Argument207【Triple Week】第9次练习by david36355

david36355UID: 2603992

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: 440 TIME: 00:30:00 DATE: 2009-7-29 17:28:30

Casting the case of the radiation and the declination of the salamanders, the author asserted a causal connection between the two irrelavant issues, and predicted a declination of the salamander population. However, the logic of the speaker is to be doubted, for the fallacies are to be revealed with close scrutinies.

Basically, the speaker founds his contents on the basis of several assumptions, while the credence of which is to be questioned. First, there is no more research about the ultraviolet ray would cause the ruin of the eggs, for the arguer laid his logic on one condition: the radiation is damaging to delicate tissues, conversely there is also no evidence clarifying the eggs are typically consisted by the very tissues. On the second hand, even if the protective shell is absent, the eggs might function in another way to fight against the ultraviolet ratiation. Without excluding other factors and proving the eggs are indeed suffering from the exposure to the radiation, we are not convinced of the damage of the aggs, let alone the declination of the species. In the end, the author also fails to give further explanation about the assumption, which predicts the salamanders will be prevented from hatching. According to the precondition the author mentioned above, the eggs are extremely afraid of the radiation, but not the salamanders. Therefore, the grown-ups would not cease their enthusiasm on egging everywhere, or the salamanders might also be clever enough to lay their eggs in the shade or cavern, thus the eggs are safe. In short, the assertion toward the declination of the salamanders is not bound to credible.

Additionally, the details of the known declination of the salamanders is not given, and we also need more information about the very animal. Fundamentally, a miriad of factors may harm the survival of the poor animal. Pollution, over hunting, other animals preying the salamanders, the migration of the salamanders, all provides a possibility against the speaker`s assertion. On the other hand, we are almost totally ignorant about what a salamander is, even where the animal lays its eggs. Had salamanders lay their babies underwater, underearth, in the caverns, or even merely with a plant covering, the conclusion would be easily tapped over.

Overall, the author overstated from the data given, while lacking the necessary account for the other possibilities. In order to make the conclusion convincible, the author has to give more information about the connection between the egg and the radiation, about reason of the happened declination, about the salamanders` living habit. Also, the possible factors which may also cause the declination of the animal should be ruled out.


后天就考试了，今天晚上走人= =……所以修改可以略去，以上。