What stood out most to researchers was not just that people traveled more than 400 miles (700 kilometres) along Peru’s coast centuries before the rise of the Inca Empire. It was that many of them appear to have carried their identities and traditions with them.
One woman buried in Peru’s Chincha Valley had traces of red pigment on her cheek centuries after her death. Beside her lay spinning tools wrapped with yarn and cotton. Her pelvic bones also showed signs that she had likely given birth.
For Jordan Dalton, co-lead author of the study published in Nature Communications, details like this are what made the research feel more human.
“It was interesting to think about how the very powerful and personal experience of giving birth can be inscribed in bones,” Dalton told Discover. “The burial items were not merely tools that had been included, but rather they symbolized the act and conveyed who this individual was while living.”
By combining ancient DNA with archaeological evidence, researchers found that migrants from Peru’s north coast had reached the Chincha Valley by at least the 13th century, nearly 800 years ago, and centuries earlier than many researchers once believed coastal migration began.
The communities settled in the region, intermarried with local populations, and preserved distinctive cultural traditions.
Ancient DNA Reveals Pre-Inca Migration Along Peru’s Coast
The research team analyzed DNA from 21 individuals buried in Peru’s Chincha Valley to trace family relationships.
Members of the Proyecto de Investigación Arqueológica Las Huacas bring out the excavation equipment to Complex N1 at Las Huacas.
(Image Courtesy of Jordan Dalton)
The earliest migrants remained separate from local populations at first. Later generations carried ancestry from Peru’s northern, central, and southern coasts as communities gradually intermarried over time.
Some of those connections remained visible for at least 200 years.
“The preserved burial traditions show enduring practices and a strong local identity. This does not mean that it was a stagnant identity, but that there was on some level an idea of a shared culture that encompassed burial practices and material culture,” Dalton shared with Discover.
The team also identified a grave of close relatives, suggesting some families may have practiced marriage within the group to retain resources and social ties.
Read More: Potatoes May Have Given Some Andean Populations a Genetic Advantage 6,000 to 10,000 Years Ago
Burial Traditions Showed Who Belonged
Some individuals were buried in large above-ground tombs called chullpas, while others were placed in smaller stone-lined graves beneath the ground. Some also showed signs of cranial modification, in which the skull was reshaped during infancy.
Red pigment made from ochre or cinnabar appeared unevenly throughout the burial sites. Individuals painted with the pigment were found primarily inside the larger chullpas, and even there, not everyone received the same treatment.
“To me, this suggests that communities were expressing differences in status or group membership through their burial practices,” co-lead author Jacob Bongers told Discover. “Boundaries between ‘us’ and ‘them’ were being delineated through these burial practices, which brings up a famous line in archaeology: the dead do not bury themselves.”
Room A2 in Complex N1 after excavators recovered the first prepared floor, between the two walls in the hallway is where the family ossuary was located.
(Image Courtesy of Jordan Dalton)
Why Ancient Coastal Migration Went Undetected for So Long
Long-distance migration remained difficult to detect, partly because archaeologists were asking different questions.
Much of Andean research focused on movement between environments, such as the coast and highlands, rather than movement within the coastline itself. Researchers also relied on isotopic techniques, which can identify broad origins but struggle to trace movement between neighboring coastal communities.
“Our research is innovative because it combines ancient DNA (aDNA), archaeology, and colonial-era written sources to track the movement of peoples along Peru’s coast,” Bongers shared with Discover.
Bongers said the work also served as a reminder that the individuals behind the DNA samples were real people with lives that rarely appear in historical records.
“These individuals have always felt human to me. This is because every individual carries an untold story and life history that are largely not discussed in the colonial-era records,” he told Discover.
Read More: 5,000-Year-Old Ancient Noblewoman Remains Found at Site Unfit for a Queen
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
- This article references information from a study published in Nature Communications: Ancient DNA reveals a family ossuary and long-distance migration on the Pacific coast before the Inca Empire
