Huge swaths of the Amazon basin may not have always been the bustling rainforests we see today. Researchers have found evidence that in a few hundred years, the land may have radically switched from a smattering of wide savannahs to the "timeless" rainforests of today.

A study recently published in the Proceedings of the National Academy of Sciences (PNAS) details a new theory as to how ancient peoples who led agricultural-based lives shaped the Amazon basin. After significant geological evidence of ancient earth-works and farming was discovered in past studies, many experts assumed that the Amazonian people literally carved out their lives in the dense jungle, clearing sections of the basin for human settlement.

However, researchers from the University of Reading now suggest that the Amazon basin was not always a dense forest, but also home to wide swaths of grassland thousands of years ago.

This conclusion was reached after an analysis of mud core samples, which were retrieved at various depths, provided a better picture of how the ecosystem in the region had radically changed over time.

According to lead researcher John Carson, his team had headed into the Amazon to determine what kind of crops ancient Amerindian groups grew, and how these practices could have impacted an ancient rainforest. Instead, they found that the rainforest may not have even been there.

"Rather than cutting or burning down huge swathes of jungle, the early Amazonian people simply took advantage of a naturally more open landscape," he said in a statement. "Our analysis shows that they were growing maize and other food crops. They also likely caught fish, and there's evidence from other parts of the Bolivian Amazon for people farming Muscovy ducks and Amazonian river turtles."

Carson and his team suggest that these findings could have some serious implications concerning how the rainforest will truly react to large scale deforestation, especially if the rainforest truly never recovered from such forest clearing in the past.

The study was published in PNAS on July 8.