Argument45(48)
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." 作者: MYTH-II小组 时间: 2007-3-18 10:30:11
1. Local hunter说的是不是可靠?也许arctic deer migrate 到其他岛上去了,hunter却以为decrease了,其实根本没有。而且hunter的report只是他个人的感觉,并不是基于scientific statistics,因此并不可信。
2. 都说了coincide了,怎么能表示warming和decrease之间有必然的cause and effect relationship呢?就算真decrease了,不是因为over-hunting吗?不是由于天敌入侵吗?不是种群的周期性减少吗?
3. 前面已经说了“cold enough, at least some of the year, for the ice to cover the seaseparating the island”。因此,就算global warming了,最多也只是减少冰冻的时间,不一定会导致完全没有冰冻期。即使完全没有冰冻期,鹿不会游泳吗?作者: Liangdan 时间: 2007-3-19 21:34:03
1.The assumption that the deer populations are declining, which is concluded according to the reports from local
hunters, is unwarranted. When and where did the local hunters find this situation that the deer populcations are
declining?
2.The arguer neglect many otthers factors probably causing the decline of the deer population such as the hunt of
the deers, the deceasing of the palnts on which the deer are feed, etc.作者: zwzw1 时间: 2007-3-19 21:54:59
1. Report correct? evidence of the decline?有可能统计并不完全,没有证据说明deer 一定decline,有可能还上升了
2. 同时发生误认为因果。认为warming是原因,有可能是hunter过多或者是food不足导致
A. 全球气温变暖,不代表这个地区温度也在上升,作者应该给出当地的气温记录来说明问题。
B. 即使承认这个地区气温变暖,鹿也不一定会死,可能它们会寻找其他陆地上的途径寻找食物。因而鹿群数目的下降也可能是其他原因造成的,比如:猎人的过度捕杀,或者鹿的某种食物减少,食物链产生问题。
C. 猎人的报告不一定真实,可能猎人只是由于最近捕杀鹿的数目少了就认为鹿群数目下降,而实际情况可能是由于鹿群因为天气变暖去其他区域寻找食物,或其他原因。作者: sun-leaver 时间: 2007-3-19 22:52:35
1,鹿的数量不一定是真的减少。可能只是local hunters没有发现, 鹿群为了躲避hunters而向别的地方转移
2,只是coincide with global warming trends。没有证据证明 Canada’s arctic 地区的冰真的融化了。
3,没有证据证明 鹿群不通过穿越结冰海面 会造成死亡
4,即使鹿的数量真的减少了,也可能有其他原因。比如,苔原面积减少作者: pengyanj 时间: 2007-3-19 23:25:21
(1) 反驳前提,鹿的数量是否真的如猎人所言下降了。没有证据显示,猎人的报告具有真实性。
(2) 即便事实正如猎人的报告,鹿的数量在下降,editorial没有排除其它可能导致鹿数量下降的原因,比如过度狩猎(over-hunting),或是鹿的天敌(natural enemy)数量增多减少了鹿的数量,也不排除外来物种(invasion of exotic species,不知翻译对不对哦?)入侵和病菌感染infectiousness of germina)的原因。
(3) 如果确定鹿的数量减少是因为unable to follow their age-old migration patterns,editorial没有证据表明这是全球气候的变暖导致。首先,气温上升的程度是否足以融化海洋冰块的融化,其次,如果是,是否有调研报告表明这些鹿觅食的路径已经融化了呢?