Page 16 - INSIDER READING 일부

Insider R01-A1 2007.10.24 9:15 AM ˘ ` 26 ¿ ¿¡‰” 300DPI 100LPI

The extinction of megafauna, or large ancient mammals, occurred about the same time as the
appearance of man, so it has been theorized that humans were responsible for this extinction.
Some scientists suggest that humans may have over-hunted these animals and driven them to
extinction. There is no doubt that these animals were a valuable source of food for early man;
there is ample archaeological evidence for human consumption of them. For example, bones
have been found with marks indicating that stone tools were used to remove meat from them.
Those in support of the human extinction theory also point to evidence indicating that
humans caused the extinction of the giant lemur in Madagascar and the moa in New Zealand.
They claim that similar extinctions could have been perpetrated by humans in prehistoric
times.
Some scientists point to climate change as the most likely factor in the disappearance of these
animals. During the Ice Age, Siberia had more of a steppe-like climate with expansive
grasslands, perfect for supporting large, grass-eating mammals like the mammoth.
Unfortunately, as the climate changed after the Ice Age, the grasslands were replaced by
swampy tundra, causing many populations of megafauna to starve to death. Though humans
may have contributed to some degree to the extinction of these animals, it seems more likely
that they were already on the decline due to a loss of their main food supply.
Other scientists propose a third possible explanation. They theorize that these mammals,
especially in North America, probably succumbed to disease carried by some microbe, which
they called a "hyperdisease" because it was able to jump across species boundaries.
Unfortunately, though the hypothesis may be interesting, the scientists who support it have
found no proof that such a disease actually occurred. It seems, then, that it will still be some
time before there will be a universally accepted explanation for the megafauna extinction.

All of the following are theories of why megafauna went extinct EXCEPT:
(A) Climate changed destroyed their food source.
(B) Early humans over-hunted the mammals for food.
(C) A disease that could jump between species killed them.
(D) The mammals froze to death in a long Ice Age.

3. This is a large negative fact question that addresses the central idea of an entire passage. Answer
choices (A), (B) and (C) contain key details of the passage; underline the sentences that mention
these key details.

26 Insider Reading