Ice age Andes settlement found at record high altitude 12,400-year-old site

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Ice age Andes settlement found at record high altitude
12,400-year-old site in Peru shows ice age humans more adaptable than thought

By Emily Chung, CBC News Posted: Oct 23, 2014 2:00 PM ET Last Updated: Oct 23, 2014 2:00 PM ET
The harsh environment of the Andes settlement made it a challenging project for the international research team, who braved freezing temperatures, headaches and exhaustion from low oxygen and rugged camping conditions to complete their work.

The harsh environment of the Andes settlement made it a challenging project for the international research team, who braved freezing temperatures, headaches and exhaustion from low oxygen and rugged camping conditions to complete their work. (Matthew Koehler)
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    Summary of paper in Science

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Archeologists have found an ice age settlement so high in the Peruvian Andes that they were surprised ancient humans could survive the low oxygen there.

The 12,400-year-old settlement was found in a cave called the Cuncaicha rock shelter, located nearly 4,500 metres above sea level. That makes it the highest ice age human settlement ever found.
Kurt Rademaker and Sonia Zarrillo

Kurt Rademaker of the University of Maine and Sonia Zarrillo of the University of Calgary were part of an international team that excavated a 12,400-year-old human settlement found nearly 4,500 metres above sea level. (Walter Beckwith)

The site is more than 2,000 metres higher than the famous Inca archeological site Machu Picchu — where travellers already risk becoming ill from altitude sickness — and just 880 metres lower than the Mount Everest base camp in the Himalayas.

The discovery, published online Thursday in the journal Science, suggests that just 2,000 years after arriving in South America, humans had already spread into some extreme environments.

"High altitude was not a barrier to human colonization at least by 12,400 years ago," said Sonia Zarrillo, an adjunct assistant professor of archeology at the University of Calgary, who co-authored a study describing the discovery.

    Summary of paper in Science

The harsh environment made it a challenging project for the international research team, who braved headaches and exhaustion from low oxygen, freezing temperatures and rugged camping conditions to complete their work.
Cunchaica rock shelter

The Cuncaicha cave shelter was big enough to fit 20 or 30 people and had been occupied multiple times over thousands of years. (Kurt Rademaker/University of Maine)

"This was the hardest archeology I've ever done," Zarrillo said.

Kurt Rademaker, lead author of the study, stumbled upon the Cuncaicha cave while looking for a place to camp for the night during research for his PhD thesis a few years ago. Rademaker "instantly recognized that it was an archeological site," Zarrillo added.

At the time, Rademaker, now a visiting assistant professor of anthropology at the University of Maine, was trying to find out where a mineral called obsidian found at archeological sites on the Peruvian coast may have come from.

Excavations at the Cuncaicha rock shelter, which was big enough to fit 20 or 30 people, revealed that it had been occupied multiple times over thousands of years.
Family groups

So far, the artifacts recovered include scrapers, tools used to process animal hides so they could be used to make things like clothing and tents. Zarrillo said that is good evidence that people stayed at the settlement for long periods of time.
Kurt Rademaker

Kurt Rademaker, lead author of the study, stumbled upon the Cuncaicha cave while looking for a place to camp for the night during research for his PhD thesis a few years ago. (Walter Beckwith)

"We do tend to think that this was family groups that were there, not just men going up hunting and bringing meat back."

She added that the soot-blackened walls of the cave suggest that campfires burned inside for long periods of time, and there was lots of charcoal and bones from llama-like vicunas and guanacos at the site: "They were sure eating a lot of meat."

The cave is located in a cold and dry area of the Andes that Zarrillo describes as "a moonscape."

"Today if you just saw a picture of the site, you would say, 'Who the heck would want to come up here and why?'"

But the nearby Pucuncho Basin appears to have been a rich, moist hunting ground for animals such as vicunas and guanacos 12,000 years ago, when the climate was just a little bit cooler and wetter.
Genetic adaptation?

Today, the area is used by local Andean herders to graze thousands of llamas and alpacas. The locals have genetic adaptations that allow them to live comfortably at high altitude, such as unusually large lung capacities, high metabolic rates and the ability to carry more oxygen in their blood. Those adaptations were thought to have taken thousands of years to evolve.

The fact that humans were living at these altitudes for long periods of time just 2,000 years after entering South America raises scientific questions.

"Other people have suggested that people could not and did not live at those elevations prior to genetic adaptations occurring," Zarrillo said. "What we're showing is either they were genetically adapted to living up there or it didn't matter."

Zarrillo specializes in identifying edible plants at archeological sites. There are no edible plants growing in the area surrounding the Cuncaicha cave. Nevertheless, Zarrillo found bits of edible roots and tubers from lower elevations. That suggests the Cuncaicha cave dwellers were either trading with other groups or moving to lower elevations at some times of the year.

In the future, the researchers want to learn more about how the ancient cave dwellers interacted with people at other altitudes.

They also hope to be able obtain human remains with DNA from the cave that can be tested for signs of genetic adaptation to high altitude.

In addition, Zarrillo said, it's possible that there are even older settlements in deeper layers of the cave floor or other sites in the area.

http://www.cbc.ca/news/technology/ice-age-andes-settlement-found-at-record-high-altitude-1.2810407

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The harsh environment of the Andes settlement made it a challenging project for the international research team, who braved freezing temperatures, headaches and exhaustion from low oxygen and rugged camping conditions to complete their work. (Matthew Koehler)

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Kurt Rademaker of the University of Maine and Sonia Zarrillo of the University of Calgary were part of an international team that excavated a 12,400-year-old human settlement found nearly 4,500 metres above sea level. (Walter Beckwith)

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The Cuncaicha cave shelter was big enough to fit 20 or 30 people and had been occupied multiple times over thousands of years. (Kurt Rademaker/University of Maine)

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Kurt Rademaker, lead author of the study, stumbled upon the Cuncaicha cave while looking for a place to camp for the night during research for his PhD thesis a few years ago. (Walter Beckwith)

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The Pucuncho Basin appears to have been a rich, moist hunting ground for animals such as vicunas 12,000 years ago, when the climate was cooler and wetter. It is still used by local herders to graze their animals today. (Kurt Rademaker/University of Maine)

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Archaeologists Discover Highest Altitude Ice Age Human Occupation Site

Thu, Oct 23, 2014

Humans inhabited high altitudes nearly a millennium earlier than previously thought.
Archaeologists Discover Highest Altitude Ice Age Human Occupation Site

At two sites high in the southern Peruvian Andes, scientists have discovered remains that suggest human settlement about 12,000 years ago. At more than 4,000 meters above sea level (masl), they are now the highest sites for continuous human occupation ever recorded, predating the earliest known settlements by almost 900 years.

Led by Kurt Rademaker, a University of Maine visiting assistant professor in anthropology, the team investigated one site at 4,355 masl that yielded 260 stone tools such as projectile points, nondiagnostic bifaces and unifacial scrapers, which they dated to as much as 12,800 years old. The other site, the Cuncaicha rockshelter at 4,480 masl, contained lithic tools made from locally available obsidian, andesite and jasper, as well as plant remains, bones of vicuña and guanaco camelids and the taruca deer. The site also featured sooted ceilings and rock art, indicating that it was likely a base camp. It had a "robust, well-preserved and well-dated occupation sequence" up to 12,400 years old.

"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," says archaeologist Sonia Zarrillo of the University of Calgary, a key member of the research team. "There were possibly even families living at these sites, because we've found evidence of a whole range of activities." This is a significant finding that lends important clues, because previous archaeological and anthropological studies have indicated that "hunters passing through an area will take the meat back to campsites and leave the carcass in the field," adds Zarrillo. "In Cuncaicha we found remains representing whole animals, indicating they were living close to where the animals were killed. And the types of stone tools we've found are not only hunting tools but also scraping tools used for processing hides to make things like clothing, bags or blankets."

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peruarticlepic3Nevado Coropuna, the highland area of the sites. Courtesy Kurt Rademaker

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peruarticle5Cuncaicha Rock Shelter. Courtesy Kurt Rademaker

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peruarticle4Excavations at Cuncaicha Rock Shelter. Courtesy Kurt Rademaker

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But the biggest takeaway from the sites has to do with their remote, high altitude locations, the physiology of humans, and the date ranges of the remains recovered. A widely held theory suggests that humans must adapt genetically to high altitudes before they can sustain their presence there as permanent living environments. Given the commonly accepted theory that people first entered the Americas around 14-15,000 years ago, the age of the site archaeological remains suggests a relatively rapid genetic adaptation. The Andeans of today have genetically adapted to their high altitude environment, Zarrillo notes. The key differences between the Andeans and most other Native Americans in this regard include a higher metabolic rate, larger lung capacity and higher hemoglobin concentrations than the former. These adaptations have allowed them to overcome a lack of oxygen.

"Was this adaptation present 12,400 years ago? We don't know for certain," says Zarrillo. "What we're demonstrating is that these people either already developed that adaptation, or, it was possible for them to live in these altitudes for extended periods of time regardless."

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peruarticle6University of Calgary archaeologist Sonia Zarrillo uses ground penetrating radar at a Peruvian rock shelter. She is accompanied by Peter Leach, one of her co-authors for the paper published in the October 24th edition of the academic journal Science. Courtesy Walter Beckwith

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Finding the anwers to these questions will be among the objectives of future research.

Write the researchers in the report, "the Pucuncho Basin sites suggest that Pleistocene humans lived successfully at extreme high altitude, initiating organismal selection, developmental functional adaptations and lasting biogeographic expansion in the Andes. As new studies identify potential genetic signatures of high-altitude adaptation in modern Andean populations, comparative genomic, physiologic and archaeological research will be needed to understand when and how these adaptations evolved."*

The detailed study report is published in the journal Science.

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peruarticle7aKurt Rademaker (University of Maine, University of Tubingen), who led the expedition high in the Peruvian Andes. Courtesy Walter Beckwith

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*"Paleoindian settlement of the high-altitude Peruvian Andes," by K. Rademaker; G.R.M. Bromley; D.H. Sandweiss at University of Maine in Orono, ME; G. Hodgins at University of Arizona in Tucson, AZ; K. Moore at University of Pennsylvania in Philadelphia, PA; S. Zarrillo at University of Calgary in Calgary, BC, Canada; C. Miller at University of Tübingen in Tübingen, Germany; P. Leach at University of Connecticut in Storrs, CT; D.A. Reid at University of Illinois-Chicago in Chicago, IL; W.Y. Álvarez. Published in the journal Science. http://www.sciencemag.org/lookup/doi/10.1126/science.1258260

Source: Adapted and edited from press releases of the University of Maine and the University of Calgary.

http://popular-archaeology.com/issue/fall-09012014/article/archaeologists-discover-highest-altitude-ice-age-human-occupation-site

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Nevado Coropuna, the highland area of the sites. Courtesy Kurt Rademaker

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Cuncaicha Rock Shelter. Courtesy Kurt Rademaker

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Excavations at Cuncaicha Rock Shelter. Courtesy Kurt Rademaker

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University of Calgary archaeologist Sonia Zarrillo uses ground penetrating radar at a Peruvian rock shelter. She is accompanied by Peter Leach, one of her co-authors for the paper published in the October 24th edition of the academic journal Science. Courtesy Walter Beckwith

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Kurt Rademaker (University of Maine, University of Tubingen), who led the expedition high in the Peruvian Andes. Courtesy Walter Beckwi

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Highest Stone Age Campsite Reveals Grit of First Americans
South America's early migrants reached a remote oasis more than 14,000 feet high



Vicuñas graze in the Pucuncho Basin, where they may have been hunted by Paleo-Indians as early as 12,800 years ago.

Photograph by Kurt Rademaker

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Paleo-Indian hunters ventured high into the Andes Mountains as early as 12,800 years ago, as much as two thousand years sooner than previously thought.
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The finding, reported Thursday in the journal Science, suggests that South America's first inhabitants raced across the continent rather than spreading slowly to its remotest corners.

"It was a land rush, a free-for-all," said study author Kurt Rademaker, an archaeologist at the University of Tubingen in Germany. "People were much more capable and adaptable than we ever thought." (Related: "Ancient South Americans Ate Pachyderms.")

Rademaker discovered evidence of their pioneering abilities high in the arid Peruvian Andes, in a place known today as the Pucuncho Basin. With plenty of water, grass, and vicuñas (a relative of the llama), "it was an oasis in a desert region," he said.
South America Paleo-sites with arrows indicating probably coastal migration routes
Martin Gamache, NG Staff; Amanda Hobbs
Source : Michael Waters, Texas A&M University

While exploring this alpine oasis, Rademaker found an ancient campsite in a rock alcove, as well as two obsidian quarry sites. A type of volcanic glass, obsidian has long been prized for making sharp-edged tools. It's still used today for surgical scalpels.

Excavation of the sites yielded numerous stone tools, including two "fishtail" arrowheads distinctive to South America's first peoples. Radiocarbon dating of charcoal and animal bones indicated that Paleo-Indian hunters had been using the site as a base camp as early as 12,800 years ago.

Vicuñas and llamas, rather than obsidian, likely attracted hunters to the higher altitudes of the Andes, Rademaker said. Even today, people herd llamas across the 51 square mile (132 square kilometers) Pucuncho Basin.

Most likely the ancient hunters traveled seasonally to the base camp, staying there from March through November while they hunted llamas and deer.

High Living

Rademaker's research, supported in part by the National Geographic Society Waitt Grants Program, overturns conventional wisdom that prehistoric people needed long periods of time to genetically adapt to the challenges of living at high altitudes, especially the thin air. Oxygen pressure at the Pucuncho Basin is only 60 percent of its strength at sea level. (Climbers who venture there today spend time acclimatizing.)

"These are some of the highest known examples of human occupation," says anthropologist Tom Dillehay of Vanderbilt University in Nashville, Tennessee. "But it is not a great surprise, because we find people expanded widely wherever we look across South America." (Related: "7 Great Innovators in Archaeology.")

Dillehay points to evidence of ancient human occupation everywhere from Monte Verde in southern Chile (dated to 14,500 to 14,250 years ago) to Quebrada Jaguay on the Peruvian coast. (Related: "Earliest Known American Settlers Harvested Seaweed.")

These and other sites are changing our understanding of when and how quickly humans first populated South America, says archaeologist Claudio Javier Patané Aráoz of Argentina's Universidad Nacional de Córdoba.

"It can be argued strongly that these human groups arrived in the final Pleistocene times, moving and occupying different environments quickly," he noted in an email.

Geologists have shown that the basin was clear of Ice Age glaciers by 15,000 years ago. "Once the ice receded, the grass grew and the animals followed," Dillehay says. "Followed by the hunters, I'm sure."

Follow Dan Vergano on Twitter.
http://news.nationalgeographic.com/news/2014/10/141023-paleo-indians-migration-pucuncho-basin-andes-south-america-archaeology/