A new perspective on the history of Easter Island’s population

A recent study challenges the traditional theory of Easter Island's ecological collapse, showing that Polynesian settlers found ingenious ways to sustain themselves through stone gardens, maintaining a stable population for centuries

Around 1,000 years ago, a small group of Polynesians crossed thousands of miles of ocean to settle on one of the world’s most remote locations: the island they named Rapa Nui, or Easter Island. Here, they built hundreds of “Moai“, the famous stone statues. The traditional story tells of a population that grew excessively, depleted natural resources, and led to the collapse of their civilization. However, a new study presents a different version.

Ingenious resource management

Recent research suggests that the population of Rapa Nui never became unsustainable. The inhabitants found ingenious ways to manage the island’s limited resources, maintaining a stable population for centuries. Evidence of this lies in the “stone gardens,” where they cultivated nutritious sweet potatoes. These gardens covered only enough area to support a few thousand people.

Challenging the ecological collapse theory

The study, published in Science Advances, challenges the theory of ecological collapse. Dylan Davis, a researcher at the Columbia Climate School and lead author of the study, stated:

“This demonstrates that the population could never have been as large as some previous estimates. The people were highly resilient in the face of limited resources, effectively modifying their environment.”

The role of stone gardens

The stone gardens, crucial for the survival of Rapa Nui’s inhabitants, are still used today by some residents. These gardens exemplify how the settlers coped with the island’s harsh environmental conditions.

Easter Island’s Challenges

Easter Island is one of the most remote inhabited places on Earth. Located 2,175 miles from Chile, its volcanic soil is less fertile compared to other tropical islands like Hawaii and Tahiti. The inhabitants had to work much harder to gather marine resources due to the deep surrounding waters.

Lithic Gardening Techniques

To tackle these challenges, the settlers used a technique called lithic mulching, spreading stones over the land to protect it from wind and improve soil quality. This method has also been used in other parts of the world, such as New Zealand and the Canary Islands.

Population estimates revisited

Some scientists have hypothesized that the island’s population must have been much larger to construct the massive Moai. However, recent studies based on satellite images and field surveys show that the stone gardens covered only a small portion of the island, supporting a maximum of around 3,000 people, the number observed at the time of the first European contact.

New findings with bachine Learning

Using machine learning models, researchers concluded that the stone gardens occupied less than 0.5% of the island. This supports the idea of a smaller, stable population with a diet based not only on sweet potatoes but also on marine resources and other crops.

Reassessing historical narratives

Carl Lipo, co-author of the study and an archaeologist at Binghamton University, notes that the idea of a population boom followed by collapse remains in the public imagination, but archaeological evidence does not support this:

“The accumulated evidence from radiocarbon dating of artifacts and human remains does not support the idea of enormous populations. The lifestyle must have been incredibly labor-intensive. Imagine a lifetime spent sitting and breaking rocks all day.”

Modern day Easter Island

Today, the island is home to nearly 8,000 people and receives about 100,000 tourists annually. Although most food is imported, some residents continue to cultivate sweet potatoes in ancient gardens, a practice that grew during the Covid-19 pandemic.

A case study in human adaptation

Seth Quintus, an anthropologist at the University of Hawaii who did not participate in the study, sees Rapa Nui as an example of human adaptation to a challenging environment:

“I see the island as a good case study in human behavioral adaptation in the face of a dynamic environment. The new study and others like it provide an opportunity to better document the nature and extent of adaptation strategies. Surviving in the drier subtropics of Rapa Nui, more isolated and geologically older, was an incredible challenge.”

Source: Columbia Climate School