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Ancient WorldsAncient Worlds

Meet the Extreme Geoengineers of Ancient Times

ByAllison EckNOVA NextNOVA Next
This is no simulation.

Editor’s Note: This article was originally published in an edition of NOVA’s email newsletter, NOVA Lens, and has now been repurposed for NOVA Next. Sign up for NOVA Lens here (select “NOVA Newsletters”).

This might look like an otherworldly video game, but it’s not. What you’re looking at is the outline of an ancient Mayan megalopolis.

“We found five new cities,” said Francisco Estrada-Belli, a research assistant professor at Tulane University.

Estrada-Belli and 29 other scientists discovered 60,000 previously unknown Mayan buildings, homes, ceremonial structures, agricultural adaptations, and pyramids using LIDAR—a technology that uses pulsed laser light to reveal the shape of objects, including those obscured by dense forest canopies. “This is the largest archaeological survey done by LIDAR in the whole world,” he said.

Thick Central American jungles conceal many remnants of ancient Mayan cities from view. People—including looters—have stumbled across these sites over the years, though more recently LIDAR has allowed professionals to rapidly analyze the landscape without harming it. What’s different about this survey, in particular, is its enormous scale. “There’s more of everything than we would have predicted,” said Marcello Canuto, a professor of anthropology at Tulane University, who was also part of the research team.

Researchers have always assumed that Mayan cities were not dense. But the new LIDAR data suggests that they developed huge populations in urban settings similar to the early metropolises of China and Rome. A complex, humming urban landscape is “no longer seen as impossible for the Maya,” Estrada-Belli said.

The team mapped a total of 810 square miles (not all of which was contiguous). It paints an entirely different picture of the way Mayans used their land. One could say that Mayans were extreme geoengineers—they drained wetlands and built terraces on hillsides and dug irrigation channels almost everywhere.

“They were not only good mathematicians and astronomers, but they were also very good engineers of their environment,” Estrada-Belli said. “Everything was done with a purpose, and every inch of the ground has been manipulated in some form. The amount of investment is unprecedented.”

And that, maybe more so than the knowledge of the Mayan civilization’s scale, could be a radical shift in our sense of history. Through these techniques, the Maya were able to preserve soils and control the flow of water in a way that maintained the soil’s richness. They withstood droughts and other natural disasters as a result. Could it be that we might rule out climate disaster as the culprit in Mayan cities’ mysterious decline?

“We’re going to have to rethink our ideas about how they were not good stewards of the environment and therefore they might have caused their own collapse,” Estrada-Belli said.

Canuto says all civilizations share one trait: that they eventually decline and crumble. What we could be seeing in this new data, then, are lessons—evidence of infrastructural blunders, say. “Perhaps all of this manipulation and intensification was in an attempt to extend, expand, and maintain something that was, in the long-term, not sustainable,” Canuto said.

Estrada-Belli noted one theory that hasn’t received much traction, but which could become more plausible with this new data: These robust changes in the northern part of Mayan territory—trade routes, canals, and so on—may have starved the southern cities of resources. Ultimately, they were the first to die.

“It could have made the south irrelevant,” he said.

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Last year, I created a Twitter thread of 28 black scientists who made contributions to a variety of scientific disciplines—from designing the first moon-based space observatory to creating treatments for leprosy. There were common themes in many of their stories. Many of the scientists were barred from attending top university and research institutions, forced to take entry-level jobs despite their education and experience, and many died without their contributions to science being fully acknowledged and celebrated.

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