argument51 on7号作业，by 6号

hidewildUID: 2362646

TOPIC: ARGUMENT45 - 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."
WORDS: 539          TIME: 00:45:31          DATE: 2009-2-4 20:24:16

TS  1 温室效应虽然是冰层融化，但是融化程度不一定能够组织鹿群的迁移

2 鹿群数目减少这一事实的来源值得怀疑，也许鹿群只是近期没有迁移到猎人居住的区域

3 其他因素也可能造成鹿群数目减少


This editorial puts forward a conclusion that arctic deer population is declining according to a local hunters(去掉a)which is a result of their unable to follow their age-old migration patterns across the frozen sea（非限制性定语从句前面加逗号）. The author attributes this to the trend of global warming that has caused the sea ice to melt. I find this argument logically flaws mainly in the following aspects.

To begin with, the author fails to give evidence which can account that arctic deer can no longer travel across the frozen sea. Even though the trends of global warming do cause the sea ice to melt, it is entirely possible that the situation has not been such bad that the temperature is too high to allow the ice to cover the sea separating the islands. Lacking of such evidence it is unfairly to ignore the possibility that arctic deer can still migrate across the frozen sea. I cannot accept the conclusion that arctic deer population is declining as a result of their unable(inability)to last（不及物动词）their migration patterns across the frozen sea.

Even accepting the assumption that deer can no longer travel across the frozen sea, the authenticity of the decline in arctic deer population remains suspectable. Since the source of the information is some "local" hunters, it is possible that recently arctic deer haven't migrated to the place where the hunters live due to their unable(inability)   to travel freely to some point（s）. So I doubt whether arctic deer population is really declining.

Even if the arctic deer are unable to travel across on the ice which covers the sea separating the islands and the population of arctic deer is declining, the argument rests on the further assumption that it is these that cause the decline in arctic deer population. Since the editorial provides no evidence to substantiate this assumption it is entirely possible that the arctic deer can still find food in(on)the island where they can get and it is other facts which should be responsible for the decline in the arctic deer population. I noticed that the author mentions the information that arctic deer population are declining is according to the local hunters. I think it reasonable to assume that it is the increase in（of）hunter that caused the decline in arctic deer population. Other human being activities, in similar, can also have a negative effect on the survival of arctic deer. In addition, I can also make the assumption that ferns ,which arctic deer are feed(on)are dying because of the rise of temperature cause by global warming and hence lead to the result that arctic deer are famine to death.

In sum, the editorial's author cannot justify his or her conclusion that decline in arctic deer populations is the result of deer being unable to follow their age-old migration patterns across the frozen sea. To bolster the conclusion the author must provide better evidence that (1) Global warming prevents arctic deer from travel on ice that cover the sea separating the islands. (2)The population of arctic deer is declining for real. (3) It is their unable(inablity)to travel across the frozen sea that causes the decline in population of arctic deer. Otherwise, I will remain unconvinced of this argument.

TS都没有意见，语言简练点就更好了~