UNIVERSITY PARK, PENNSYLVANIA—Science News reports that evidence of human occupation of southwestern Amazonia some 10,600 years ago, or several thousand years earlier than previously thought, has been unearthed in Bolivia. Archaeologist José Capriles of Penn State University and his colleagues found burned bits of wood and clay, and the 6,250-year-old remains of hunter-gatherers buried in trash heaps made up of snail shells, fish and small animal bones, and other organic remains, at sites thought to have been regularly occupied for several months at a time. The calcium carbonate in the shells fossilized the human bones, which would have otherwise decomposed in the acidic soil, Capriles explained. He thinks the burials may have marked the claim of a group of hunter-gatherers to seasonal wetlands as the climate became drier between 8,000 and 5,500 years ago. He also noted that the people who lived in these camps may have planted sweet potatoes, cassava, peanuts, and chili peppers as they depleted local resources. To read in-depth about the archaeology of the Amazon, go to “Letter from Peru: Connecting Two Realms.”