Easter Island, the 64-square-mile speck in the Pacific Ocean also known as Rapa Nui, was once the poster child for “ecocide.”
According to the theory, popularized by geographer and science writer Jared Diamond, the first people to reach Rapa Nui around 1200 A.D. began felling the forests that covered the island. As the supply of wood for building canoes and homes dwindled, and as they gobbled up the island's sea birds, the inhabitants split into rival clans, each of which built the moai—the striking, nearly 1,000 giant stone carvings found around the island—to outdo one another. Eventually, resources dwindled more and the whole place unraveled, leading to warfare, cannibalism and death.
Something like this, reports Sarah Sloat at Inverse, is what researcher Dale Simpson, Jr. of the University of Queensland expected to find in his new study in The Journal of Pacific Archaeology. According to a press release, he and his team took a look at 21 of the 1,600 basalt tools recovered during excavations from the period dating between 1455 and 1645, the time when Rapa Nui was supposed to be in turmoil and decline. The team wanted to know where the people carving the statues got their tools from. There are three basalt quarries on the island, and if the island was full of warring clans, they anticipated the tools would come from the quarry closest to home.
Using lasers to cut off tiny bits of the tools, they analyzed the stones using mass spectrometry, which shows distinct chemical signatures from each quarry. The results showed that almost all the tools came from the same area. “The majority of the toki [stone axes] came from one quarry complex—once the people found the quarry they liked, they stayed with it,” Simpson says in the release. “For everyone to be using one type of stone, I believe they had to collaborate. That's why they were so successful—they were working together.”
That means rather than have one clan bogarting all the best basalt, he tells Megan Gannon at LiveScience that there was likely a system of exchange between the clans and that they allowed others to cross their boundaries to collect shared resources. “I think that that goes against the collapse model that says all they were doing was competing to build bigger statues,” he says.
Co-author Jo Anne Van Tilburg from UCLA, director of the Easter Island Statue Project which found the tools, cautions that this isn’t the last word on the matter and says the tools might not hint at cooperation. “It may also have been coercive in some way,” she says. In other words, clans may have fought or raided for the tools or taken them from other groups. “Human behavior is complex. This study encourages further mapping and stone sourcing, and our excavations continue to shed new light on moai carving.”
Whatever the origin of the tools mean, there’s growing evidence against the traditional narrative of the island's collapse. Indeed, the ecocide theory has come under increasing scrutiny lately, as Catrine Jarman points out in the Conversation, with researchers finding evidence that the inhabitants actually adapted to their changing landscape and lived a sustainable existence until disease introduced by European explorers destroyed much of their population.
Another wrench in the collapse theory? Rats. As Robert Krulwich at NPR explains, stowaway Polynesian rats which were brought to the island with the first inhabitants may be the ones responsible for denuding the island of trees. With no natural predators, the rats went wild, snacking on the roots of palm trees, slowly but surely killing off the forest. Along with the trees went other plants, all the land birds and many seabirds. There was an ecological collapse, anthropologists Terry Hunt and Carl Lipo, from the University of Hawaii argue, but it wasn’t set off by greedy people. It was caused by invasive species.
And as their ecosystem and resources disappeared, evidence suggests the Rapa Nui did not devolve into chaos, warfare and cannibalism. Instead, they adapted to their new situation. Studies of the islanders’ teeth and examinations of their garbage dumps show that they were heavily reliant on the rats for food throughout their occupation of the island, as well as terrestrial foods like yams and bananas. “What archaeologists who conduct fieldwork on the island have learned in the past 20 years is that the evidence dramatically contradicts the tales that most people have heard,” as Carl Lipo, a Binghamton University anthropologist not involved in the study, tells Gannon of LiveScience.