Anthropologists have uncovered the remnants of a sophisticated network of settlements in the Amazon rainforest that date back to pre-Columbian days, and which challenge notions of what a complex and organized society can look like. The 28 towns and villages found thus far were tucked away in the forest and linked by roads, and may have supported as many as 50,000 people across an area slightly smaller than New Jersey. Says lead researcher Mike Heckenberger:

"These are not cities, but this is urbanism, built around towns.... If we look at your average medieval town or your average Greek polis, most are about the scale of those we find in this part of the Amazon" [Reuters].

Researchers believe that these settlements were first occupied about 1,500 years ago, and say that indicates that the rainforest has been shaped by human habitation much more profoundly than previously realized.

[T]he Western Amazon forest is not, strictly speaking, what could be called "virgin" forest. It is what took over after local cultures were wiped out by European settlers and their diseases and their towns and villages were left untended [New Scientist].

In the report, published in the journal Science [subscription required], researchers describe archaeological evidence of cassava fields near some settlements, as well as earthen dams and artificial ponds that may have been used for fish farms.

Satellite pictures reveal that during that time, the inhabitants carved roads through the jungle; all plaza villages had a major road that ran northeast to southwest along the summer solstice axis and linked to other settlements as much as three miles (five kilometers) away. There were bridges on some of the roads and others had canoe canals running alongside them [Scientific American].

Researchers found the historic sites with the help of

members of the Kuikuro tribe, who are thought to be direct descendents of the people who built the towns [BBC News].

The findings could also guide future developments in the Amazon, researchers say, as the early settlers seem to have maximized limited natural resources without damaging their jungle surroundings; this may

suggest future solutions for supporting the indigenous population in Brazil's state of Mato Grosso and other regions of the Amazon, the paper says [Telegraph].

For an in-depth exploration of these early settlements and their agricultural practices, see the DISCOVER story, "Black Gold of the Amazon."

Image: Science/AAAS