New genomic research rejects a contentious theory that ancient inhabitants of Rapa Nui (Easter Island) experienced population declines due to overexploiting the island’s natural resources, known as the ‘ecocide’ theory.
A team of international researchers reconstructed the genomic history of 15 ancient Rapanui, who lived on the island in the past 500 years, finding no evidence of a genetic ‘bottleneck’ that would link to a collapse in the 1600s. Their analysis suggests Rapa Nui was home to a small population that steadily increased until Peruvian slave raids in the 1860s forcibly removed a third of the population.
They also found about 10% Native American DNA in ancient as well as present-day Rapanui, supporting the idea that Polynesians may have been crossing the Pacific to the Americas and back well before Columbus arrived in the Americas.
The researchers say their work will also support repatriation of ancestral remains currently held in a Paris museum.
The Science Media Centre asked third-party experts to comment. Feel free to use these comments in your reporting or follow up with the contact details provided.
Dr Lisa Matisoo-Smith, Professor of Biological Anthropology, University of Otago, comments:
“There is something about Easter Island/Rapa Nui that, since the time of first European contact, elicits intrigue, speculation and story-telling. How did the ancient settlers get there and from where? How could people survive in such an isolated and desolate environment? And, of course, there are the Moai. The popular work of Thor Heyerdahl’s “Kon Tiki” and, more recently, Jared Diamond’s “Collapse” has driven much of the fascination with Rapa Nui, their origins and the eventual collapse of their society. However, archaeological, linguistic and biological evidence over the last 50 years has provided answers for most of these questions. Despite this, people seem to be reluctant to let go of the emotive stories.
“We know that the original Polynesian voyagers who discovered and settled Rapa Nui at least 800 years ago were among the greatest navigators and voyagers in the
world. Their ancestors had spent at least 3000 years living in an Oceanic environment. They sailed eastwards across thousands of kilometres of open ocean and found almost all habitable islands across the vast Pacific. It would be more surprising if they had not reached the coast of South America. These results do provide some intriguing evidence of the timing of that contact.
“The whole model of ecocide and societal collapse has also been questioned by Pacific scholars, based on a range of archaeological evidence. But now, we finally
have ancient DNA evidence that directly addresses these two questions and perhaps will allow us to focus on a more realistic narrative of the history of this intriguing, yet actually rather typical, Polynesian island.
“What is particularly pleasing is that the ancient DNA research was done in consultation with and with the full support of the local community. Not that we should require scientific evidence beyond the collection records, but it is good to know that this will assist with repatriation of these tupuna to Rapa Nui.“
Conflict of interest statement: Professor Lisa Matisoo-Smith is a molecular anthropologist who works on ancient DNA of people, plants and animals to understand Pacific settlement. She has previously published with several of the authors on a different topic, but was not involved with this research.
Dr Phillip Wilcox (Ngāti Rakaipaaka, Ngāti Kahungunu ki te Wairoa, Rongomaiwahine, Te Aitanga-a-Mahaki), Associate Professor in Quantitative Genetics, Department of Mathematics and Statistics, Kaikōkiri Māori, Genetics Teaching Programme, and Affiliate of the Bioethics Centre (Te Pokapū Matatika Koiora), University of Otago, comments:
“This study demonstrates many strengths but also some limitations inherent in academic research when using modern scientific technologies to address hypothetical events and challenge contemporary views.
“On the positive side it provides strong evidence against long-held views that the native Rapanui peoples (who, like Māori, are of Eastern Polynesian origin) essentially committed ecocide, supposedly leading to population and cultural collapse. By implication this paper raises questions about the academic rigour and motivations of those that have propagated myths of ecocide without strong and compelling evidence. Perpetuation of falsehoods by Westernised academic institutions and other powerful actors has long plagued native peoples around the world, including Aotearoa.
“Dispelling such false narratives is challenging, but as shown by these researchers, the tools of modern science can play a role in providing more informed analysis. Moreover, these authors appeared to have taken a strong ethical approach to study design and conduct: they consulted with local Rapanui community to ensure the study was conducted in an appropriate manner and that the narratives written by the researchers were acceptable to indigenous Rapanui community representatives.
“They also ensured there were benefits from the study in regard to repatriating the remains of ancestors – which is important in many Eastern Polynesian as well as other cultures. As such, the research team is to be commended for their efforts to ensure the research does not perpetuate further harms to the community being studied – as has happened multiple times in the past in genetics-based investigations.
“One limitation of this study however, is that information generation appears to be based entirely on technologies of modern science, without substantive inclusion of traditional knowledge from indigenous Eastern Polynesians. There is no mention of any efforts to obtain oral histories of supposed population collapse from the Rapanui people themselves, despite widespread practices of handing down purukau (stories) over generations in Eastern Polynesian cultures.
“Moreover, I’m aware that within some oral histories are names of native American ancestors along with purukau about them and where they lived, which indicate it was Eastern Polynesian navigators that went to South and Central America, rather than vice versa. This is consistent with other opinions – for example Matisoo and Gosling (2020) and Crowe (2018) who provided strong rationale for contact between native Americans and Eastern Polynesian occurring in Central and/or South America.
“This study – along with previously published genetic sciences-based research showing evidence of native American ancestry in Polynesians – could have been strengthened by inclusion of indigenous knowledge and a more comprehensive understanding of the histories of Eastern Polynesian peoples. By ignoring such traditional knowledge, researchers and other actors such as scientific journals, unfortunately perpetuate the assumption that indigenous knowledge is of little or no value in addressing key questions about very populations they are actually studying.”
No conflicts of interest.