Analysis of tools rewrites the history of Easter Island

tools on a table

Examples of obsidian tools similar to those studied by the researchers. Picture from the museum on Easter Island.

Easter Island was in contact with both Polynesia and South America as early as 800 years ago. This is demonstrated by research conducted in collaboration between Professor Helene Martinsson-Wallin of Uppsala University and colleagues in Chile. The research was presented in the prominent journal PlosOne in March 2024.

Helene with a pink flower behind her ear and statue in the bakground.

Helene Martinsson Wallin, professor of archaeology, on Easter Island.

During the archaeological excavations of the oldest settlement known to date on Easter Island in 1987–88, Helene Martinsson-Wallin found tools made of obsidian (volcanic glass). They have now been analysed in detail, using a microscope.

The researchers found traces of starch grains on the tools, which are around 800 years old, and compared these traces with a reference library of starch grains from different cultivated plants. It turned out that the tools had been used to process plants of both Polynesian origin (such as taro and breadfruit) and South American origin (sweet potato and manioc).

Confirms previous theories

The new analyses of the tools, along with genetic research published in 2024, confirms the theories Martinsson-Wallin presented in her doctoral thesis in 1994.

She argues that Easter Island was settled by people of Polynesian origin who early established contact with South America. These contacts influenced the culture and paved the way for the fashioning of the large statues on Easter Island with their singular cultural expression.

“Many other researchers have insisted that Easter Island was only colonised once, by a Polynesian people coming from the west. One exception was the well-known ethnographer Thor Heyerdahl, who argued that the island was first colonised by people of South American origin, who raised the statues, with people from Polynesia reaching the island later,” Martinsson-Wallin explains.

The new research findings now demonstrate that her theory from 1994 about the earliest history of Easter Island is the most likely.

“Naturally, it feels good to have my theories confirmed by new research. I had been hoping that my ideas could be verified by new methods such as DNA analysis,” Martinsson-Wallin says.

Extensive cultural contacts

In geographical terms, Easter Island is the most isolated place on Earth. The question of how and when the island was settled has been discussed for hundreds of years and especially intensively following Heyerdahl’s archaeological investigations there in the 1950s.

The issue of colonisation and cultural contacts between Polynesians and indigenous peoples in South America has long been a key feature of archaeological research on the Pacific islands, colonisation and the origins of Easter Island’s specific megalithic culture.

“Our research now indicates more extensive cultural contacts across the seas in prehistoric times than many other researchers have previously claimed was possible, given the seafaring craft and navigation of that time. Easter Island’s peculiar and fascinating culture arose at the intersection of these cultural contacts,” Martinsson-Wallin concludes.

Annica Hulth


Ref: Berenguer, P., Clavero, C., Saldarriaga-Córdoba, M., Rivera-Hutinel, A., Seelenfreund, D., Helene Martinsson Wallin., Castañeda, P., & Seelenfreund, A. (2024). Identification of breadfruit (Artocarpus altilis) and South American crops introduced during early settlement of Rapa Nui (Easter Island), as revealed through starch analysis. PLOS ONE, 19(3), e0298896.

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