Appendix (for reading content...etc)
Read the passage 'Collapse of Easter Island'. On a piece of paper, take notes on the main points of the reading passage.
Reading time: 3 minutes
Collapse of Easter Island
Because of its remote location, only a few species of plants and animals thrived on Easter Island, and the water surrounding it contained very few fish. Nevertheless, beginning with extremely limited resources on an isolated island, the native people achieved a very advanced culture, as evidenced by the gigantic monolithic human figures that line the coasts, as well as by other artifacts. The complete collapse of this civilization is still a mystery, but several theories have been put forward.
One theory suggests that the natives of Easter Island cut down large palm forests to clear land for agricultural purposes, fuel for heating and cooking, construction material for pole and thatch houses, and canoes for transportation. In addition, hundreds of ahu, or large stone monuments, were constructed and moved to the coast on rollers made of tree trunks. Assuming that the trees could regenerate quickly enough to sustain the environment, they continued the deforestation, which, in turn, caused serious erosion.
Another theory presents a very different explanation for the decline in the population. Since there were few predators on the island, and an abundance of food, it is thought that rats may have hidden in the canoes of the earliest settlers. When the native people cut and burned trees, the rats prevented regrowth by eating the fresh shoots before they could grow into large plants. With little food and no wood to build canoes to escape, the people perished.
A third theory contends that the population was decimated by a war between short-eared and long-eared people on the island. According to oral history, a plot by the long-eared people to kill the short-eared people was discovered and the short-eared people struck first, driving the long-eared people to a ditch where they were killed and burned.
Now listen to the passage. On a piece of paper, take notes on the main points of the listening passage.
[audio|src:'\listening\toefl_advanced\CollapseOfEasterIsland.mp3'|wait:185]
Well, all of the theories explaining the collapse of the civilization on Easter Island have some serious flaws. Let's start with deforestation. A credible study by Hunt and Lipo provides evidence that even though the Easter Islanders cleared most of the forests, they replaced them with grasslands, which·would have prevented the erosion that supposedly made the ground impossible to cultivate. So the absence of trees, although serious in terms of shelter, cooking, and transportation, wouldn't necessarily have precluded an agricultural base that could have supported the population.
As for the theory that rats ate the new tree shoots, preventing the regrowth of the forests, it's probably true that rats contributed to a disruption of the island's ecosystem, but it's also likely that the native people used rats as a food source while they tried to establish a long-term plan. Rat bones have been found along with chicken bones in the garbage dumps on the island, suggesting that the islanders were eating rats as well as chicken.
Okay then, what about the fighting between the long-eared and short-eared people? Historical records confirm that when the Spanish Viceroy of Peru sent an expedition to the island in 1770, the explorers estimated a native population of about 3000 people, but four years later when Sir James Cook arrived, the population had been decimated. Some records indicate that more than two-thirds of the population had perished. But island tradition dates the war between the long-eared and the short-eared people at about 1680-that's about one hundred years earlier. And it doesn't add up, does it?
So, you see, we still have a mystery because none of the three theories really provides a scenario that explains why the civilization on Easter Island collapsed.
Summarize the main points in the lecture, and then explain how they cast doubt on the ideas in the reading passage.
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collapse of Easter Island flaws in theories
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deforestation
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cleared palms-ag, cooking, houses,
canoes
moved ahu à erosion
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cleared palms-ag, cooking, houses,
canoes
moved ahu à erosion
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rats
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rats in canoes
ate young trees à prevented regrow
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rats in canoes
ate young trees à prevented regrow
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war
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short v long ear
l burned in ditch
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short v long ear
l burned in ditch
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