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.
“There is a gigantic footprint in the forest,” said Augusto Oyuela-Caycedo, 49, a Colombian-born professor at the University of Florida who is working this swath in northeast Peru.
Stooping over a man-made Indian mound on a recent day, he picked up shards of ceramics and dark, nutrient-rich earth made fertile hundreds of years ago by human hands. “All you can see is an artifact of the past,” he said. “It’s a product of human actions,” he said.
The evidence is not just here outside tiny San Martin de Samiria, an indigenous hamlet hours by speed boat from the jungle city of Iquitos. It is found across Amazonia.
It looks like Colonel Percy Harrison Fawcett was on to something.