Remnants of Permanent Early Human Settlements Found in the Andes

A team that included University of Wyoming researchers has used four different scientific approaches to give substantial support to the belief that humans lived in the Andean highlands of South America all year round more than 7,000 years ago.

The scientists examined human remains and other archaeological findings obtained from a site at close to 12,500 feet above sea level in Peru and demonstrated that fearless hunter gathering parties consisting of men, women and children, were able to to survive at high elevation before the beginning of agriculture, in spite of frigid temperatures, the lack of oxygen and being exposed to the elements.

Randy Haas, a postdoctoral research associate in the University of Wyoming’s Department of Anthropology led the team.

According to Haas, this provides a very strong baseline to that will help researchers understand the rates of genetic and cultural change in the Andean highlands. This region is known for the domestication of potatoes, alpaca and other plants, the emergence of state level economic and political complexity, and the fast human adaptation to life at high elevations.

The second author, Ioana Stefenescu, is a graduate student in UW’s Department of Geology and Geophysics and she worked with Haas on the research. Other contributors to the paper include Mark Clementz, associate professor in the Department of Geology and Geophysics, Alexander Garcia-Putnam, doctoral student in the UW Department of Anthropology, Melissa Murphy, associate professor in the Department of Anthropology and other researchers from the University of California-Merced, the University of Arizona, the University of California-Davis and other Peruvian institutions.

Haas led the excavations at the site in the south of Peru that uncovered the remains of 16 people and more than 80,000 artifacts, dating back to as early as 8,000 years ago. Evidence from this specific site, as well as a number of others, have some researchers estimating that hunter gatherers started living in the Andes about 9,000 years ago. The debate on whether that human presence was seasonal or permanent is however still ongoing.

The team led by Haas used four different approaches to determine whether there was early permanent use of the region:

1. Travel distances from the site to low elevation zones;
2. Studying the human bones for carbon and oxygen isotopes;
3. The types of tools and other materials found with them;
4. The demographic mixture of the human remains.

The scientists found that:

1. Travel distances to low elevation zones were too big for seasonal human migration;
2. High carbon and low oxygen isotope values were found in the bones, revealing the distinct signature of permanent high elevation occupation;
3. Almost all of the tools used by the hunter gatherers were manufactured from high elevation stone material and not brought from elsewhere;
4. The presence of women and small children meant that such migration was highly unlikely.

Haas noted that the results present the strongest evidence to date that people lived in the Andean highlands all year round at least 7,000 years ago. Such high elevation environments were among the last boundaries of human colonization and this knowledge holds implications for understanding rates of physiological, genetic and cultural adaption of humans.

The research was published in the Royal Society Open Science’s July issue. This publication is a peer reviewed, open access scientific journal.