August 09, 2011

Diamond wrong about Easter Island

Don't Blame the Natives

It was a rat that caused the sudden collapse of Easter Island's civilization

By Charles C. Mann
Much more broadly embraced is Mr. Diamond's claim: Rapa Nui once was much more rich and populous. [Dutch explorer] Roggeveen had remarked on the island's lack of trees and speculated that it formerly had been heavily forested. As the island's population rose, the popular theory goes, its people cut down all the trees for slash-and-burn farming and as rollers to transport statues. With the forest gone, Rapa Nui's soil degraded; unable to feed themselves, Mr. Diamond argued in his best-selling "Collapse" (2005), Easter Islanders faced "starvation, a population crash, and a descent into cannibalism." The fall was abrupt and overwhelming; scores of giant statues were abandoned, half-finished. Roggeveen had discovered a ruin—and a powerful eco-parable.

Books and articles by the hundred have pointed to Rapa Nui as the inevitable result of uncontrolled population growth, squandered resources and human fecklessness. "The person who felled the last tree could see it was the last tree," wrote Paul G. Bahn and John Flenley in "Easter Island, Earth Island" (1992). "But he (or she) still felled it." "The parallels between Easter Island and the whole modern world are chillingly obvious," Mr. Diamond proclaimed. "The clearest example of a society that destroyed itself by overexploiting its own resources," he said, Rapa Nui epitomizes "ecocide," presenting a stark image of "what may lie ahead of us in our own future."

No, it doesn't, write archaeologists Terry Hunt and Carl Lipo in "The Statues That Walked," a fascinating entry in the pop-science genre of Everything You Know Is Wrong.
And::The real culprit, according to "The Statues That Walked," was the Polynesian rat (Rattus exulans), which stowed away on the boats of the first Polynesian settlers. In laboratory settings, Polynesian rat populations can double in 47 days. Throw a breeding pair into an island with no predators and abundant food and arithmetic suggests the result: ratpocalypse. If the animals multiplied as they did in Hawaii, the authors calculate, Rapa Nui would quickly have housed between two and three million. Among the favorite food sources of R. exulans are tree seeds and tree sprouts. Humans surely cleared some of the forest, but the real damage would have come from the rats that prevented new growth.

"Rather than a case of abject failure," the authors argue, "Rapa Nui is an unlikely story of success." The islanders had migrated, perhaps accidentally, to a place with little water and "fundamentally unproductive" soil with "uniformly low" levels of phosphorus, an essential mineral for plant growth. To avoid the wind's dehydrating effects, the newcomers circled their gardens with stone walls known as manavai. Today, the researchers discovered, abandoned manavai occupy about 6.4 square miles, a tenth of the island's total surface.
Comment:  I haven't read Collapse, but I've read about it. Diamond mainly used indigenous cultures such as the Maya and Easter Island as examples of failed civilizations.

Since we don't know why these cultures collapsed, his theories were speculative at best. They seemed stereotypical to me: blaming indigenous people for not being smart or sophisticated enough to manage their resources. Like veiled suggestions that these people were uncivilized and savage compared to Westerners.

Now it turns out Diamond may have been completely wrong about Easter Island, the centerpiece of his arguments. Oops! Better luck next time, professor.

For more on Diamond, see Guns, Germs, and Steel and The Myth of Western Superiority.


Anonymous said...

The really bad thing is, there are Mayans that are still around. "Failed civilization" indeed! Fail.

Diamond's Guns, Germs, and Steel has an odd part saying that Monte Verde is a hoax, which has since been disproven, and is irrelevant to Diamond's thesis in the first place!

Jaine said...

As an aside, the kiore (Polynesian rat) did much less damage in New Zealand than the Norwegian rat.