Argument207【Triple Week】第9次练习by ahng

ahngUID: 2605383

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: 488          TIME: 00:30:00          DATE: 2009-7-29 15:38:28

Grounding on the fact that the Earth's ozone layer has been caused to thin allowing an increase in the amount of ultraviolet radiation, considering the evidence that the population of salamander that lays eggs in mountain lakes has declined, and taking account of the truth that ultraviolet radiation is known to be damaging to the delicate tissues and salamander eggs have no protective shells, the author of this argument concludes that the increase in ultraviolet radiation has damaged many salamander eggs and prevented them from hatching and what's more the process will cause population declines in other species. However, with close scrutiny, the argument suffers from several fallacies, rendering it unconvincing.

To begin with, the author fails to establish the causal relationship between the increment in ultraviolet radiation and the decrement in the salamander eggs. As we know, the changing amount of salamander eggs can be owing to different kinds of reasons. Perhaps the ecosystem surrounding the mountain lake has been influenced, which leads to the decrease in the species that salamander lives up to. Or perhaps, more of salamanders are being captured by our human beings. Many situations including the above can be an explanation for the decrement in the population of salamanders, also resulting in the decreasing amount of their eggs.

Furthermore, there is also no evidence to show that the eggs with no protective shells will also be damaged in the same way as delicate tissues. Common sense tells us that there are many differences between tissues and shells of eggs. It is also possible that the ultraviolet radiation can be beneficial to the eggs, which indeed need the energy of ultraviolet radiation.

In the next place, the author also does not provide any evidence to substantiate the fact that the ozone layer upon mountain lakes is in decline, since the statistics all over the world is not any good indication to a certain place. Maybe there is no industrial factory near mountain lakes, in which case the environment surrounding will not be damaged.

Last but not least, even if the process is the very reason for the decline in salamanders, the author is also unable to prove that it can also cause other species declining in population. As we know, different species have distinct conditions. Some other species may have eggs that have heavier shells and can be better in preventing the ultraviolet radiation. What's more, there are a lot of species that do not cultivate their next generations from eggs, such as mammals. In this case, the ultraviolet radiation does not make any sense.

To sum it up, the author makes an unconvincing conclusion by citing some one-sided evidence and illogical reasoning. To bolster the ideas, the author should take into account the different conditions of other species and the structure of salamander eggs. In order to better assess the argument, I would need more accurate statistics about mountain lakes and ozone layer.