0910G【Try Best】第二小组 argument150 by bittnt

bittntUID: 2295266

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: 342          TIME: 00:30:00          DATE: 2009-7-12 17:32:26

In this letter, the author argued that the decline in the numbers of amphibians in the worldwide explicitly shows the global water and air pollution. In addition, the author provides two studies in Yosemite National Park [YNP] to support the point. However, there are some fake reasioning in the letter and the two studies which may lead to be unfavorable to the conclusion.

Firstly, the decline in the numbers of amphbians worldwide may not clearly shows the global water and air pollution, although it may be truth that pollution leads to the number reduction of the amphibians. Since we know ecosphere has its own rules, and many other factors such as temparature, the duration of sunshine may also have influence on the changes in the numbers of amphibians worldwide. Hence, the reasoning of the conclusion in this letter seems unsolid.

Secondly, the author provides the data from the two studies of amphibians in Yosemite National Park in California, but the author doesn't shows the reasonable logic to support the conclusion of the letter. In addition, the relationships between the factors may not that kind of simple, the authors gives some implicit assumptions to constrain the conditions which can ensure the number reduction of amphibians are caused by the pollution.

Thirdly, the author provides the counterexample to support his conclusion. Although the decline in the numbers of the amphibians in the particular region may be caused by the introduction of the trout, the author argues that the numbers of trout may not increase globally and he deduces the air and water pollution may be the causes. Anyway, the author implicitly assumes the situation in the particular region is similar with the gobal region, which can not stand. The author does not provide the data about the numbers of trout and amphibians in the global region.

To sum up, the letter is unconvincing since the above reasons. To enhence the conclusion, the author needs to provide more datas to support his implicite assumption and also needs to eliminate the fake reasoning in the conclusion.