In recent years, anthropologists, archaeologists, geographers and historians reassessing the environmental impact of indigenous cultures in North and Central America inevitably have turned to the tropical forest. And in growing numbers researchers have come to believe that the Amazon basin, too, bears the fingerprints of its original inhabitants. Far from being the timeless, million-year-old wilderness portrayed on calendars, these scientists say, today’s forest is the product of a historical interaction between the environment and human beings. Such claims raise the heckles of many conservationists and ecologists. Amazonia, activists warn, is sliding toward catastrophe so rapidly that saving it must become a global priority, and claiming that the basin comfortably housed large numbers of people for millennia is so irresponsible as to be almost immoral. The Amazon is not wild, archaeologists and anthropologists retort. And claiming that it is will, in its ignorance, worsen the ecological ailments that activists would like to cure. Like their confreres elsewhere in the Americas, Indian societies had built up a remarkable body of knowledge about how to manage and improve their environment. By denying the very possibility of such practices, these researchers say, environmentalists may hasten, rather than halt, the demise of the forest.