Humans Explored the Amazon Much Earlier Than Previously Thought
New research published in the journal Plos One has revealed that humans explored the harsh environment of the western Amazon as early as 10,000 years ago, much earlier than previously thought. The findings alter the map of early human occupations in South America.
Evidence came from a detailed study of small, forested mounds of earth known as ‘forest islands’, which dot the lowlands in the tropical savannah region in the Bolivian Amazon. It was believed that the forest islands were formed naturally by shifting rivers or long-term termite mounds. However, the scientists discovered that they were actually formed from massive piles of freshwater snail shells left my human settlers more than 10,000 years ago, according to carbon dating.
Samples of soil collected from the three mounds revealed they were made of a dense collection of shells, bones and charcoal. They apparently formed in two phases — an older layer made up primarily of the shells of freshwater apple snails as well as the bones of deer, fish, reptiles and birds, and an overlying layer composed of organic refuse containing pottery, bone tools and human bones.
Separating the two layers is a thin layer rich in pieces of burnt clay and earth. "My first impression is that it could be made of fragments of hearths, like ovens," said researcher Umberto Lombardo, a geographer at the University of Bern in Switzerland. "Indigenous people in the region still cook in such ovens made of clay."
The researchers suggest that hunters and gatherers brought prey there for preparation, cooking and eating; shells and other artefacts built up into mounds over approximately 6,000 years of human use. The hunter-gatherers may have eventually abandoned these sites as the climate shifted toward wetter conditions later.
The findings also have deeper implications and add to the hotly debated topic about the first humans that arrived in the Americas. Current belief is that the Clovis culture made up the first Americans and arrived about 13,000 years ago. However, scientists have recently uncovered evidence that humans were in the New World more than 14,000 years ago.
"Our discovery shows that people occupied the Llanos de Moxos in the Bolivian Amazon at least 10,500 years ago," Lombardo said. "To reach this location, people had to travel 6,000 kilometres if they came from the Atlantic coast, or they had to cross the Andes if they came from the Pacific Coast. This suggests that either they moved and adapted to new environments extremely fast or they started their journey quite a long time ago."
While archaeologists have been refusing for around 50 years to abandon the theory that the Clovis culture was the first, emerging evidence may soon challenge scientists to abandon old beliefs and start focusing on piecing together a different story.