Easter Island Mystery Revisited


Researchers suggest climate change may have played a role in the demise of the native population

By Joe Spivak

The story of Easter Island and the native Rapa Nui is a cautionary one: man's expansion and abuse of the environment ultimately results in the collapse of civilization. Long taught in Environmental Science courses as the case study in how not to live symbiotically with your surroundings, recent studies have begun to suggest an alternate hypothesis as to why this civilization disappeared. Contrary to the established narrative of exceeding Carrying Capacity, deforestation, resource exploitation, war, starvation and ultimately cannibalism, scientists now think that something very different occurred here, challenging previous assumptions.

When early colonists first visited Rapa Nui, they brought with them the Polynesian rat, either by accident as stowaways on ships or as a protein source for consumption. While rats may be deemed unpalatable by our tastes, they actually make sense as a food source: exponential growth/reproduction rate, hearty, resourceful and omnivorous. These characteristics make rats highly adaptable, but also have the potential to make them disastrous to local flora and fauna. Add in the fact of no natural predators, excluding people and you have ‘Asian Carpocalypse', Polynesian rat style! Based on the reproduction rates of rats (doubling every six to seven weeks) in three years you could have a population of 17 million, more than enough to deforest the island. Further supporting this explanation is the fact that destruction of ecosystems by rats and other invasive species has been well documented in other locations.

The story of Easter Island is definitely a cautionary tale. However, it seems now like more of a warning to not jump to hasty conclusions and assign blame to the wrong species. I do not think you many would argue against man being good stewards of the Earth and doing our part to protect our resources, but to think that we would drive ourselves into extinction so wantonly seems short-sighted at best, just plain arrogant at the worst. Invasive Species are arguably the pinnacle of Darwinism. A new species moves in to an area and out-competes the local organisms to establish a new population in a new environment. This has been occurring since the dawn of life on this planet. However, the artificial introduction of these species by humans can and have radically altered established ecosystems in the past.

Extension Questions

  • What other examples of invasive species can you think of?
  • What are some of the ways that scientists have proposed to combat/control invasive species?