Stone tools once used by ancient humans are providing researchers with new information about how our distant ancestors may have lived during the latest Ice Age. This discovery shows human beings were living at extreme altitudes 1,000 years earlier than previously believed, according to researchers.
Paleoindians, the first human beings to cross into the Americas from Beringia, spent at least part of the year high in the Andes, manufacturing stone tools in a workshop, exposed to the sun and wind.
Cuncaicha is located above the area used for the manufacture of tools, while a second site, Pucuncho, sits beneath the workshop.
Archaeologists discovered the Ice Age artifacts 14,700 feet above sea level in the Andes mountains of South America. A pair of graduate students made the discovery after five years of scouring the mountains for evidence of ancient habitation.
Pucuncho was likely occupied by humans, starting around 12,800 years ago, about 400 years before Cuncaicha. Each site was abandoned roughly 11,500 years before our time, just as the last Ice Age was ending.
High-altitude living provides many challenges to any people who undertake life in mountain ranges. Above 8,200 feet, hypoxia (lack of oxygen) becomes a real health risk, which can even lead to death. Extreme exposure to sunlight, as well as frigid temperatures, pose additional dangers to populations living at these heights. These altitudes are also well above the tree line, making it difficult for populations to find food.
In addition to stone tools, researchers also discovered skull fragments and the remains of animals. While hunters usually strip the meat off their kill and leave the rest of the carcass in the field, entire animal remains were found at the sites, indicating the creatures were likely raised nearby.
"We don't know if people were living there year round, but we strongly suspect they were not just going there to hunt for a few days, then leaving. There were possibly even families living at these sites, because we've found evidence of a whole range of activities," Sonia Zarrillo, an archaeologist at the University of Calgary, said.
In Tibet, evidence exists that humans lived at high altitudes - between 10,800 and 11,500 feet above sea level. However, it is uncertain whether people who produced tools there lived at those altitudes permanently, or if artifacts were left behind from a temporary occupation. Although that site is older than the one discovered in Tibet, dated to around 15,000 years in the past, the site is lower than that in the Andes.
People living in the Andes Mountains today have adapted to high altitudes, but researchers are uncertain how well the ancient population may have been suited for the heights.
Discovery of the presence of ancient humans at extreme altitudes in the Andes Mountains was profiled in the journal Science.
