a150

believe39UID: 2598664

TOPIC: ARGUMENT150 - The following is a letter to the editor of an environmental magazine.

"The decline in the numbers of amphibians worldwide clearly indicates the global pollution of water and air. Two studies of amphibians in Yosemite National Park in California confirm my conclusion. In 1915 there were seven species of amphibians in the park, and there were abundant numbers of each species. However, in 1992 there were only four species of amphibians observed in the park, and the numbers of each species were drastically reduced. The decline in Yosemite has been blamed on the introduction of trout into the park's waters, which began in 1920 (trout are known to eat amphibian eggs). But the introduction of trout cannot be the real reason for the Yosemite decline because it does not explain the worldwide decline."
WORDS: 441
TIME: 00:33:32
DATE: 2009-8-13 21:06:41

In this analysis, the editor fully embraces the conclusion that the global pollution of water and air causes the dicline inthe numbers of amphibians worldwide. To confirm the conlusion the editior points out that two studies shows that there were seven species of amphibians and there were abundant numbers of each species in the park in 1915, while, the species and numbers of each species dramatically decreased in 1992 in Yosemite National Park. He or she also presents that the introduction of trout cannot be the real reason for the Yosemite decline, since it cannot explain the worldwide decline. Albeit this conclusion seems relatively sound, it is infested with flaws and drawbacks.

The marjor problem with the argument is that the editor fails to provide hte[X1] water and air is the exclusive reason for the Yosimite decline. Perhaps the climate in the world change[X2] so quickly that the amphibian can hardly adapt themselves to the temperature, or perhaps the food, those species which are extint eat is less for them to survive. Bisides, those extinct amphibians are hunted by the human beings. Lacking evidence about those possibilities,
editor cannot easily assume that it is the pollution of water and air causes the extintion of those amphibians.

Anthor flaw weakens this argument is that edtor fails to consider other alternatives to demonstrate the decrease of amphibians in Yosemite National Park. It is possible that the visitors in the park alway give food to those amphibians, but they do not kown that it do harm amphibians. Then amphibians die form[X3] this reason. It is also possible that trout is the major cause of the extinction of amphibians, because there is no evidence shows that there is no trout in other place in the worldwide. The editor fails to consider the root of cause.

Furthermore, it is so long time between two studies that the assumption by editor can hardly be convincing. The environment around the park might dramatically change within the period. Perhaps there exists much noise around the park which causes the extintion of some species of amphibians. On the other hand, the condition in the park is not similar to that in the worldwide. Without considering these aspects, the conclusion is at best unwarranted.

As it stands, the argument is specious and not well reasoned. To make it logically acceptable, the editor could have to demonstrate that water and air are the exclusive reason for the extintion of those amphibian. Besides, more information about the condition between the park and other places in the worldwide are the same. To better evaluate the augument, we need more information about the above-mentioned possibilities.