Decade-Long Search Uncovers Highest Known Ice-Age Human Settlements

One of the sites, the Cuncaicha rock shelter Kurt Rademaker

Archaeologists have stumbled upon two sites in the Peruvian Andes that are, to date, the highest Ice Age human settlements ever discovered. The sites, in what is now southern Peru, served as shelters and at least temporary homes for people as long as 12,800 years ago, according to a study describing the findings published today in the journal Science.

The higher of the two sites sits 14,700 feet above sea level. That's nearly 3,300 feet higher than the previous record-holding find, in northwest Argentina, says study co-author Kurt Rademaker, an archaeologist at the University of Tübingen in Germany.

The findings challenge previously held beliefs about how long it must have taken humans to evolve and adapt to living at such lofty altitudes; the study suggests people moved to these high-elevation sites 2,000 years after first arriving in South America.

"For humans to have evolved high-altitude traits in 2,000 years—that's really fast," Rademaker told Newsweek. "I'm not saying it's impossible, but it would be telling us something new about human evolution."

Regardless, though, "It tells us that people were capable of more than we thought, earlier than we thought," he adds.

The researchers carefully analyzed more than two dozen rock tools found at the two sites, including projectile points and scrapers fashioned from obsidian, a type of volcanic, glass-like rock.

Coropuna, the highest volcano in Peru, is found near the ancient settlements. Kurt Rademaker

The impetus for the exploration came from an unlikely place: a Paleo-Indian fishing site on the Pacific Coast of modern-day Peru, about 90 miles away. Here, back in the 1990s, scientists found obsidian materials that couldn't have ended up there through any geologic process. They must have been carried there by humans, researchers thought.

So, Rademaker reasoned, there must be signs of past human activity or settlement wherever this particular type of obsidian came from. Rademaker went about mapping the areas in the mountains where this type of rock is found, and he spent years looking for the sites, beginning nearly a decade ago.

At the mountain sites, the researchers found tools, bones from hunted animals, ceramics and other evidence of human dwelling. They also found the remains of starchy plants and tubers likely taken there from lower elevations to eat (they likely couldn't grow there naturally, Rademaker says). Bone analysis suggests the area's dwellers hunted llama-like animals called vicuña and guanaco, as well as deer-like creatures called tarucas. The former animals are similar to alpaca, which tastes "delicious," he adds. "Like deer, but less gamey." (Andean residents commonly eat alpaca.)

The study makes it clear these ancient people were "settled in there, it wasn't like they were just exploring," says Mike Waters, a geoarcheologist at Texas A&M University who wasn't involved in the research.

But why live in such a high place, where the solar radiation is strong and there is less than 60 percent of the oxygen found at sea level?

There may be several reasons. In this mountainous location there would have been water, animals, some plants, and shelter, Rademaker says. Nearby locations, such as the northern reaches of the Atacama Desert, would have been even less hospitable, with very little water.

Also, the idea that conditions here would be so "extreme" as to defy settlement is a modern, Western idea. "For me, a mountain lover, it's inconceivable to think that people wouldn't have popped on up there to avail themselves of the unique resources in that environment at the first opportunity," says Bonnie Pitblado, an anthropologist at the University of Oklahoma, who wasn't involved in the study.

"Mountains are special places, and it seems to me that mountains have spiritual—or in some way special—significance to virtually all people who behold them. I predict that as Kurt and his team continue to work in the Andes, they'll find more sites" like these, she says.