagoa Santa skeletons in the 1960s. Laboratory tests showed that the bones could be fifteen thousand years old—possibly the oldest human remains in the Western Hemisphere. Lund had noted the skulls’ heavy brows, which are rare in Native Americans. The new measurements confirmed that oddity and suggested that these people were in many ways physically quite distinct from modern Indians, which indicated, at least to some Brazilian archaeologists, that the Lagoa Santa people could not have been the ance
stors of today’s native populations. Instead the earliest inhabitants of the Americas must have been some other kind of people.

  North American researchers tended to scoff at the notion that some mysterious non-Indians had lived fifteen thousand years ago in the heart of Brazil, but South Americans, Pena among them, were less dismissive. Pena had studied and worked for twelve years overseas, mainly in Canada and the United States. He returned in 1982 to Belo Horizonte, a surging, industrial city in the nation’s east-central highlands. In Brazilian terms, it was like abandoning a glamorous expatriate life in Paris to come back to Chicago. Pena had become interested while abroad in using genetics as a historical tool—studying family trees and migrations by examining DNA. At Belo Horizonte, he joined the university faculty and founded, on the side, Brazil’s first DNA-fingerprinting company, providing paternity tests for families and forensic studies for the police. He taught, researched, published in prestigious U.S. and European journals, and ran his company. In time he became intrigued by the Lagoa Santa skeletons.

  The most straightforward way to discover whether the Lagoa Santa people were related to modern Indians, Pena decided, would be to compare DNA from their skeletons with DNA from living Indians. In 1999 his team tried to extract DNA from Lagoa Santa bones. When the DNA turned out to be unusable, Pena came up with a second, more unorthodox approach: he decided to look for Lagoa Santa DNA in the Botocudo.

  The Botocudo were an indigenous group that lived a few hundred miles north of what is now Rio de Janeiro. (The name comes from botoque, the derogatory Portuguese term for the big wooden discs that the Botocudo inserted in their lower lips and earlobes, distending them outward.) Although apparently never numerous, they resisted conquest so successfully that in 1801 the Portuguese colonial government formally launched a “just war against the cannibalistic Botocudo.” There followed a century of intermittent strife, which slowly drove the Botocudo to extinction.