Argument207,第一次写argument，求拍....

zhusichao88UID: 2786754

TOPIC: ARGUMENT207 - It is known that in recent years, industrial pollution has caused the Earth's ozone layer to thin, allowing an increase in the amount of ultraviolet radiation that reaches the Earth's surface. At the same time, scientists have discovered, the population of a species of salamander that lays its eggs in mountain lakes has declined. Since ultraviolet radiation is known to be damaging to delicate tissues and since salamander eggs have no protective shells, it must be the case that the increase in ultraviolet radiation has damaged many salamander eggs and prevented them from hatching. This process will no doubt cause population declines in other species, just as it has in the salamander species.
WORDS: 417
TIME: 01:12:39
DATE: 2010-4-11 14:26:01
提纲，1题中没有提到该蜥蜴的整体数量的变化情况
            2题中没有给出是不是有其他原因
            3没有将受过紫外线照射的egg和没有收到紫外线照射的卵作对比
            4没有理由相信单一物种所发生的情况可以应用在其他物种上。


In this argument, the speaker claims that the increase in the amount of ultraviolet radiation, arisen by the thinning of the Earth's ozone, causes the decline of the population of a species of salamander that lays its eggs in mountain lakes. And the process will cause population declines in other species. To convince us the speaker indicates the ultraviolet radiation will damage the delicate tissue and the eggs of the salamander have no protective shells. Therefore the increased ultraviolet radiation will damage the eggs and prevent them from hatching. The argument is unwarranted in several aspects.

Primarily, the speaker asserts that the population of the salamander has declined; however, this data is unilateral that its realm involves mere one area that is the mountain lakes. It can not stand for the whole population of this salamander. Perhaps the number of the eggs have declined in this mountain lakes while have increased in other areas, and the average number are still unchanged.

Even if the whole population of the salamander has declined, the necessary connection between the decline of the population of the salamander and the damage to the eggs from the increase of the ultraviolet does not existed. Perhaps the change of the climate or the increase of the human hunting in this area causes the decrease of the adult salamanders--regardless of the radiation reaching the surface. And the speaker fails to compare the eggs which exposed in the radiation with the control that hatching in the same areas as the former expect the radiation exposedness.

Even the assumption that the decrease of the salamander are caused by the increase of the amount of radiation, the speaker should not assert that the process will no doubt cause the population declines in other species merely according to the decrease of the salamander. Perhaps other species living in this area can endure the increase of the radiation, or even the radiation has no effect on them, If so, the speaker's prediction will be questionable for other species.

In conclusion, the speaker's assumption is unconvincing as it stands, to better strengthen it some more information about the number of the whole population of this salamander should be offered in order to assess the real situation of this species, the speaker must show the data about the influence of the radiation for those salamander eggs as well. Finally, we need more information about the reaction from other species when composed in the radiation to evaluate the true effect of the ultraviolet for other species.