【kaleidoscope】第二次作业Argument45 by Atticuswang

atticuswangUID: 2663189

写的时候有些心不在焉……


45 The following appeared as an editorial in a wildlife journal.

"Arctic deer live on islands in Canada's arctic region. They search for food by moving over ice from island to island during the course of a year. Their habitat is limited to areas warm enough to sustain the plants on which they feed, and cold enough, at least some of the year, for the ice to cover the sea separating the islands, allowing the deer to travel over it. Unfortunately, according to reports from local hunters, the deer populations are declining. Since these reports coincide with recent global warming trends that have caused the sea ice to melt, we can conclude that the decline in arctic deer populations is the result of deer being unable to follow their age-old migration patterns across the frozen sea."

提纲：
1. 鹿群数量是否有大面积的减少不能够根据猎人的单方面report确定

2. 鹿群不能够在岛间迁徙的原因是可能小岛由于人类的开发不适合生存，而并不是由于冰的融化。

3. 还可能有其他原因导致鹿群数量的减少。

In this journal, the author concludes that the deer populations decline in arctic because deer can not follow their age-old migration patterns across the frozen sea. To support his conclusion, the author proposes the fact that deer migrate from islands to islands across the ice every year and assumes the global warming causes ice to melt and results in deer's failure of migration. However, I find the author's assumption is flawed in several aspects.

First of all, I doubt whether the reports from the hunters are persuasive enough to show that deer populations in all area of Arctic are declining. Since the author fails to mention that, perhaps the populations decline just in a few islands, therefore the author unnecessarily extends to all the Arctic area, and can not concludes that the global warming tread has caused the sea ice to melt for the reason that global warming affect every corner of earth.

Even if we concede the fact that deer populations are declining, it is presumptuous to assume that the sea ice melt thus deer can not travel to other islands. Admittedly, the global warming effect has raised the temperature, but it is not sufficient to prove this leads to the melt of sea ice. Moreover, other possibility exists which can also explain why deer populations decline: Maybe the sea ice does not melt at all, and the coast is explored by human and deer can not find their way to travel out. In a word, the author's arbitrary assumption that the sea ice melts is unreliable.

Moreover, the author ignores some other issues that may cause the decline of deer populations. First of all, I strongly doubt whether hunting is the main reason of this issue, for deer are rather precious animal and very appealing to most hunters. Secondly, perhaps many deer die from hunger or disease as a result of pollution, or maybe their habitat has been spoiled as a result of excess exploration of natural resources. Without taking all these cases into consideration, it is rash to conclude that deer's disappear is due to failure of migration.

To sum up, there is not sufficient evidence to support the author's conclusion that the decline of deer populations is their being unable to follow their age-old migration patterns across the frozen sea. To bolster this idea, the author should make sure whether large area of deer populations decline and offer evidence to prove this fact is involved with global warming. In addition, the author should also take other cases which will lead to deer's disappear into account to make his assertion more convincing.