An international team of researchers has discovered that humans settled in Southwest Amazonia and even experimented with agriculture much earlier than previously thought. They published their study in Science Advances.

The assistant professor of anthropology, Jose Capriles, said that they have long been aware that complex societies emerged in Llanos de Moxos in southwestern Amazonia, Bolivia, around 2,500 years ago, but new evidence by researches suggests that humans first settled in the region up to 10,000 years ago during the early Holocene period.

The assistant professor pointed out further that these groups of people were hunter-gatherers. However, their data reveal that they were beginning to deplete their local resources and establish territorial behaviors, perhaps driving them to start domesticating plants including sweet potatoes, cassava, peanuts, and chili peppers as a way to acquire food.

This team of archaeologists carried out their study on three forest islands which are Isla del Tesoro, La Chacra and San Pablo, all within the seasonally flooded savanna of the Llanos de Moxos in northern Bolivia.

Capriles stated further that these islands are elevated above the surrounding savanna, so they do not flood during the rainy season. They believe that people were using these sites recurrently as seasonal camps, especially during the long rainy seasons when most of the Llanos de Moxos become flooded.

When the archaeologists excavated the forest islands, they discovered human skeletons that had been intentionally buried in a manner unlike that of typical hunter-gatherers and instead were more akin to the behaviors of complex societies, characterized by political hierarchy and the production of food.

Another thing Capriles noticed in the research was that if these were highly mobile hunter-gatherers, one would not expect them to bury their dead in specific places. But that wasn't the case as they would leave their dead wherever they died.

Also, he noted that it is rare to find human or even archaeological remains that predate the use of fired pottery in the region. Talking about the soils, he said that the soils tend to be very acidic which often makes the preservation of organic remains impoverished. Also, organic matter depreciates rapidly in tropical settings and this region completely lacks any rock for making stone tools, so even those are not available to study.

Due to the lack of direct evidence in the first study of these archaeological sites in 2013, several archaeologists were skeptical about our findings. It is hard for them to believe that those forest islands were early Holocene archaeological sites. The current study offers definitive and robust evidence of the anthropocentric origin of these sites because the archaeological excavations uncovered first Holocene human burials. These proofs are authoritative of the antiquity and background of these sites.