Montshire Minute: Easter Island

Originally aired during the week of October 1, 1999

Monday

What do Easter Island and world population have in common? Not much on the face of things. Easter Island is a tiny, remote atoll in the Pacific Ocean. From the island, you'd have to sail over 1000 miles in any direction to reach another place inhabited by humans. European explorers who stumbled across the island, including Captain James Cook, didn't stay long. What they discovered was a small group of natives eking out a living on a desolate windswept island, surrounded by hundreds of mysterious stone statues. Cook asked questions that have been echoed by others over the past few centuries. Like, how could primitive people with no tools or lumber build and transport such massive stone monuments? Why were many of the statues torn down and defaced by the natives? With no written records, and oral history being somewhat unreliable, the answers would have to be provided by science.

Tuesday

Most scientists believe Easter Island was settled by Polynesians, the skillful mariners and explorers of the South Pacific. Easter Islanders may also have had contact with Peruvians. Like the Incas, the sweet potato served as a one of their main staples. Their expert masonry is also similar to that of the Incas. Archaeologists tell us that the island was at one time richly forested with palm trees. The trees would have been necessary to build the large canoes islanders used for fishing. It's estimated that the human population of Easter Island reached a peak of 9000. But shortly before the arrival of Europeans in 1722, the island underwent radical change. Core samples from the island reveal deforestation, soil depletion, and erosion, which led to food shortages and population collapse.

Wednesday

There is not complete agreement on what caused the population collapse on Easter Island centuries ago. Many trees may have been cut down and used to roll the huge stone statues to the outer fringes of the island. Archaeologists also have discovered that much of the land was cleared to cultivate crops to support the growing population. In either case, deforestation would have resulted in soil erosion and food shortages, which probably had something to do with eruption of warfare and the breakdown of religious order. What makes this story so compelling is that the inhabitants couldn't escape strife or starvation simply by leaving the remote island and starting over somewhere else. There was no other place for them to go. In any case, the trees they needed to build large seaworthy canoes were gone. The survivors had to live with the consequences of their ravaged environment.

Thursday

At one time, there may have been as many as 9000 people living on Easter Island. By the time Jacob Roggeveen (ROG-o-veen), a Dutch sailor, reached the island in 1722, there were only a few hundred. Over the years, archaeologists have pieced together a history of Easter island that suggests population growth, overuse of resources, and warfare. Sound familiar? Some scientists believe this story holds a lesson for inhabitants of spaceship earth. In 1804 the world's population was about 1 billion. It took 123 years for the population to reach the 2 billion mark. But it only took 33 more years, in 1960, for the population to add another billion. Around October 12, the UN estimates the human population will reach the six billion mark. The problem of "Y6B" - how to support the world's growing population in the next century - may dwarf the "Y2K" problem we've heard so much about.

Friday

The population crash on Easter Island may serve as a useful lesson about the dangers of overpopulation. Economist Thomas Malthus made the connection between population and the earth's natural resources about 200 years ago. Malthus said that population tends to increase faster than food production. Unless growth is slowed by social planning or disasters like disease or famine, he said, there would be widespread poverty. Kind of a grim thought, huh? Today, scientists use the term "carrying capacity" to describe how many people the earth can support. Most scientists think the earth's carrying capacity is somewhere between 7.7 and 12 billion, close to United Nations estimates of world population in the year 2050. Researchers point out that if human population continues to expand, we're bound to run out of room sooner or later.