ARGU207

civilppUID: 2999177

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: 454
TIME: 00:30:00
DATE: 2011/2/18 16:55:56

The speaker claims that the thinner Earth's zone layer resulting in increase in the ultraviolet radiation that reaches the Earth's surface would cause population declines in other species, like it has in the salamander species. To support his argument, the speaker claims that scientists have discovered a decline in population of eggs laid by salamander in mountain lakes. The speaker also claims that the salamander eggs which have no protective shells may be damaged by the ultraviolet radiation, thus resulting prevention from salamander's hatching. The argument seems well-presented, yet through careful scrutiny, I find it suffers from several flaws.
To start with, the author unfairly assumes that there's a causal-effect relationship between the increase in ultraviolet radiation and decline in populations of salamander's eggs lying on the mountains. It is possible, for instance, that there's a increasing number of other species which may feed on salamander's eggs causing decline numbers of salamander's eggs. Or perhaps the pollution of mountain lakes has severely done harm to the salamander's eggs, which results in decline in eggs. Without considering these factors, or any other geographical, genetic, or biological factors, the author cannot convince me that it is the ultraviolet radiation that causes the decline in eggs of salamanders.
Secondly, the speaker fails to consider whether the mountain lakes is representative for other places. However, the speaker fails to provide evidence to support that. It is possible that the decline in eggs lying in the mountain lakes is an exception compared with other places due to the unique condition of mountain lakes that results in difference. To better support the argument, the author should provide more information about whether the mountain lakes is a representative place for all other places that laid with eggs of salamander, or otherwise I cannot be convinced with this unwarranted assumption.
Thirdly, even assuming that the decline in eggs of salamander is actually due to the effect of increasing ultraviolet radiation, the speaker's reference that the ultraviolet radiation that do harm to reduce the numbers of salamander can still effective to effect other species is open to doubt. Perhaps the salamander and other species are incompatible in many differences that might undermine the effect of ultraviolet radiation on eggs. It is possible that other species' eggs which have protective shells immune to the ultraviolet radiation. Without considering this scenario, I cannot believe the author's sweeping conclusion that the ultraviolet would also cause the decline in other species.
To sum up, the author should provide more evidence about whether the sample--mountain lakes is representative and other alternative causes that may result in decline in salamander's eggs. To better evaluate the argument, I would need more evidence about the difference between salamander and other species.