In the late 1990s ranchers stripped the forest in the Brazilian state of Acre, across the border from the Beni—only to find earthworks from a previously unknown society. This aerial photo by the archaeologist Martti Pärssinen, which dates from 2003, was the first to be widely disseminated; a Brazilian researcher's gallery of images, which dates from the year before, can be found here.
In 2003, writer Charles C. Mann wrote an article in The Atlantic (later to be turned into a book) that posited a startling idea — that the Amazon rain forest, far from being a natural phenomenon, was a purposefully engineered tree farm planted by humans thousands of years ago. Rogue archaeologists Clark Erickson and William Balée believe the North and South American continents were populated by large and advanced civilizations that pulled off enormous feats of geoengineering, and the rain forest is a result of hundreds of years of fruit and nut tree cultivation by farmers. If we planted it once, that would mean we could plant it again.
Erickson and Balée 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 Balée 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 newtheories 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 thosewho 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.