Evidence suggests colonization of Rapa Nui took place later than previously assumed

UH Manoa research to be featured in Science; available online now through Science Express

University of Hawaiʻi at Mānoa

HONOLULU — Recent archaeological study and analysis conducted by University of Hawaiʻi at Mānoa anthropology professor Terry Hunt suggests that the colonization of Rapa Nui (Easter Island) took place not between 400 and 800 A.D. as previously assumed by scientists, but at least 400 to 800 years later, closer to 1200 A.D.

The finding, which challenges current beliefs about the island‘s prehistoric chronology and the dramatic environmental changes that occurred on the island, is detailed in an article by Hunt and co-author Carl Lipo of California State University, Long Beach, and scheduled for publication in the journal Science. It is previewed and available online now in Science Express.

As part of a UH archaeological field school on Rapa Nui, Hunt and a team of field researchers have been excavating archaeological deposits at Anakena, Rapa Nui‘s only sand dune and the landing and settlement site of the island‘s first inhabitants. Archaeological materials found here with superb preservation include artifacts, charcoal, faunal remains, and the distinctive tubular root molds of the giant Jubaea palm, now extinct.

Hunt explains that he was skeptical when he first got radiocarbon dating results for the samples collected.

"It didn‘t fit with what everyone believed about the island‘s chronology."

This led Hunt and Lipo to reevaluate previous radiocarbon results published for Rapa Nui. In their analysis, they applied a "chronometric hygiene" approach to exclude samples known to cause problems for radiocarbon dating. For example, marine specimens can return dates hundreds of years older than what is accurate because old carbon from the sea is incorporated in the marine animals‘ bones or shells.

When all the evidence was considered, Hunt and Lipo found no evidence to support the current assumption that settlement of the island occurred earlier than about 1200 A.D. These results compare favorably to dates applied to human impact on the island‘s environment. The evidence for later settlement of Rapa Nui also fits well with the emerging picture of chronologies for Polynesia, including remote islands such as Mangareva.

A later settlement raises some interesting implications for Rapa Nui.

"Human impacts to the environment, such as deforestation, began almost immediately, at least within a century," explains Hunt. "This means that there was no period where people lived in some ideal harmony with their environment; there was no early period of ecological sustainability. Instead, people arrived and their population grew rapidly, even as forest resources declined. The short chronology calls much of the traditional story into question."

Hunt and his team are returning to Rapa Nui this summer to continue their work. They plan to investigate in more detail the chronology of statues, monuments, and other aspects of life on the island.

"There is still a lot to learn about Rapa Nui, and a lot we really don‘t know," said Hunt.

Photo credit: Photo by Jennifer Crites.