A groundbreaking study, published in Science Advances, has used ancient DNA to shed light on the origins of workers buried more than 500 years ago within the Inca Empire, particularly at the renowned site of Machu Picchu.

Tulane archaeologist, Jason Nesbitt. Credit: Jason Nesbitt, Tulane University School of Liberal Arts

Led by Jason Nesbitt, an ᴀssociate professor of archaeology at Tulane University School of Liberal Arts, the research involved genetic testing on individuals interred at Machu Picchu, providing fascinating insights into the lives and idenтιтies of its former inhabitants.

Machu Picchu, nestled in the Cusco region of Peru, was once an opulent royal estate of the Inca Empire and continues to attract countless visitors as a UNESCO World Heritage Site. Besides accommodating members of the Inca elite, the estate housed attendants and workers who resided there throughout the year.

Machu Picchu, once lost to the Western world after Spanish colonization, was rediscovered by adventurers in the early 20th century. During the Yale Peruvian Scientific Expedition in 1912, researchers documented a remarkable count of 174 individuals buried on site. These burials are often shallow graves concealed under boulders or rocky overhangs.

According to The Conversation, To uncover the origins of these individuals, the research team sequenced ancient DNA from the remains of 68 individuals, 34 from Machu Picchu, and 34 from Cusco. Carbon dating revealed that some of the individuals were buried before the rise of Pachacuti and the Inca Empire. The DNA was then compared to that of modern Indigenous peoples in the Andes, as well as ancestries from more distant South American regions.

This DNA analysis followed a similar approach to modern genetic ancestry kits, comparing the DNA of 34 individuals buried at Machu Picchu with individuals from various regions within the Inca Empire, as well as some modern genomes from South America.

The analysis unveiled that 17 individuals had ancestry from distant sources, spanning the Peruvian coast, highlands, and Amazon regions of Peru, Ecuador, and Colombia. Only seven buried individuals showed ancestry linked to Peru’s southern highlands, where Machu Picchu and Cusco are located, though their specific ties to Machu Picchu itself could not be confirmed. Moreover, 13 individuals displayed blended ancestry, some traced to regions as far away as Brazil and Paraguay.

Maps of the provenience of the sites, groups, and individuals analyzed in this study. Credit: Salazar et al., 2023, Science Advances

There was minimal shared DNA among them, indicating that they were brought to Machu Picchu as individual workers rather than as part of familial or community groups.

The study dispelled prior ᴀssumptions and verified the diverse backgrounds of these residents.

Nesbitt, discussing the findings, clarifies, “Now, of course, genetics doesn’t translate into ethnicity or anything like that, but that shows that they have distinct origins within different parts of the Inca Empire. The study does really reinforce a lot of other types of research that have been done at Machu Picchu and other Inca sites.”

The DNA analysis aligns with historical documentation and archaeological studies of the artifacts found in ᴀssociation with the burials, further solidifying the significance of the discoveries made.

More information: Lucy Salazar et al. (2023). Insights into the genetic histories and lifeways of Machu Picchu’s occupants. Sci. Adv. 9, eadg3377. DOI:10.1126/sciadv.adg3377