GRE写作Argument模拟题7:Population Problem

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. His opinions based on the coincidence that recent global warming trends that have caused the sea ice to melt and the local hunter's report that deer population are declining. Seemingly organized logically, the argument is unconvincing in several respects. First, the reliability of the report of local hunter is questionable. The author didn't tell us how many local hunters report that deer population is declining; it's entirely possible that just a few, for example 3, hunters reported that, the deer population is not declining or even increasing. Or the author just asks hunters of one particular location, perhaps deer in that region happened to be declining at that time, but the overall population is not. Unless evidence was provided that the whole population of deer is declining, the judgment is unjustifiable. Second, even if the deer population are declining, the global warming trends just coincide with the declining population, there is no evidence showing that it's the global warming that causes deer population's decline. It quite possible that global warming trends do not melt the sea ice of Canada's arctic region and perhaps Canada's arctic region is becoming even colder, that deer are died because of lack of food. Without knowing whether the ice in arctic region of Canada are indeed melt or not, it's impossible to draw any reliable conclusion from the coincidence. Third, even if the global warming trend do melt the ice of Canada's arctic region, we can't make hasty generalization that deer population are declining is the result of deer being unable to follow their age-old migration patters across the frozen sea. Perhaps, the arctic deer needn't to across frozen sea, when global warming causes there are far too enough plants to guarantee their survival. Thus global warming has increased the deer population. Or, the deer population is declining due to other reasons such as the undue hunting activities. While the author overlook such alternatives, it's unlikely that his argument is logically justifiable. In sum, the author's argument fails to prove that the declining deer population result from being unable to follow their age-old migration patterns across the frozen sea. To strengthen his statement, we at least need evidence prove that the deer population is indeed declining and the global warming trend caused the sea ice in Canada's arctic region to melt. And we need further research that rule out other possibility that could cause the declining population.