求拍~~~Argument207~~~处女作...

tonechowUID: 2755161

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: 431
TIME: 00:45:25
DATE: 2010-3-29 chenry 16:11:24

Grounding on the fact of the increased amount of ultraviolet radiation and declined population of salamander eggs in mountain lakes in the same period of time, then combining the factor that ultraviolet radiation is able to damage the delicate issues and salamander eggs have no protective shells, the author concludes that the ultraviolet will no doubt cause population declines in other species, just as it has in the salamander species. At first glance, this might be somehow reasonable, but careful scrutiny reveals several logic flaws and make it unconvincing.

First of all, the author assumes a causal relationship between increased ultraviolet radiation and the declined salamander eggs just because they happened in the same period of time. However, this might not be the case. Although the salamander eggs have no protective shells, it maybe has a membrane which is radiation-resistant. Furthermore, other factors might also lead to a decline in salamander eggs in mountain lakes, such as the pollution of the lakes, human activities which might break the ecological balance where salamander live, and the hunting, rather than the ultraviolet radiation. Even assuming that it is the ultraviolet radiation which cause the decline of salamander eggs in mountain lakes, it might not be the case in other area, since they are exceptional cases with the situation above. And the decline in this area doesn't indicate the decline of the total population. Lacking comparison to other controlled area which does not influenced by ultraviolet radiation, the author shouldn't generalize the cause too hastily. Moreover, how long does the observation last? Perhaps it was not so long enough to evaluate the variation of the trend of the eggs number, or perhaps the salamanders were just not in breeding stage during the research time.

Even assuming that the decline of the salamander eggs is due to the ultraviolet radiation, the author unfairly generalizes that the specific species represent the general trend of other species. In fact, mammal eggs are generated in their bodies and might not be influenced by ultraviolet radiation as salamander; most reptile eggs are protect by the hard shells and won't be destroyed as well. Without considering these factors, the author cannot convince me by this unwarranted assertion.

To sum up, in order to persuade the readers, the author had better provide more cogent evidence as following: (1) a control team of salamander which are not influenced by the ultraviolet radiation; (2) the detail information about the environmental and other factors in mountain lakes; (3) direct evidences which could indicate that other species will be also influenced by the ultraviolet radiation.