Argument150 欢迎来拍 有拍必回！

SasakiKojiroUID: 2678315

Argument 150:
提纲：
1、
Y地的环境污染并不代表全球范围。
2、
Y地的数目下降不以为全球数目下降。
3、
可能有其他的因素，作者没有充分证明鲑鱼不是原因之一。
Comparing with studies in Yosemite National Park in California between 1915 and 1992, founding that species of amphibians in 1992 are less than in 1915, and the numbers of each species were drastically reduced, then, the author asserts the conclusion that the decline in the numbers of amphibians worldwide clearly indicates the global pollution of water and air despite of the introduction of trout into the park’s waters, which began in 1920. Convincing as the reasoning seems at the first glance, further reflection reveals that the conclusion is predicated on some dubious assumptions and biased evidences.

Firstly, the author seems to fail to show detailed information about air and water pollution in Yosemite National Park between the year 1915 and 1992. It is possible that there is average level in pollution between 1915 and 1992 in Yosemite National Park, or there may be a better environment over air and water in 1992. In addition, even if there is heavy pollution in Yosemite, the author still fails to show detailed evidence on the pollution in the world. Thus, lacking more detailed information concerning in pollution during 1915 to 1992 both on Yosemite and the worldwide, the reliability of these studies need to be called into question.

Secondly, the author equates the situation of the worldwide with the situation of Yosemite National Park. It is possible that the numbers of amphibians worldwide are not undergoing a decline compared with the numbers in Yosemite National Park, or the numbers of amphibians in the worldwide maybe even increasing. Consequently, the author shows no evidence on whether there is a decline in the numbers of amphibians worldwide.

Thirdly, the author seems to fail to explain the reason why the introduction of trout cannot be the real reason. It is possible that the trout that causes the decline of amphibians due to they eat amphibian eggs so that adult amphibian in Yosemite are much less than in the past. Lacking more detailed information about this reason, the argument seems to be less persuasive.

To reiterate, the argument of the author is not convincing as it stands, to make this argument logically more reasonable, the author would have to show the more detailed information on air and water pollution between Yosemite and the worldwide, and more studies should be taken to explain the reason why the introduction cannot be the real reason for the Yosemite decline.