UF Researchers Find Amazon Once Home To Large, Complex Settlements

September 18, 2003

GAINESVILLE, Fla. — The Amazon, that massive rain forest that evokes images of primordial jungle and nomadic tribes, once supported settlements of thousands of people who lived in villages connected by an ancient version of interstates and interspersed with fields, moats and bridges.

So says a team of University of Florida anthropologists who worked hand-in-hand with members of an indigenous Amazonian tribe to identify and map out two large ancient settlements now overgrown by jungle. Each settlement in the remote region of North Central Brazil was occupied from as early as A.D. 800 until about 1600 and was composed of eight to 12 villages connected with roads – some as wide as 50 yards – and dotted with causeways, plazas, and other structures or earthworks.

The research, set to appear Friday in the journal Science, is the latest evidence contradicting the traditional notion that the Amazon was a pristine, sparsely inhabited wilderness before the first colonialists arrived after 1492. By integrating conventional archaeological practices with satellite-based mapping techniques, and by tapping the current knowledge and practices of descendants of the settlements’ ancient inhabitants, the work also sheds light on a region considered something of an archaeological black hole – despite a size nearly equal to that of the continental United States.

“This place had an economy that supported a large number of people in multiple large villages integrated across the region into a grid-like system,” said Michael Heckenberger, a UF professor of anthropology and the lead author of the paper. “Their rotational agricultural and settlement cycle essentially transformed the entire natural landscape.”

Jim Petersen, a professor of anthropology at the University of Vermont, called the findings “outstanding and very important.”

“This research provides some of the very first concrete evidence of large, socially complex, politically stratified Amerindian societies in the Amazon,” he said. “It suggests…the Amazon provided the context for a previously unknown degree of cultural elaboration, or fluorescence.”

Anthropologists have uncovered evidence of significant settlements elsewhere in South America. But the UF research in the Upper Xingu region in Brazil’s state of Mato Grosso is the most concrete evidence to date of large communities thriving in tropical Amazonian rain forest, Heckenberger said. The area remains occupied today by a people known as the Xinguano, who are divided into smaller groups or tribes with similar customs and practices.

Heckenberger and six colleagues, including two members of the native Kuikuro tribe who could neither read nor write but proved adept field researchers, identified 19 villages in two large clusters in a 386-square-mile study area. They found two- to three-mile broad, straight roads connected the villages in each cluster, part of an “elaborate regional plan,” the scientists report.

“The earthworks include excavated ditches in and around ancient settlements, linear mounds or ‘curbs’ positioned at the margins of major roads, and circular plazas and bridges, artificial river obstructions and ponds, raised causeways, canals and other structures, many of which are still in use today,” they write.

The villages were arranged in a “galactic” pattern around a hub that did not appear to have been occupied and probably was ceremonial, Heckenberger said. The biggest villages had residential areas as large as 200 acres, and the clusters supported populations of 2,500 to 5,000. “Virtually the entire area in and between major settlements was carefully engineered and managed,” the authors write.

Heckenberger said scientists have long believed the Amazon’s rain forest terrain is ecologically incapable of supporting the number of people that apparently lived in the large settlements. For example, they thought that manioc or cassava, a potato-like root crop that serves as a staple in the region, didn’t contain enough nutrients to support large populations. But he said pots unearthed in the study, and observations of the contemporary Kuikuro practices, show the root is prepared in a way that provides ample nutrition when consumed with other regional foods, such as fish.

“What we’re saying is that they had a lot of fish, and they had the means available to harvest lots of fish and that the way they cooked manioc may retain more nutrients than we thought,” he said.

Since he began working with the Kuikuro in 1991, Heckenberger has lived almost two full years with the tribe. He said the people were familiar with the earthworks and other peculiarities of their landscape but didn’t know their ancestors created the structures. Once the Kuikuro understood the proper context, he said, they became adept at using their knowledge to point out sites or features the U.S. researchers struggled to find. For example, they knew immediately that certain plants grow in “dark earth,” or “egepe” soils in their language, which are richer soils indicating past human activity.

Heckenberger mapped out some of the sites in 1993, but cutting the surveying corridors and other aspects of the work was so laborious he wasn’t able to map the roads and discover the wheel-like or galactic pattern at the time. After 1999, however, with the availability of highly accurate Global Positioning System technology, the team could map sites much more quickly. “What took weeks if not months to map, I can now do in a matter of days,” he said.

The Upper Xingu region is so remote that Europeans did not reach the area until the mid-1700s, more than two hundred years after the first colonists arrived in Brazil, Heckenberger said. By then, many of the villages had been largely abandoned, the people most likely decimated years earlier by the spread of European diseases such as smallpox, measles and influenza, he said.