For several years now, specialists from across the world come together for a conference on the topic of “first migrations of the Pacific Peoples”. In November 2018, the meeting was hosted and organized on Easter Island, Rapa Nui by its Polynesian name, under the supervision of the “Mata Ki Te Rangi” Foundation, and archeologist Sonia Haoa Cardinali, the foundation’s President.
What better place than Easter Island to host this conference ? The island was in fact one of the key stages in the human colonization of the tropical Pacific, a region that is called the “Polynesian Triangle”, stretching from Hawaï in the north, to New Zealand at its southwestern corner and Easter Island in the east. It is estimated that the first Polynesians discovered Easter island between AD 800 and 1100. They continued on their southwestwards journey to New Zealand and eastwards as far as South America. The ceaseless voyaging between the different islands of the Polynesian Triangle resulted in abundant exchange, as much in terms of flora and fauna as the intermixing of the populations and traditions. During their voyages, Polynesians carried with them a host of useful plants and animals from their home islands, necessary for their survival at sea, but that would also allow them to settle the new lands they found. Archaeological excavations have revealed information about this, hidden in the deepest and oldest layers of the soil.
New evidence also comes from other more modern disciplines, like genetics. One such plant in question was discussed during the conference, the sweet potato, that is found across the greater part of the Polynesian Triangle but originates in South America. It is the Polynesians who carried this American tuber with them on their voyages, which explains its wide distribution across the Pacific (Roullier et al., 2103). Genetic data also provides new evidence from the fauna, Polynesians chickens were introduced to South America, on the coast of Chile more specifically (Storey et al., 2007). These studies show unequivocally that Polynesians explored the limits of the Eastern Pacific Ocean. It must have been a great shock for them to discover the insurmountable barrier of this unknown continent that stretched from north to south. These successive explorations marked the end of their eastern explorations, at the very edge of this immense ocean. This final discovery must have marked their imagination, as it was the final frontier of their oceanic world. Rapa Nui, the Polynesian name for Easter Island, one of the easternmost islands of the Pacific, was undoubtedly a key link for the exchanges that occurred with the Americas, it was not on the edge of the Polynesian Triangle, but rather a center for trade.
Easter Island : events on Rapa Nui Island
This 10th conference about the migration of the first people also allowed a great deal of progress to be made regarding the history of Rapa Nui. New scientific results confirm that the initial population of Easter Island has few traces of Amerindian heritage. Genetic studies of early Rapanui skeletons demonstrate that most of their genetic makeup was of Polynesian origin (Ferhen-Schmitz et al., 2017).
A small number of Amerindian genes were nevertheless found in certain Rapanui. This raises the idea that the Rapanui didn’t just bring back foodstuffs with them on their voyages to the American continent, there also seem to have been several Pre-Columbian inhabitants (Thorsby, 2012). The intermixing of the populations that occurred on Easter Island afterwards probably explains the presence of these genetic traces. Another focus of study, presented at length during this conference was « The Rapa Nui Statue Project », overseen by the archaeologist Jo Anne Van Tilburg. Excavations of the bases of several of the statues (moai) that are placed on the outer slopes of the Rano Raraku volcano have allowed a reconstruction of the formation of these moai, that were apparently set on the slopes of the volcano from the start, making this site far more than just the quarry where the statues were sculpted.
The dating of the deposits suggests that statue building ceased somewhere around AD 1580 and 1630 (Simpson et al., 2018). Lastly, the discussions and talks allowed a better understanding of the supposed ecosuicide of the Rapanui population. During the 17th century it is known that a radical change in the ancient traditions occurred, the carving of moai (and probably the associated religious cult) were abandoned. This culture shock corresponds with an equally significant environmental shift, that includes the disappearance of large areas of diverse forestland, demonstrated by studies of the different types of pollens found in lake sediments (Flenley and King, 1984) but also the types of fuels used for preparing food in ancient oven sites (Orliac and Orliac, 2001). These studies reveal that large trees rapidly disappeared during the 17th century but there were also a variety of bushes that disappeared too. For decades, certain writers have attributed the disappearance of a large part of the flora and fauna to human folly: caused by the overuse of large logs to transport the gigantic statues, leading the people of Rapanui to deforest their island.
But this supposed eco-suicidal “collapse” of Rapa Nui’s civilization was called into question and largely rejected in this 10th colloquium. Several works demonstrate the resilience of this ingenious population, with proof of continued agricultural activities after the 17th century (Mulrooney et al., 2013). A people that were so careful with their environment would not have destroyed the ecosystem themselves. Environmental changes have been detected through new approaches used by French research teams. The first study focused on reconstructing the well-known “ El Niño” or “La Niña” climate phenomena in the past. They are linked with a weakening (or strengthening) of the trade winds, a tropical wind that blows from east to west, and has important influence on the entire Pacific, and even the entire planet.
The results of this study show that there was an unusually high number of “La Niña” events (increase in the trade winds) in the Pacific at the beginning of the 17th century, that could have caused a 30% reduction in rainfall on Easter Island. This anomaly would have caused drought, and probably broadly impacted the island’s entire vegetation (Delcroix et al., 2018). This observation is paralled by a striking trend in the sediment records, analyzed using core samples made in 2017 by another scientific team, whose expedition to Easter Island was featured in a previous article in this magazine (RevaTahiti n° 78, 2018). The contents of these sediment cores show an unusually high level of soil erosion around the beginning of the 17th century, around the same time that the forests were disappearing. These results suggest that the climate was particularly arid between 1600 and 1640.
Large scale climate change across the Pacific would have reduced rainfall on the island. The trees, imported by the Polynesians were already at the limits of their climate tolerance here, and were not able to resist the drought. It may no longer be necessary to invoke human error to explain the drastic environmental changes that occurred on Easter Island: climate change is enough. The combined results presented during this 10th congress on Polynesian migration point toward new conclusions regarding Easter Islands’ history.
This island, thought to be at the eastern limit of the Polynesian triangle, appears to have played a central role in a trade network whose true limit was the coast of South America. These economic and commercial exchanges never really ceased, as demonstrated by genetic studies of the origins of ancient foodstuffs, refining our knowledge of the interactions that occurred with Amerindian populations. The eco-suicide hypothesis, that of the environmentally induced collapse of Rapa Nui’s civilization, that sometimes still circulates in the collective subconscious, has at last been definitively dismissed. It is the resilience of the Rapa Nui people that should be studied. These Polynesians succeeded in surviving in an isolated and challenging environment, and to adapt to major environmental shifts. The Polynesian culture survived and continues to evolve even to this day.
Source : Reva Tahiti Magazine
Text : Bruno Malaizé et Thierry Delcroix
Pictures : Danee Hazama, Thierry Delcroix, M. Orliac