The people of Rapa Nui, also known as Easter Island, interbred with Native Americans before Europeans arrived, despite the 3,700 kilometers (2,300 miles) between them, ancient DNA suggests. The islanders, once the poster child for a people who brought about environmental disaster through overexploitation of resources, also appear innocent of that charge, according to the same study.
Rapa Nui is so incredibly remote that even finding it is considered one of humanity’s most remarkable achievements before the acquisition of technology such as compasses and large vessels. The civilization built there by the indigenous people became famous for the enormous sculpted monoliths they built, but it has fascinated anthropologists for other reasons.
One possibility is that the inhabitants sailed further and reached South America. On the one hand, it is much harder to miss a continent than a small island, but on the other hand, this would have required a voyage almost twice as long as that of the Polynesian islands from which the Rapanui came.
Genetic testing of the modern population of Rapa Nui has shown a diverse ancestry, but that has been skewed by the Europeans who first visited the island in 1722 and subsequently kidnapped most of the population as slaves. Now, however, DNA has been found from 15 people who lived on the island, in some cases as early as 1670, and whose remains are preserved in the Musée de l’Homme in Paris.
The possibility of exchange between Polynesia and America via Rapa Nui is highly controversial, but the presence of foods such as sweet potato, originally from South America, is difficult to explain in any other way. It also seems that the first South American chickens were Polynesian breeds.
The new study shows that about 10 percent of the ancestors of the pre-European contact Rapanui were Native American. That means that some of the population not only sailed all the way to South America, but also made their way back to their tiny speck in the vast Pacific Ocean, taking with them people they had visited. Not surprisingly, the genetic heritage of the Native Americans is most similar to that of people from coastal Chile and Peru.
No ecocide
A better-known controversy about Rapa Nui concerns the idea that deforestation of the island caused a collapse in food production, leading to famine and war. The idea was popularized by Jared Diamond in his book Collapsebut he did not come up with it. Many scientists had proposed it before Diamond based on estimates of a peak population of 15,000 and European reports of 1,500-3,000 when Europeans visited.
Others, however, have cast doubt on the story. “While it is clear that the Rapa Nui environment has been affected by human activities, such as deforestation, we did not know whether and how these changes led to a population collapse,” study author Anna-Sapfo Malaspinas of the University of Lausanne said in a statement. Diamond’s book has been held up as an example of how a well-written account of one side of a live scientific debate can capture the public imagination and become accepted wisdom among those without specialist expertise.
The DNA suggests something quite different. Population crashes lead to inbreeding. However, Bárbara Sousa da Mota said, “Our genetic analysis shows a stable growing population from the 13th century until European contact in the 18th century. This stability is crucial because it directly contradicts the idea of a dramatic population crash before contact.”
This finding is consistent with a recent study that undermines the claim that a large population was needed to build so many monoliths.
How the population was able to feed itself after they had cleared the island of most of its trees is not clear. Perhaps the crops brought back from South America by adventurers helped.
However, one part of the collapse theory seems to be confirmed by the new research. The genetics suggest that interbreeding occurred between 1250 and 1430. That means that voyages occurred not long after the Polynesians reached the island, and that they were ahead of Columbus on their way to the Americas. However, the reason that contact stopped is likely because the Rapanui, having cut down most of the palm trees, could not build boats that could make such long voyages.
The scientific debate about ecological collapse has also become highly politicized. The alleged collapse has been used as a warning of the fate that could befall the entire planet if we cut down the forests, but others see it differently.
“I personally believe that the idea of ecocide was constructed as part of a colonial narrative. That is the idea that these supposedly primitive people could not manage their culture or resources, and that they were almost destroyed. But the genetic evidence shows the opposite,” said study author Dr. Victor Moreno-Mayar of the University of Copenhagen.
In keeping with a more respectful approach to Rapanui culture, the authors of this study met with the surviving community to seek permission to test the museum specimens and define the questions to be studied. Evidence that the specimens are closely related to modern inhabitants of the island will be used to build a case for bringing the remains home.
The research was published in Nature.