To the untrained eye, all evidence here in the heart of the Amazon signals virgin forest, untouched by man for time immemorial – from the ubiquitous fruit palms to the cry of howler monkeys, from the air thick with mosquitoes to the unruly tangle of jungle vines.
Archaeologists, many of them Americans, say the opposite is true: This patch of forest, and many others across the Amazon, was instead home to an advanced, even spectacular civilization that managed the forest and enriched infertile soils to feed thousands.
The findings are discrediting a once-bedrock theory of archaeology that long held that the Amazon, unlike much of the Americas, was a historical black hole, its environment too hostile and its earth too poor to have ever sustained big, sedentary societies. Only small and primitive hunter-gatherer tribes, the assumption went, could ever have eked out a living in an unforgiving environment.
But scientists now believe that instead of stone-age tribes, like the groups that occasionally emerge from the forest today, the Indians who inhabited the Amazon centuries ago numbered as many as 20 million, far more people than live here today.