Excavations show hunter-gatherers lived in the Amazon more than 10,000 years ago

Foragers may have laid the groundwork for farming’s ascent thousands of years later

FORAGERS ARISE  Human skeletons such as this one, recovered from graves in the southwestern Amazon, contribute to evidence that hunter-gatherers lived in the area from around 10,600 to 4,000 years ago.

J. Capriles/PSU

Hunter-gatherers occupied the southwestern Amazon rainforest by around 10,600 years ago — at least several thousand years earlier than previously thought.

Excavated food remains and human burials at several locations in Bolivia support a scenario in which hunter-gatherers regularly occupied those spots for large parts of the year. The unearthed evidence also indicates that the hunter-gatherers were living in the southwestern Amazon until around 4,000 years ago, anthropological archaeologist José Capriles of Penn State University and colleagues report online April 24 in Science Advances.

If hunter-gatherers developed a preference for living in one place for months at a time, that may have led to the rise of farming societies in the southwestern Amazon around 2,500 years ago, the scientists speculate.

Bolivian forest patch
IN THE THICKET Excavations of a Bolivian site in this forested patch yielded remains of hunter-gatherers who lived there much earlier than scientists had thought. J. Capriles/PSU

Capriles’ team focused on three small, forested mounds of earth located in dry grasslands that flood during rainy months. The researchers uncovered deposits of burned clay and wood bits likely produced by fireplaces of some kind, snail shells and bones of fish and small mammals. Skeletons of five people buried at the three sites were also found. Radiocarbon dating places the ages of these graves at around 6,250 years old or more.

As a drier climate took hold between roughly 8,000 and 5,500 years ago, hunter-gatherers in the southwestern Amazon may have intensified their occupations of campsites near patchy, seasonal wetlands for part of the year. By interring some of their dead at those sites, foraging communities may have claimed that valuable property and nearby wetland resources as theirs, the team suspects.

Bruce Bower has written about the behavioral sciences for Science News since 1984. He writes about psychology, anthropology, archaeology and mental health issues.

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