Media release
From: Springer NatureThe decline of the ancient inhabitants of Rapa Nui was unlikely to have been caused by a self-inflicted population collapse, a Nature paper suggests, thereby rejecting a contentious theory of ‘ecological suicide’. The findings shed light on the population history of the island.
Rapa Nui (formerly known as Easter Island) is one of the most remote inhabited places in the world, around 3,700 km west of South America and over 1,900 km east of the closest inhabited island. Two key features of the island’s demographic history have been a point of contention: whether the population of Rapa Nui collapsed after overexploiting local resources in the 17th century (prior to the arrival of Peruvian slave raiders in the 1860s and Europeans in 1722), and whether there was trans-Pacific contact between the Rapanui (the inhabitants of Rapa Nui) and Native Americans.
Working in close collaboration with the current Rapanui community, J. Victor Moreno-Mayar, Anna-Sapfo Malaspinas and colleagues studied the genomes of 15 ancient residents, who lived on the island during the past 500 years. The authors find no evidence of a genetic bottleneck that would correspond to a collapse in the 17th century. Their analysis instead suggests that the island was home to a small population that steadily increased in size until the 1860s, when Peruvian slave raids forcibly removed a third of the island’s population.
In addition, the analyses indicate that — similar to present-day Rapanui individuals — the ancient islanders harboured Native American DNA. They calculate that this mixing is likely to have happened somewhere between 1250 and 1430 CE. Taken alongside archaeological evidence and oral histories, this finding suggests that Polynesians may have been crossing the Pacific well before Europeans arrived in Rapa Nui and well before Columbus arrived in the Americas.
These genomic data will now be used to help to identify and repatriate some of these lost ancestral remains. The paper tells a story not only about resilience in past populations, but also sensitivity in research.
Expert Reaction
These comments have been collated by the Science Media Centre to provide a variety of expert perspectives on this issue. Feel free to use these quotes in your stories. Views expressed are the personal opinions of the experts named. They do not represent the views of the SMC or any other organisation unless specifically stated.
Dr Lisa Matisoo-Smith, Professor of Biological Anthropology, University of Otago, comments:
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: