Genome Sequencing Provides Latest Evidence Against Easter Island’s Societal Collapse

Shortly after Europeans first came to the remote Pacific territory they called Easter Island, a narrative arose around the people they found there. According to the story, the people had depleted the island’s resources, which drove them into cannibalism and a severe population collapse, often referred to as ecological suicide. New analysis of DNA from some of the island’s historic residents tells a very different story.

Using radiocarbon dating and genome sequencing, a research team, which included J. Víctor Moreno-Mayar, a geneticist from the University of Copenhagen, concluded that the population of Rapa Nui, as the island is now known, never experienced such a dramatic decline. The team also found some surprising information about the ancestors of Rapa Nui’s people, which could have a major impact on our understanding of how how pre-colonization populations mixed and interacted.

Previous archaeological research had shown that Rapa Nui was first settled by Polynesian people around the year 1250 CE. Over the next five centuries, the descendents of those people developed what became known as the Rapanui culture, which is best known for the towering, stone-faced statues known as Moai (to be clear, “Rapanui” refers to the people, whereas “Rapa Nui” refers to the island).

For many years, the prevailing theory was that, as the island’s population grew, eventually reaching a peak of around 15,000, they deforested the island, leading to food shortages. That resulted in a population of just 3,000 by the time Europeans arrived. In recent years, evidence has started to mount that this wasn’t the case, including analysis of tools used by the Rapanui that indicate a thriving society in the timeframe of the supposed collapse.

The new DNA analysis, published in Nature today, adds further support to the growing counternarrative. They reconstructed the genomes using samples from 15 human remains, which radiocarbon dating suggests are from individuals who likely lived before 1860. Using that data, they were able to infer how closely the people of Rapa Nui were related across time. While there was a small reduction of population in the time period around the island’s settlement, the evidence showed gradual growth across time. There was no population explosion, the scientists wrote. Rather, there was just steady growth, from the first settlers until Europeans got there in 1722.

The findings are the latest blow to the narrative that, when Europeans first came to Rapa Nui, they “found a miserable community with only a few people remaining after overconsumption, violence and cannibalism during the seventeenth century,” wrote Stephan Schiffels and Kathrin Nägele, both from the Max Planck Institute for Evolutionary Anthropology, in an accompanying News & Views article. “The latest results join a growing amount of evidence that Rapa Nui could, in fact, sustain a large population despite environmental changes, with first historical accounts describing the island as ‘earthly paradise.’”

Schiffels and Nägele drew a comparison between the supposed collapse of Rapa Nui and humanity’s current struggle with climate change. Rather than a narrative of despair, they wrote, perhaps Rapa Nui could provide “a hopeful story about humans’ resilience and capacity to learn to manage resources sustainably in the face of environmental changes.”

Another finding presented in the new paper was just as surprising. Previous DNA analysis of ancient Rapanui remains hadn’t found any signs of Native American genetics. Using the more comprehensive whole genome sequencing, the geneticists found evidence that the Rapanui began having babies with Native Americans some time between 1336 and 1402—after their arrival on the island, and centuries before Europeans got there. In total, around 10% of the DNA could be traced to people indigenous to coastal South America.

What remains unclear is exactly how those people from the American continent got there. Rapa Nui is over 1,180 miles (1,900 kilometers) away from the nearest inhabited island, making it one of the most remote inhabited places on the face of the planet. Though technically a part of Chile, it’s 2,290 miles (3,686 kilometers) from the mainland.

One important caveat to the study is how the researchers obtained the samples. The DNA was taken from human remains that had been sent to a Paris museum in the 19th century. That kind of colonial practice is understandably disturbing and upsetting, and the anthropologists made sure to address it in their work. In the study’s text, they made it clear they worked with Rapa Nui communities to get consent to examine the human remains. In their analysis, they found the human remains were related to modern day Rapanui, a finding they wrote will hopefully lead to the samples eventually being repatriated.