There’s a long-running controversy in the world of archaeology regarding how much impact ancient humans had on the evolution of the Amazon rainforest. It’s often assumed that the Amazon as we see it is a pristine wilderness, untouched by human hands since the beginning of time. Looking at the lush rainforest, it’s hard to believe that it hasn’t always been this way. But the journal Nature reported this week that newer research on ancient agriculture in the region has ignited a debate that could affect modern conservation efforts.

The earliest evidence of corn cultivation in the Amazon dates all the way back to about 6,000 years ago, though that evidence is not easily visible to the naked eye. When researchers first started studying the region, it was believed that human settlements were limited to small, primitive groups who left little lasting impact on the landscape; newer studies say that the Amazon was home to complex societies that lived off of agriculture, estimating the area’s population at as high as 10 million in prehistoric times.

The traditional view of the Amazon as a hostile, sparsely populated wilderness unfit for human settlement enabled the colonialist exploitation of its resources. In the 1950s, scientists believed that poor soil quality made agriculture an impossibility in the region. But in the 1980s and 1990s, a series of publications by respected researchers working in the Amazon showed that the lands were in fact cultivated at some point. However, other recent studies have since concluded that the claims of ancient agricultural settlements had been exaggerated, and that human impact was only evident in small areas.

Why does it matter how ancient Amazonian populations lived? It could shape how we understand the current controversies regarding indigenous land claims and conservation. If the Amazon today is not the virgin rainforest it seems to be but rather the result of human intervention, we know that its species are resilient in the face of change. Scientists say that ancient indigenous land management techniques could teach us a great deal about maintaining a healthy balance in this ecosystem.

The debate continues to rage on, now with the help of new, high-tech research tools that let researchers get a bigger picture of remote jungle sites. What they know for sure is that the Amazon rainforest has been in a process of change for thousands of years– and that humans have been a part of that process, for better or for worse.