Two recent studies challenge the theory that Easter Island’s population collapsed in the 17th century.e century following overexploitation of resources, often presented as one of the first “ecocides” in History.
Easter Island, located in the Pacific 3,700 km off the Chilean coast, is famous throughout the world for the monumental statues sculpted by the Rapanuis, the enigmatic “Moai”.
A popular hypothesis, based in particular on paleoenvironmental data, suggests that the Rapanui deforested the island, which is known to have once been covered in palm trees, in order to maintain a flourishing culture and a population of around 15,000 individuals at its peak.
The scarcity of resources would have led to a period of famine and warfare leading to cannibalism and would have ended in a demographic and cultural collapse, putting an end to the carving of statues in the early 17th century.e century.
At the time of their arrival in 1722, Europeans estimated the island’s population at only 3,000 individuals.
With the story of this “ecological suicide”, also called “ecocide”, the story of the Rapanui “has been presented as a warning against the overexploitation of resources by humanity”, recall the authors of a study published Wednesday in the journal Nature.
This international team of population genetics specialists set out to find traces of this collapse, using HapNe-LD, an advanced statistical tool that can reconstruct the demographic history of a population based on the genetic structure of current or former individuals.
They analyzed the genomes of 15 Rapanuis that lived between 1670 and 1950 and found no genetic signatures of such a collapse, such as a sudden drop in genetic diversity.
“Our genetic analysis shows a stable growing population of the 13the century until contact with Europeans in the 18th centurye century. This stability is crucial because it directly contradicts the idea of a dramatic collapse before the arrival of Europeans,” explains in a press release Bárbara Sousa da Mota, first author and researcher at the Faculty of Biology and Medicine of the University of Lausanne.
The study, carried out in close collaboration with the Rapanui community, also highlighted contacts between the island’s population and the Amerindians prior to the arrival of Christopher Columbus on the continent, another controversial point in the history of Polynesian peoples.
Stone gardens
These results corroborate those published last June in Science Advances by a team that has taken a very different approach.
The fact that these two studies reach similar conclusions “shows the importance of approaching the same scientific question from different disciplines,” Sousa da Mota told AFP.
The scientists mapped the island’s “rock gardens,” an agricultural technique that involves mixing rocks into soil to enrich it with nutrients and preserve moisture.
Using high-resolution shortwave infrared (SWIR) satellite images and developing machine learning models (machine learning) to analyze them, they were able to re-evaluate the place occupied by these stone gardens.
These agricultural areas, which were previously thought to cover between 4.3 and 21.1 km2would in fact have occupied only 0.76 km2 of 164 km2 from Easter Island.
Existing work makes it possible to calculate the yield of these lands, where sweet potatoes were cultivated, essential to the Rapanuis’ diet. And to deduce the maximum size of the population that they could feed.
These new data suggest that it could never have exceeded 4,000 people, and not 17,000 as envisaged from previous estimates.
“When we label an entire culture as an example of bad choices, or a warning about what not to do, we have to be sure we’re right, otherwise we’re feeding stereotypes, which themselves have profound consequences for populations,” Dylan Davis, a climate, biology and paleoenvironment researcher at Columbia University and co-author of the study, told AFP.
“In this case, the Rapanui managed to survive in one of the most isolated places on the planet and did so quite sustainably until contact with Europeans. This suggests that we can learn from them how to manage limited resources,” he says.