argument45 0906G三月底AW“永不言弃”互改小组第一周第二次作业 by MYcolting 2#

MYcoltingUID: 2563080

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."
北极鹿生活在加拿大极地区域的岛屿上。它们全年都通过冰块在岛屿间移动来寻找食物。它们的栖居地局限在那些温暖得足以维持它们所需的植物生长，并且在一年的至少某些时候冷到足以让岛屿间的海面结冰以使它们能够在岛屿间旅行的地方。然而，根据当地猎人的报告，鹿的数量正在下降。由于这一报告正好与最近导致海洋冰面融化的全球变暖趋势同时发生，我们可以得出结论：北极鹿数量的下降是它们无法按它们原有的迁移习惯穿越结冰海面的结果。
TS
  1 证据不足
    仅有猎人的判断是不够的 鹿的数量并不一定就真的减少了，可能是由于北极鹿迁移到别栖息地，而    猎人找不到  或者北极鹿的活动时间有变化 猎人碰不到了
  2 同时发生不一定就是原因
    可能是过去捕猎过多，造成鹿的数量下降  还有可能是鹿群爆发了大规模致命疾病  或者是正常的生    物种群数量的周期性变化
  3 急于概括
    冰融化到什么程度 是否足以威胁北极鹿的生存？   就算威胁到北极鹿的生存，但它们的栖息地是有    大量可食用植物的，也不一定就因为食物短缺而造成数量减少



In this argument, the author concludes 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 while the melt of the sea ice is because of recent global warming. At the first glance, the assertion may be convincing, however, after analyzing the essay carefully, I find some flaws which is questionable.

First of all, the evidence of arguer's conclusion is insufficient. It is irrational to judge that the population of arctic deer declines according to the reports of hunters. It is possible that the arctic deer has immigrate into another habitats which lead to the result that hunters are not able to find them or the activity time for the arctic deer has changed lead to the same result as the former.

Although the reports of hunters is precise, there is another question that undermine the author's conclusion. The speaker asserted that the reason for the melt of the sea ice is that these reports coincide with the recent global warming. Nonetheless, concurrence is not bond to be the reason. Maybe it is because of excessive hunter which makes the number of deer decline; Or the group of arctic deer break out a massive deadly illness that reduce the number of deer; Or this phenomenon is just a normal periodic change of group of the arctic deer.

Another unconvincing point is that the percentage of the melt sea ice. If the melt of the sea ice is not so serious that the arctic deer can still follow their age-old migration patterns across the frozen sea to seek food, the conclusion would be pull down. Furthermore, we can find the information that the habitat of arctic deer should be warm enough to sustain plants on which they feed and we can know that even the arctic deer can not live on the age-ole patterns they are still able to feed themselves on the plants grow in their habitat.

To sum up, the conclusion lacks credibility because the evidence cited in the analysis does not lend strong support to what the arguer maintains. To strengthen the argument, the arguer would have to provide more evidence concerning decline of arctic deer.