You can’t see a thing from ground level. But take a bunch of satellite images and the mostly-unexplored Brazilian state of Mato Grosso turns out to be unexpectedly densely populated, with 81 seven hundred year old pre-Columbian settlements clearly visible. More interesting still, they weren’t near large rivers but built near smaller streams, smashing the theory that the pre-Columbians lived on fertile flood plains and left most of the dense surrounding forest uninhabited.
There’s more. When the researchers’ fired up their computer model to find out how many people are likely to have lived in the region in pre-Colombian times and the answer was an extraordinary ‘up to a million people’. And that’s many, many more than anyone has predicted before. And it suggests the Amazon was not sparsely populated and pristine back then after all. It was a hub of human activity.
All 81 settlements pre-date the arrival of Europeans and all consisted of fortified ceremonial villages and earthworks laid out either in squares, circulars or hexagons. 24 of the sites were also double-checked from the ground and proved representative of the region. The team found bits of pottery, polished stone axes and charcoal-rich soil, all revealing long-term human habitation and dating back to 1410 – 1460 AD.
It looks like human populations in these regions were actually quite large. The research hints that similar settlements might turn up over a vast area of the southern Amazon measuring 154,000 square miles, which may have supported anything from half a million to a million people, which in turn means previous estimates of the population of the Amazon in pre-Colombian times were probably way too low. On the other hand the region is so vast that it can easily swallow up a couple of million people without a trace, so the population wasn’t exactly dense by modern standards.
Most of the Amazon hasn’t been excavated yet, so it’ll be fascinating to see what else is uncovered by archaeologists.