1491: new revelations of the Americas before Columbus.

Charles C. Mann.

For the woman in the next-door office-.

Cloudlessly, like everything else.

-CCM.

NATIVE AMERICA, 1491 A.D.

Native America, 1491 A.D.

Native America, 1000 A.D.

Massachusett Alliance, 1600 A.D.

Peoples of the Dawnland, 1600 A.D.

Tawantinsuyu: Land of the Four Quarters, 1527 A.D.

Tawantinsuyu: Expansion of the Inka Empire, 14381527 A.D.

Triple Alliance, 1519 A.D.

Paleo-Indian Migration Routes: North America, 10,000 B.C.

Norte Chico: The Americas' First Urban Complex, 30001800 B.C.

Mesoamerica, 1000 B.C.1000 A.D.

Wari and Tiwanaku, 700 A.D.

Moundbuilders, 3400 B.C.1400 A.D.

The American Bottom, 1300 A.D.

The Hundred Years' War: Kaan and Mutal Battle to Control the Maya Heartland, 526682 A.D.

Amazon Basin.

Humanized Landscapes, 1491 A.D.

The seeds of this book date back, at least in part, to 1983, when I wrote an article for Science about a NASA program that was monitoring atmospheric ozone levels. In the course of learning about the program, I flew with a research team in a NASA plane equipped to sample and analyze the atmosphere at thirty thousand feet. At one point the group landed in Merida, in Mexico's Yucatan Peninsula. For some reason the scientists had the next day off, and we all took a decrepit Volkswagen van to the Maya ruins of Chichen Itza. I knew nothing about Mesoamerican culture-I may not even have been familiar with the term "Mesoamerica," which encompasses the area from central Mexico to Panama, including all of Guatemala and Belize, and parts of El Salvador, Honduras, Costa Rica, and Nicaragua, the homeland of the Maya, the Olmec, and a host of other indigenous groups. Moments after we clambered out of the van I was utterly enthralled.

On my own-sometimes for vacation, sometimes on assignment-I returned to Yucatan five or six times, three times with my friend Peter Menzel, a photojournalist. For a German magazine, Peter and I made a twelve-hour drive down a terrible dirt road (thigh-deep potholes, blockades of fallen timber) to the then-unexcavated Maya metropolis of Calakmul. Accompanying us was Juan de la Cruz Briceno, Maya himself, caretaker of another, smaller ruin. Juan had spent twenty years as a chiclero, trekking the forest for weeks on end in search of chicle trees, which have a gooey sap that Indians have dried and chewed for millennia and that in the late nineteenth century became the base of the chewing-gum industry. Around a night fire he told us about the ancient, vine-shrouded cities he had stumbled across in his rambles, and his amazement when scientists informed him that his ancestors had built them. That night we slept in hammocks amid tall, headstone-like carvings that had not been read for more than a thousand years.

My interest in the peoples who walked the Americas before Columbus only snapped into anything resembling focus in the fall of 1992. By chance one Sunday afternoon I came across a display in a college library of the special Columbian quincentenary issue of the Annals of the Association of American Geographers. Curious, I picked up the journal, sank into an armchair, and began to read an article by William Denevan, a geographer at the University of Wisconsin. The article opened with the question, "What was the New World like at the time of Columbus?" Yes, I thought, what was it like? Who lived here and what could have passed through their minds when European sails first appeared on the horizon? I finished Denevan's article and went on to others and didn't stop reading until the librarian flicked the lights to signify closing time.

I didn't know it then, but Denevan and a host of fellow researchers had spent their careers trying to answer these questions. The picture they have emerged with is quite different from what most Americans and Europeans think, and still little known outside specialist circles.

A year or two after I read Denevan's article, I attended a panel discussion at the annual meeting of the American Association for the Advancement of Science. Called something like "New Perspectives on the Amazon," the session featured William Balee of Tulane University. Balee's talk was about "anthropogenic" forests-forests created by Indians centuries or millennia in the past-a concept I'd never heard of before. He also mentioned something that Denevan had discussed: many researchers now believe their predecessors underestimated the number of people in the Americas when Columbus arrived. Indians were more numerous than previously thought, Balee said-much more numerous. Gee, someone ought to put all this stuff together, I thought. It would make a fascinating book.

I kept waiting for that book to appear. The wait grew more frustrating when my son entered school and was taught the same things I had been taught, beliefs I knew had long been sharply questioned. Since nobody else appeared to be writing the book, I finally decided to try it myself. Besides, I was curious to learn more. The book you are holding is the result.

Some things this book is not. It is not a systematic, chronological account of the Western Hemisphere's cultural and social development before 1492. Such a book, its scope vast in space and time, could not be written-by the time the author approached the end, new findings would have been made and the beginning would be outdated. Among those who assured me of this were the very researchers who have spent much of the last few decades wrestling with the staggering diversity of pre-Columbian societies.

Nor is this book a full intellectual history of the recent changes in perspective among the anthropologists, archaeologists, ecologists, geographers, and historians who study the first Americans. That, too, would be impossible, for the ramifications of the new ideas are still rippling outward in too many directions for any writer to contain them in one single work.

Instead, this book explores what I believe to be the three main foci of the new findings: Indian demography (Part I), Indian origins (PartII), and Indian ecology (Part III). Because so many different societies illustrate these points in such different ways, I could not possibly be comprehensive. Instead, I chose my examples from cultures that are among the best documented, or have drawn the most recent attention, or just seemed the most intriguing.

Throughout this book, as the reader already will have noticed, I use the term "Indian" to refer to the first inhabitants of the Americas. No question about it, Indian is a confusing and historically inappropriate name. Probably the most accurate descriptor for the original inhabitants of the Americas is Americans. Actually using it, though, would be risking worse confusion. In this book I try to refer to people by the names they call themselves. The overwhelming majority of the indigenous peoples whom I have met in both North and South America describe themselves as Indians. (For more about nomenclature, see Appendix A, "Loaded Words.") In the mid-1980s I traveled to the village of Hazelton, on the upper Skeena River in the middle of British Columbia. Many of its inhabitants belong to the Gitksan (or Gitxsan) nation. At the time of my visit, the Gitksan had just lodged a lawsuit with the governments of both British Columbia and Canada. They wanted the province and the nation to recognize that the Gitksan had lived there a long time, had never left, had never agreed to give their land away, and had thus retained legal title to about eleven thousand square miles of the province. They were very willing to negotiate, they said, but they were not willing to not be negotiated with.

Flying in, I could see why the Gitksan were attached to the area. The plane swept past the snowy, magnificent walls of the Rocher de Boule Mountains and into the confluence of two forested river valleys. Mist steamed off the land. People were fishing in the rivers for steelhead and salmon even though they were 165 miles from the coast.

The Gitanmaax band of the Gitksan has its headquarters in Hazelton, but most members live in a reserve just outside town. I drove to the reserve, where Neil Sterritt, head of the Gitanmaax council, explained the litigation to me. A straightforward, level-voiced man, he had got his start as a mining engineer and then come back home with his shirtsleeves rolled up, ready for a lengthy bout of legal wrangling. After multiple trials and appeals, the Supreme Court of Canada ruled in 1997 that British Columbia had to negotiate the status of the land with the Gitksan. Talks were still ongoing in 2005, two decades after the lawsuit first began.

After a while Sterritt took me to see 'Ksan, a historical park and art school created in 1970. In the park were several re-created longhouses, their facades covered in the forcefully elegant, black-and-red arcs of Northwest Coast Indian art. The art school trained local Indians in the techniques of translating traditionally derived designs into silk-screen prints. Sterritt left me in a back room of the schoolhouse and told me to look around. There was more in the room than he may have realized, for I quickly found what looked like storage boxes for a number of old and beautiful masks. Beside them was a stack of modern prints, some of which used the same designs. And there were boxes of photographs, old and new alike, many of splendid artworks.

In Northwest Coast art the subjects are flattened and distorted-it's as if they've been reduced from three dimensions to two and then folded like origami. At first I found all the designs hard to interpret, but soon some seemed to pop right out of the surface. They had clean lines that cut space into shapes at once simple and complex: objects tucked into objects, creatures stuffed into their own eyes, humans who were half beast and beasts who were half human-all was metamorphosis and surreal commotion.

A few of the objects I looked at I understood immediately, many I didn't understand at all, some I thought I understood but probably didn't, and some maybe even the Gitksan didn't understand, in the way that most Europeans today can't truly understand the effect of Byzantine art on the spirits of the people who saw it at the time of its creation. But I was delighted by the boldly graphic lines and dazzled by the sense that I was peeking into a vibrant past that I had not known existed and that continued to inform the present in a way I had not realized. For an hour or two I went from object to object, always eager to see more. In assembling this book, I hope to share the excitement I felt then, and have felt many times since.

INTRODUCTION.

Holmberg's Mistake.

A View from Above.

IN THE BENI.

The plane took off in weather that was surprisingly cool for central Bolivia and flew east, toward the Brazilian border. In a few minutes the roads and houses disappeared, and the only traces of human settlement were the cattle scattered over the savanna like sprinkles on ice cream. Then they, too, disappeared. By that time the archaeologists had their cameras out and were clicking away in delight.

Below us lay the Beni, a Bolivian province about the size of Illinois and Indiana put together, and nearly as flat. For almost half the year rain and snowmelt from the mountains to the south and west cover the land with an irregular, slowly moving skin of water that eventually ends up in the province's northern rivers, which are upper tributaries of the Amazon. The rest of the year the water dries up and the bright green vastness turns into something that resembles a desert. This peculiar, remote, often watery plain was what had drawn the researchers' attention, and not just because it was one of the few places on earth inhabited by some people who might never have seen Westerners with cameras.

Clark Erickson and William Balee, the archaeologists, sat up front. Erickson, based at the University of Pennsylvania, worked in concert with a Bolivian archaeologist, who that day was elsewhere, freeing up a seat in the plane for me. Balee, of Tulane, is actually an anthropologist, but as scientists have come to appreciate the ways in which past and present inform each other, the distinction between anthropologists and archaeologists has blurred. The two men differ in build, temperament, and scholarly proclivity, but they pressed their faces to the windows with identical enthusiasm.

Scattered across the landscape below were countless islands of forest, many of them almost-perfect circles-heaps of green in a sea of yellow grass. Each island rose as much as sixty feet above the floodplain, allowing trees to grow that otherwise could not endure the water. The forests were bridged by raised berms, as straight as a rifle shot and up to three miles long. It is Erickson's belief that this entire landscape-thirty thousand square miles or more of forest islands and mounds linked by causeways-was constructed by a technologically advanced, populous society more than a thousand years ago. Balee, newer to the Beni, leaned toward this view but was not yet ready to commit himself.

Erickson and Balee belong to a cohort of scholars that in recent years has radically challenged conventional notions of what the Western Hemisphere was like before Columbus. When I went to high school, in the 1970s, I was taught that Indians came to the Americas across the Bering Strait about thirteen thousand years ago, that they lived for the most part in small, isolated groups, and that they had so little impact on their environment that even after millennia of habitation the continents remained mostly wilderness. Schools still impart the same ideas today. One way to summarize the views of people like Erickson and Balee would be to say that they regard this picture of Indian life as wrong in almost every aspect. Indians were here far longer than previously thought, these researchers believe, and in much greater numbers. And they were so successful at imposing their will on the landscape that in 1492 Columbus set foot in a hemisphere thoroughly marked by humankind.

Given the charged relations between white societies and native peoples, inquiry into Indian culture and history is inevitably contentious. But the recent scholarship is especially controversial. To begin with, some researchers-many but not all from an older generation-deride the new theories as fantasies arising from an almost willful misinterpretation of data and a perverse kind of political correctness. "I have seen no evidence that large numbers of people ever lived in the Beni," Betty J. Meggers, of the Smithsonian Institution, told me. "Claiming otherwise is just wishful thinking." Indeed, two Smithsonian-backed archaeologists from Argentina have argued that many of the larger mounds are natural floodplain deposits; a "small initial population" could have built the remaining causeways and raised fields in as little as a decade. Similar criticisms apply to many of the new scholarly claims about Indians, according to Dean R. Snow, an anthropologist at Pennsylvania State University. The problem is that "you can make the meager evidence from the ethnohistorical record tell you anything you want," he says. "It's really easy to kid yourself." And some have charged that the claims advance the political agenda of those who seek to discredit European culture, because the high numbers seem to inflate the scale of native loss.

Disputes also arise because the new theories have implications for today's ecological battles. Much of the environmental movement is animated, consciously or not, by what geographer William Denevan calls "the pristine myth"-the belief that the Americas in 1491 were an almost untouched, even Edenic land, "untrammeled by man," in the words of the Wilderness Act of 1964, a U.S. law that is one of the founding documents of the global environmental movement. To green activists, as the University of Wisconsin historian William Cronon has written, restoring this long-ago, putatively natural state is a task that society is morally bound to undertake. Yet if the new view is correct and the work of humankind was pervasive, where does that leave efforts to restore nature?

The Beni is a case in point. In addition to building roads, causeways, canals, dikes, reservoirs, mounds, raised agricultural fields, and possibly ball courts, Erickson has argued, the Indians who lived there before Columbus trapped fish in the seasonally flooded grassland. The trapping was not a matter of a few isolated natives with nets, but a society-wide effort in which hundreds or thousands of people fashioned dense, zigzagging networks of earthen fish weirs (fish-corralling fences) among the causeways. Much of the savanna is natural, the result of seasonal flooding. But the Indians maintained and expanded the grasslands by regularly setting huge areas on fire. Over the centuries the burning created an intricate ecosystem of fire-adapted plant species dependent on indigenous pyrophilia. The Beni's current inhabitants still burn, although now it is mostly to maintain the savanna for cattle. When we flew over the region, the dry season had just begun, but mile-long lines of flame were already on the march. Smoke rose into the sky in great, juddering pillars. In the charred areas behind the fires were the blackened spikes of trees, many of them of species that activists fight to save in other parts of Amazonia.

The future of the Beni is uncertain, especially its most thinly settled region, near the border with Brazil. Some outsiders want to develop the area for ranches, as has been done with many U.S. grasslands. Others want to keep this sparsely populated region as close to wilderness as possible. Local Indian groups regard this latter proposal with suspicion. If the Beni becomes a reserve for the "natural," they ask, what international organization would let them continue setting the plains afire? Could any outside group endorse large-scale burning in Amazonia? Instead, Indians propose placing control of the land into their hands. Activists, in turn, regard that idea without enthusiasm-some indigenous groups in the U.S. Southwest have promoted the use of their reservations as repositories for nuclear waste. And, of course, there is all that burning.

HOLMBERG'S MISTAKE.

"Don't touch that tree," Balee said.

I froze. I was climbing a low, crumbly hill and had been about to support myself by grasping a scrawny, almost vine-like tree with splayed leaves. "Triplaris americana," said Balee, an expert in forest botany. "You have to watch out for it." In an unusual arrangement, he said, T. americana plays host to colonies of tiny red ants-indeed, it has trouble surviving without them. The ants occupy minute tunnels just beneath the bark. In return for shelter, the ants attack anything that touches the tree-insect, bird, unwary writer. The venom-squirting ferocity of their attack gives rise to T. americana's local nickname: devil tree.

At the base of the devil tree, exposing its roots, was a deserted animal burrow. Balee scraped out some dirt with a knife, then waved me over, along with Erickson and my son Newell, who were accompanying us. The depression was thick with busted pottery. We could see the rims of plates and what looked like the foot of a teakettle-it was shaped like a human foot, complete with painted toenails. Balee plucked out half a dozen pieces of ceramic: shards of pots and plates, a chipped length of cylindrical bar that may have been part of a pot's support leg. As much as an eighth of the hill, by volume, was composed of such fragments, he said. You could dig almost anywhere on it and see the like. We were clambering up an immense pile of broken crockery.

The pile is known as Ibibate, at fifty-nine feet one of the tallest known forested mounds in the Beni. Erickson explained to me that the pieces of ceramic were probably intended to help build up and aerate the muddy soil for settlement and agriculture. But though this explanation makes sense on engineering grounds, he said, it doesn't make the long-ago actions of the moundbuilders any less mysterious. The mounds cover such an enormous area that they seem unlikely to be the byproduct of waste. Monte Testaccio, the hill of broken pots southeast of Rome, was a garbage dump for the entire imperial city. Ibibate is larger than Monte Testaccio and but one of hundreds of similar mounds. Surely the Beni did not generate more waste than Rome-the ceramics in Ibibate, Erickson argues, indicate that large numbers of people, many of them skilled laborers, lived for a long time on these mounds, feasting and drinking exuberantly all the while. The number of potters necessary to make the heaps of crockery, the time required for labor, the number of people needed to provide food and shelter for the potters, the organization of large-scale destruction and burial-all of it is evidence, to Erickson's way of thinking, that a thousand years ago the Beni was the site of a highly structured society, one that through archaeological investigation was just beginning to come into view.

Accompanying us that day were two Siriono Indians, Chiro Cuellar and his son-in-law Rafael. The two men were wiry, dark, and nearly beardless; walking beside them on the trail, I had noticed small nicks in their earlobes. Rafael, cheerful almost to bumptiousness, peppered the afternoon with comments; Chiro, a local figure of authority, smoked locally made "Marlboro" cigarettes and observed our progress with an expression of amused tolerance. They lived about a mile away, in a little village at the end of a long, rutted dirt road. We had driven there earlier in the day, parking in the shade of a tumbledown school and some old missionary buildings. The structures were clustered near the top of a small hill-another ancient mound. While Newell and I waited by the truck, Erickson and Balee went inside the school to obtain permission from Chiro and the other members of the village council to tramp around. Noticing that we were idle, a couple of Siriono kids tried to persuade Newell and me to look at a young jaguar in a pen, and to give them money for this thrill. After a few minutes, Erickson and Balee emerged with the requisite permission-and two chaperones, Chiro and Rafael. Now, climbing up Ibibate, Chiro observed that I was standing by the devil tree. Keeping his expression deadpan, he suggested that I climb it. Up top, he said, I would find some delicious jungle fruit. "It will be like nothing you have experienced before," he promised.

From the top of Ibibate we were able to see the surrounding savanna. Perhaps a quarter mile away, across a stretch of yellow, waist-high grass, was a straight line of trees-an ancient raised causeway, Erickson said. Otherwise the countryside was so flat that we could see for miles in every direction-or, rather, we could have seen for miles, if the air in some directions had not been filled with smoke.

Afterward I wondered about the relationship of our escorts to this place. Were the Siriono like contemporary Italians living among the monuments of the Roman Empire? I asked Erickson and Balee that question during the drive back.

Their answer continued sporadically through the rest of the evening, as we rode to our lodgings in an unseasonable cold rain and then had dinner. In the 1970s, they said, most authorities would have answered my question about the Siriono in one way. Today most would answer it in another, different way. The difference involves what I came to think of, rather unfairly, as Holmberg's Mistake.

Although the Siriono are but one of a score of Native American groups in the Beni, they are the best known. Between 1940 and 1942 a young doctoral student named Allan R. Holmberg lived among them. He published his account of their lives, Nomads of the Longbow, in 1950. (The title refers to the six-foot bows the Siriono use for hunting.) Quickly recognized as a classic, Nomads remains an iconic and influential text; as filtered through countless other scholarly articles and the popular press, it became one of the main sources for the outside world's image of South American Indians.

The Siriono, Holmberg reported, were "among the most culturally backward peoples of the world." Living in constant want and hunger, he said, they had no clothes, no domestic animals, no musical instruments (not even rattles and drums), no art or design (except necklaces of animal teeth), and almost no religion (the Siriono "conception of the universe" was "almost completely uncrystallized"). Incredibly, they could not count beyond three or make fire (they carried it, he wrote, "from camp to camp in a [burning] brand"). Their poor lean-tos, made of haphazardly heaped palm fronds, were so ineffective against rain and insects that the typical band member "undergoes many a sleepless night during the year." Crouched over meager campfires during the wet, buggy nights, the Siriono were living exemplars of primitive humankind-the "quintessence" of "man in the raw state of nature," as Holmberg put it. For millennia, he thought, they had existed almost without change in a landscape unmarked by their presence. Then they encountered European society and for the first time their history acquired a narrative flow.

Holmberg was a careful and compassionate researcher whose detailed observations of Siriono life remain valuable today. And he bravely surmounted trials in Bolivia that would have caused many others to give up. During his months in the field he was always uncomfortable, usually hungry, and often sick. Blinded by an infection in both eyes, he walked for days through the forest to a clinic, holding the hand of a Siriono guide. He never fully recovered his health. After his return, he became head of the anthropology department at Cornell University, from which position he led its celebrated efforts to alleviate poverty in the Andes.

Nonetheless, he was wrong about the Siriono. And he was wrong about the Beni, the place they inhabited-wrong in a way that is instructive, even exemplary.

Before Columbus, Holmberg believed, both the people and the land had no real history. Stated so baldly, this notion-that the indigenous peoples of the Americas floated changelessly through the millennia until 1492-may seem ludicrous. But flaws in perspective often appear obvious only after they are pointed out. In this case they took decades to rectify.

The Bolivian government's instability and fits of anti-American and anti-European rhetoric ensured that few foreign anthropologists and archaeologists followed Holmberg into the Beni. Not only was the government hostile, the region, a center of the cocaine trade in the 1970s and 1980s, was dangerous. Today there is less drug trafficking, but smugglers' runways can still be seen, cut into remote patches of forest. The wreck of a crashed drug plane sits not far from the airport in Trinidad, the biggest town in the province. During the drug wars "the Beni was neglected, even by Bolivian standards," according to Robert Langstroth, a geographer and range ecologist in Wisconsin who did his dissertation fieldwork there. "It was a backwater of a backwater." Gradually a small number of scientists ventured into the region. What they learned transformed their understanding of the place and its people.

Just as Holmberg believed, the Siriono were among the most culturally impoverished people on earth. But this was not because they were unchanged holdovers from humankind's ancient past but because smallpox and influenza laid waste to their villages in the 1920s. Before the epidemics at least three thousand Siriono, and probably many more, lived in eastern Bolivia. By Holmberg's time fewer than 150 remained-a loss of more than 95 percent in less than a generation. So catastrophic was the decline that the Siriono passed through a genetic bottleneck. (A genetic bottleneck occurs when a population becomes so small that individuals are forced to mate with relatives, which can produce deleterious hereditary effects.) The effects of the bottleneck were described in 1982, when Allyn Stearman of the University of Central Florida became the first anthropologist to visit the Siriono since Holmberg. Stearman discovered that the Siriono were thirty times more likely to be born with clubfeet than typical human populations. And almost all the Siriono had unusual nicks in their earlobes, the traits I had noticed on the two men accompanying us.

Even as the epidemics hit, Stearman learned, the group was fighting the white cattle ranchers who were taking over the region. The Bolivian military aided the incursion by hunting down the Siriono and throwing them into what were, in effect, prison camps. Those released from confinement were forced into servitude on the ranches. The wandering people Holmberg traveled with in the forest had been hiding from their abusers. At some risk to himself, Holmberg tried to help them, but he never fully grasped that the people he saw as remnants from the Paleolithic Age were actually the persecuted survivors of a recently shattered culture. It was as if he had come across refugees from a Nazi concentration camp, and concluded that they belonged to a culture that had always been barefoot and starving.

Far from being leftovers from the Stone Age, in fact, the Siriono are probably relative newcomers to the Beni. They speak a language in the Tupi-Guarani group, one of the most important Indian language families in South America but one not common in Bolivia. Linguistic evidence, first weighed by anthropologists in the 1970s, suggests that they arrived from the north as late as the seventeenth century, about the time of the first Spanish settlers and missionaries. Other evidence suggests they may have come a few centuries earlier; Tupi-Guaranispeaking groups, possibly including the Siriono, attacked the Inka empire in the early sixteenth century. No one knows why the Siriono moved in, but one reason may be simply that the Beni then was little populated. Not long before, the previous inhabitants' society had disintegrated.

To judge by Nomads of the Longbow, Holmberg did not know of this earlier culture-the culture that built the causeways and mounds and fish weirs. He didn't see that the Siriono were walking through a landscape that had been shaped by somebody else. A few European observers before Holmberg had remarked upon the earthworks' existence, though some doubted that the causeways and forest islands were of human origin. But they did not draw systematic scholarly attention until 1961, when William Denevan came to Bolivia. Then a doctoral student, he had learned of the region's peculiar landscape during an earlier stint as a cub reporter in Peru and thought it might make an interesting topic for his thesis. Upon arrival he discovered that oil-company geologists, the only scientists in the area, believed the Beni was thick with the remains of an unknown civilization.

Convincing a local pilot to push his usual route westward, Denevan examined the Beni from above. He observed exactly what I saw four decades later: isolated hillocks of forest; long raised berms; canals; raised agricultural fields; circular, moat-like ditches; and odd, zigzagging ridges. "I'm looking out of one of these DC-3 windows, and I'm going berserk in this little airplane," Denevan said to me. "I knew these things were not natural. You just don't have that kind of straight line in nature." As Denevan learned more about the landscape, his amazement grew. "It's a completely humanized landscape," he said. "To me, it was clearly the most exciting thing going on in the Amazon and adjacent areas. It may be the most important thing in all of South America, I think. Yet it was practically untouched" by scientists. It is still almost untouched-there aren't even any detailed maps of the earthworks and canals.

Beginning as much as three thousand years ago, this long-ago society-Erickson believes it was probably founded by the ancestors of an Arawak-speaking people now called the Mojo and the Baure-created one of the largest, strangest, and most ecologically rich artificial environments on the planet. These people built up the mounds for homes and farms, constructed the causeways and canals for transportation and communication, created the fish weirs to feed themselves, and burned the savannas to keep them clear of invading trees. A thousand years ago their society was at its height. Their villages and towns were spacious, formal, and guarded by moats and palisades. In Erickson's hypothetical reconstruction, as many as a million people may have walked the causeways of eastern Bolivia in their long cotton tunics, heavy ornaments dangling from their wrists and necks.

Flying over eastern Bolivia in the early 1960s, the young geographer William Denevan was amazed to see that the landscape (bottom)-home to nothing but cattle ranches for generations-still bore evidence that it had once been inhabited by a large, prosperous society, one whose very existence had been forgotten. Incredibly, such discoveries are still being made. In 2002 and 2003, Finnish and Brazilian researchers revealed the remains of dozens of geometrical earthworks (top) in the western Brazilian state of Acre where the forest had just been cleared for cattle ranches.

Today, hundreds of years after this Arawak culture passed from the scene, the forest on and around Ibibate mound looks like the classic Amazon of conservationists' dreams: lianas thick as a human arm, dangling blade-like leaves more than six feet long, smooth-boled Brazil nut trees, thick-bodied flowers that smell like warm meat. In terms of species richness, Balee told me, the forest islands of Bolivia are comparable to any place in South America. The same is true of the Beni savanna, it seems, with its different complement of species. Ecologically, the region is a treasure, but one designed and executed by human beings. Erickson regards the landscape of the Beni as one of humankind's greatest works of art, a masterpiece that until recently was almost completely unknown, a masterpiece in a place with a name that few people outside Bolivia would recognize.

"EMPTY OF MANKIND AND ITS WORKS"

The Beni was no anomaly. For almost five centuries, Holmberg's Mistake-the supposition that Native Americans lived in an eternal, unhistoried state-held sway in scholarly work, and from there fanned out to high school textbooks, Hollywood movies, newspaper articles, environmental campaigns, romantic adventure books, and silk-screened T-shirts. It existed in many forms and was embraced both by those who hated Indians and those who admired them. Holmberg's Mistake explained the colonists' view of most Indians as incurably vicious barbarians; its mirror image was the dreamy stereotype of the Indian as a Noble Savage. Positive or negative, in both images Indians lacked what social scientists call agency-they were not actors in their own right, but passive recipients of whatever windfalls or disasters happenstance put in their way.

The Noble Savage dates back as far as the first full-blown ethnography of American indigenous peoples, Bartolome de Las Casas's Apologetica Historia Sumaria, written mainly in the 1530s. Las Casas, a conquistador who repented of his actions and became a priest, spent the second half of his long life opposing European cruelty in the Americas. To his way of thinking, Indians were natural creatures who dwelt, gentle as cows, in the "terrestrial paradise." In their prelapsarian innocence, he believed, they had been quietly waiting-waiting for millennia-for Christian instruction. Las Casas's contemporary, the Italian commentator Pietro Martire d'Anghiera, shared these views. Indians, he wrote (I quote the English translation from 1556), "lyve in that goulden world of whiche owlde writers speake so much," existing "simplye and innocentlye without inforcement of lawes."

In our day, beliefs about Indians' inherent simplicity and innocence refer mainly to their putative lack of impact on the environment. This notion dates back at least to Henry David Thoreau, who spent much time seeking "Indian wisdom," an indigenous way of thought that supposedly did not encompass measuring or categorizing, which he viewed as the evils that allowed human beings to change Nature. Thoreau's ideas continue to be influential. In the wake of the first Earth Day in 1970, a group named Keep America Beautiful, Inc., put up billboards that portrayed an actor in Indian dress quietly weeping over polluted land. The campaign was enormously successful. For almost a decade the image of the crying Indian appeared around the world. Yet though Indians here were playing a heroic role, the advertisement still embodied Holmberg's Mistake, for it implicitly depicted Indians as people who never changed their environment from its original wild state. Because history is change, they were people without history.

Las Casas's anti-Spanish views met with such harsh attacks that he instructed his executors to publish the Apologetica Historia forty years after his death (he died in 1566). In fact, the book did not appear in complete form until 1909. As the delay suggests, polemics for the Noble Savage tended to meet with little sympathy in the eighteenth and nineteenth centuries. Emblematic was the U.S. historian George Bancroft, dean of his profession, who argued in 1834 that before Europeans arrived North America was "an unproductive waste...Its only inhabitants were a few scattered tribes of feeble barbarians, destitute of commerce and of political connection." Like Las Casas, Bancroft believed that Indians had existed in societies without change-except that Bancroft regarded this timelessness as an indication of sloth, not innocence.

In different forms Bancroft's characterization was carried into the next century. Writing in 1934, Alfred L. Kroeber, one of the founders of American anthropology, theorized that the Indians in eastern North America could not develop-could have no history-because their lives consisted of "warfare that was insane, unending, continuously attritional." Escaping the cycle of conflict was "well-nigh impossible," he believed. "The group that tried to shift its values from war to peace was almost certainly doomed to early extinction."*1 Kroeber conceded that Indians took time out from fighting to grow crops, but insisted that agriculture "was not basic to life in the East; it was an auxiliary, in a sense a luxury." As a result, "Ninety-nine per cent or more of what [land] might have been developed remained virgin."

Four decades later, Samuel Eliot Morison, twice a Pulitzer Prize winner, closed his two-volume European Discovery of America with the succinct claim that Indians had created no lasting monuments or institutions. Imprisoned in changeless wilderness, they were "pagans expecting short and brutish lives, void of any hope for the future." Native people's "chief function in history," the British historian Hugh Trevor-Roper, Baron Dacre of Glanton, proclaimed in 1965, "is to show to the present an image of the past from which by history it has escaped."

Textbooks reflected academic beliefs faithfully. In a survey of U.S. history schoolbooks, the writer Frances Fitzgerald concluded that the characterization of Indians had moved, "if anything, resolutely backward" between the 1840s and the 1940s. Earlier writers thought of Indians as important, though uncivilized, but later books froze them into a formula: "lazy, childlike, and cruel." A main textbook of the 1940s devoted only a "few paragraphs" to Indians, she wrote, "of which the last is headed 'The Indians Were Backward.'"

These views, though less common today, continue to appear. The 1987 edition of American History: A Survey, a standard high school textbook by three well-known historians, summed up Indian history thusly: "For thousands of centuries-centuries in which human races were evolving, forming communities, and building the beginnings of national civilizations in Africa, Asia, and Europe-the continents we know as the Americas stood empty of mankind and its works." The story of Europeans in the New World, the book informed students, "is the story of the creation of a civilization where none existed."

It is always easy for those living in the present to feel superior to those who lived in the past. Alfred W. Crosby, a University of Texas historian, noted that many of the researchers who embraced Holmberg's Mistake lived in an era when the driving force of events seemed to be great leaders of European descent and when white societies appeared to be overwhelming nonwhite societies everywhere. Throughout all of the nineteenth and much of the twentieth century, nationalism was ascendant, and historians identified history with nations, rather than with cultures, religions, or ways of life. But the Second World War taught the West that non-Westerners-the Japanese, in this instance-were capable of swift societal change. The rapid disintegration of European colonial empires further adumbrated the point. Crosby likened the effects of these events on social scientists to those on astronomers from "the discovery that the faint smudges seen between stars on the Milky Way were really distant galaxies."

Meanwhile, new disciplines and new technologies were creating new ways to examine the past. Demography, climatology, epidemiology, economics, botany, and palynology (pollen analysis); molecular and evolutionary biology; carbon-14 dating, ice-core sampling, satellite photography, and soil assays; genetic microsatellite analysis and virtual 3-D fly-throughs-a torrent of novel perspectives and techniques cascaded into use. And when these were employed, the idea that the only human occupants of one-third of the earth's surface had changed little for thousands of years began to seem implausible. To be sure, some researchers have vigorously attacked the new findings as wild exaggerations. ("We have simply replaced the old myth [of untouched wilderness] with a new one," scoffed geographer Thomas Vale, "the myth of the humanized landscape.") But after several decades of discovery and debate, a new picture of the Americas and their original inhabitants is emerging.

Advertisements still celebrate nomadic, ecologically pure Indians on horseback chasing bison in the Great Plains of North America, but at the time of Columbus the great majority of Native Americans could be found south of the Rio Grande. They were not nomadic, but built up and lived in some of the world's biggest and most opulent cities. Far from being dependent on big-game hunting, most Indians lived on farms. Others subsisted on fish and shellfish. As for the horses, they were from Europe; except for llamas in the Andes, the Western Hemisphere had no beasts of burden. In other words, the Americas were immeasurably busier, more diverse, and more populous than researchers had previously imagined.

And older, too.

THE OTHER NEOLITHIC REVOLUTIONS.

For much of the last century archaeologists believed that Indians came to the Americas through the Bering Strait about thirteen thousand years ago at the tail end of the last Ice Age. Because the sheets of polar ice locked up huge amounts of water, sea levels around the world fell about three hundred feet. The shallow Bering Strait became a wide land bridge between Siberia and Alaska. In theory, paleo-Indians, as they are called, simply walked across the fifty-five miles that now separate the continents. C. Vance Haynes, an archaeologist at the University of Arizona, put the crowning touches on the scheme in 1964, when he noted evidence that at just the right time-that is, about thirteen thousand years ago-two great glacial sheets in northwest Canada parted, leaving a comparatively warm, ice-free corridor between them. Down this channel paleo-Indians could have passed from Alaska to the more habitable regions in the south without having to hike over the ice pack. At the time, the ice pack extended two thousand miles south of the Bering Strait and was almost devoid of life. Without Haynes's ice-free corridor, it is hard to imagine how humans could have made it to the south. The combination of land bridge and ice-free corridor occurred only once in the last twenty thousand years, and lasted for just a few hundred years. And it happened just before the emergence of what was then the earliest known culture in the Americas, the Clovis culture, so named for the town in New Mexico where its remains were first definitely observed. Haynes's exposition made the theory seem so ironclad that it fairly flew into the textbooks. I learned it when I attended high school. So did my son, thirty years later.

In 1997 the theory abruptly came unglued. Some of its most ardent partisans, Haynes among them, publicly conceded that an archaeological dig in southern Chile had turned up compelling evidence of human habitation more than twelve thousand years ago. And because these people lived seven thousand miles south of the Bering Strait, a distance that presumably would have taken a long time to traverse, they almost certainly arrived before the ice-free corridor opened up. (In any case, new research had cast doubt on the existence of that corridor.) Given the near impossibility of surpassing the glaciers without the corridor, some archaeologists suggested that the first Americans must have arrived twenty thousand years ago, when the ice pack was smaller. Or even earlier than that-the Chilean site had suggestive evidence of artifacts more than thirty thousand years old. Or perhaps the first Indians traveled by boat, and didn't need the land bridge. Or maybe they arrived via Australia, passing the South Pole. "We're in a state of turmoil," the consulting archaeologist Stuart Fiedel told me. "Everything we knew is now supposed to be wrong," he added, exaggerating a little for effect.

No consensus has emerged, but a growing number of researchers believe that the New World was occupied by a single small group that crossed the Bering Strait, got stuck on the Alaska side, and straggled to the rest of the Americas in two or three separate groups, with the ancestors of most modern Indians making up the second group. Researchers differ on the details; some scientists have theorized that the Americas may have been hit with as many as five waves of settlement before Columbus, with the earliest occurring as much as fifty thousand years ago. In most versions, though, today's Indians are seen as relative latecomers.

Indian activists dislike this line of reasoning. "I can't tell you how many white people have told me that 'science' shows that Indians were just a bunch of interlopers," Vine Deloria Jr., a political scientist at the University of Colorado at Boulder, said to me. Deloria is the author of many books, including Red Earth, White Lies, a critique of mainstream archaeology. The book's general tenor is signaled by its index; under "science," the entries include "corruption and fraud and," "Indian explanations ignored by," "lack of proof for theories of," "myth of objectivity of," and "racism of." In Deloria's opinion, archaeology is mainly about easing white guilt. Determining that Indians superseded other people fits neatly into this plan. "If we're only thieves who stole our land from someone else," Deloria said, "then they can say, 'Well, we're just the same. We're all immigrants here, aren't we?'"

The moral logic of the we're-all-immigrants argument that Deloria cites is difficult to parse; it seems to be claiming that two wrongs make a right. Moreover, there's no evidence that the first "wrong" was a wrong-nothing is known about the contacts among the various waves of paleo-Indian migration. But in any case whether most of today's Native Americans actually arrived first or second is irrelevant to an assessment of their cultural achievements. In every imaginable scenario, they left Eurasia before the first whisper of the Neolithic Revolution.

The Neolithic Revolution is the invention of farming, an event whose significance can hardly be overstated. "The human career," wrote the historian Ronald Wright, "divides in two: everything before the Neolithic Revolution and everything after it." It began in the Middle East about eleven thousand years ago. In the next few millennia the wheel and the metal tool sprang up in the same area. The Sumerians put these inventions together, added writing, and in the third millennium B.C. created the first great civilization. Every European and Asian culture since, no matter how disparate in appearance, stands in Sumer's shadow. Native Americans, who left Asia long before agriculture, missed out on the bounty. "They had to do everything on their own," Crosby said to me. Remarkably, they succeeded.

Researchers have long known that a second, independent Neolithic Revolution occurred in Mesoamerica. The exact timing is uncertain-archaeologists keep pushing back the date-but it is now thought to have occurred about ten thousand years ago, not long after the Middle East's Neolithic Revolution. In 2003, though, archaeologists discovered ancient seeds from cultivated squashes in coastal Ecuador, at the foot of the Andes, which may be older than any agricultural remains in Mesoamerica-a third Neolithic Revolution. This Neolithic Revolution probably led, among many other things, to the cultures in the Beni. The two American Neolithics spread more slowly than their counterpart in Eurasia, possibly because Indians in many places had not had the time to build up the requisite population density, and possibly because of the extraordinary nature of the most prominent Indian crop, maize.*2 The ancestors of wheat, rice, millet, and barley look like their domesticated descendants; because they are both edible and highly productive, one can easily imagine how the idea of planting them for food came up. Maize can't reproduce itself, because its kernels are securely wrapped in the husk, so Indians must have developed it from some other species. But there are no wild species that resemble maize. Its closest genetic relative is a mountain grass called teosinte that looks strikingly different-for one thing, its "ears" are smaller than the baby corn served in Chinese restaurants. No one eats teosinte, because it produces too little grain to be worth harvesting. In creating modern maize from this unpromising plant, Indians performed a feat so improbable that archaeologists and biologists have argued for decades over how it was achieved. Coupled with squash, beans, and avocados, maize provided Mesoamerica with a balanced diet, one arguably more nutritious than its Middle Eastern or Asian equivalent. (Andean agriculture, based on potatoes and beans, and Amazonian agriculture, based on manioc [cassava], had wide impact but on a global level were less important than maize.) About seven thousand years elapsed between the dawn of the Middle Eastern Neolithic and the establishment of Sumer. Indians navigated the same path in somewhat less time (the data are too sketchy to be more precise). Pride of place must go to the Olmec, the first technologically complex culture in the hemisphere. Appearing in the narrow "waist" of Mexico about 1800 B.C., they lived in cities and towns centered on temple mounds. Strewn among them were colossal male heads of stone, many six feet tall or more, with helmet-like headgear, perpetual frowns, and somewhat African features, the last of which has given rise to speculation that Olmec culture was inspired by voyagers from Africa. The Olmec were but the first of many societies that arose in Mesoamerica in this epoch. Most had religions that focused on human sacrifice, dark by contemporary standards, but their economic and scientific accomplishments were bright. They invented a dozen different systems of writing, established widespread trade networks, tracked the orbits of the planets, created a 365-day calendar (more accurate than its contemporaries in Europe), and recorded their histories in accordion-folded "books" of fig tree bark paper.