[phoenix] Argument150 第10作业 by 3号 求P

ningbo1990UID: 2641538

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: 361
TIME: 00:30:00
DATE: 2010/2/26 13:54:33

The argument asserts that the global pollution of water and air caused the decline in the numbers of amphibians worldwide, then the author gives to study about amphibians disappeared in Yosemite National Park during 1915 to 1992 and then deny a assumption that it is trout caused the Yosemite decline because it cannot explain the worldwide decline to certificate the conclusion. It is obviously the analysis has some flaws. I will discuss them in turn.

First, the author fails to assert the global pollution of water and air causes worldwide amphibians decline. Maybe there are other reasons that may cause their numbers to decline such as more hunting happen to amphibians, weather changed these years makes some kinds of amphibians hardly to survive, and
foods these amphibians eat are decreasing. So, global pollution of water and air may just one factor that caused numbers of amphibians decline.

Moreover, the study of Yosemite is not reliable. The study states that they just observed little amphibians and each of them were reduced in 1992. There is a possible situation that large amount of amphibians researchers do not found, so we cannot conclude these species numbers were drastically declined. Even if their numbers are actually decreased, there is no evidence given to support the decrease were caused by global pollution of water and air. Maybe the decline was caused by over hunted or maybe caused by lacking of foods.

Furthermore, the reason why the trout cannot be the real reason for decline is unreal. Because the author fail to establish a relationship between the decrease of numbers of amphibians and worldwide decline, the trout maybe the real reason to explain the Yosemite decline. Grand that the decrease happened in Yosemite may impact the worldwide decline, the decrease reasons are both caused by trout and global pollution.

In conclusion, the argument has many facets need to improve. First, the author give conquer evidence to explain the decline of numbers of amphibians are caused by global pollution of water and air. Moreover, the argument should strength the reliable of the study. Finally, the argument should consider the trout as a reason for the Yosemite decline.