argument150 我们的九月小组-----第二十一次作业

maggie-leeUID: 2220892

The argument in the letter is well-presented, however, not thoroughly well-reasoning. In the letter, the author claims that the reduce and extinctions of amphibians in the worldwide range is due to the global environmental pollution which sounds logical and convincing at the first glance, but a close scrutiny will reveal that the several flaws seriously undermine the argument.

To begin with, the author unfairly assumes that the causes of amphibians’ decreasing in Yosemite are the same as the causes in the worldwide range. As we know, Yosemite is merely a small area in the world, which has its own characteristics, geographical environment, climate, and so on. In other words, what happened in Yosemite can not represent the condition in other areas in the world. It is totally possible that the dramatic introduction of trout reduced the number of amphibians significantly in the past in Yosemite. Meanwhile, in most other areas of world, the unexpected considerable increase of the other kinds of amphibian eggs-eating fishes rather than trout also happened but due to the natural factors. Under this case, the decrease of amphibian in the Yosemite and in the whole world can not be attributed to the same cause.

Secondly, the author fails to consider other potential alternatives to explain the decline and extinction of amphibians in the world. Common sense tells us that global pollution of water and air are just two of the alternatives as the causes of such condition. Besides, other factors include the change of climate, the deforestation and the too much activities of human. It is entirely possible that the with the global warming and gradual changes in climate some amphibians no longer fit in with the local environment any more, and then get extinct. In addition, perhaps too many human activities have disturbed the habitation of the amphibians and some of their habitations have been explored for tourism and lands for growing corps.

The studies do not lend strong support to rule trout as a cause for the decline of amphibians. Even if we assume that the decline and extinction of amphibians is caused by the pollution of air and water, no evidence is provided in the letter to substantiate that the decline of amphibians is resulted from the cause except trout. To validate the conclusion, it is imperative for the author to do a detailed survey to analyze the potential causes, and rule out the false ones with evidence not just based on unwarranted reasoning.

To sum up, the author should not draw a hasty generalization without careful analysis. To make the conclusion more persuasive and acceptable, it is necessary to find out more relevant information and facts.

fanfancy1026UID: 2126743