phenix写作小组组员2号第四次A习作

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ARGUMENT202 - Humans arrived in the Kaliko Islands about 7,000 years ago, and within 3,000 years most of the large mammal species that had lived in the forests of the Kaliko Islands had become extinct. Yet humans cannot have been a factor in the species' extinctions, because there is no evidence that the humans had any significant contact with the mammals. Further, archaeologists have discovered numerous sites where the bones of fish had been discarded, but they found no such areas containing the bones of large mammals, so the humans cannot have hunted the mammals. Therefore, some climate change or other environmental factor must have caused the species' extinctions.


In an attempt to find the reason why mammal species became extinct, the authour adovates that some climate change or environment factor caused the extinctions and hunams not the reason by providing the evidence that humans did not have contact with mammals, that there are no areas to discarded the bones. At first glance, it seems to be some how reasonable, yet, analysis of this argument by a more complete test reaveals that all premises are dubious and they therefore cannot justify the conclusion.



To begin with, obviously,this argument from ignoring other aternatives is invalid. Despide that humans may did not have any significant contact with mammals is of courser possible, the author neglects other possibilities. For example, mammals' extinctions may result from humans destroying the forest where is the only place mammals can survive, and they cannot adapt to a new environment where they migrated. Another possible reason is that human killed all the mammals' preies so that mammals did not have food. If so, humans was the most important but indirect reason. Since the author do not adequately responde these possibilities, his claim is intenable. So these possibile causes need a seriously consideration.



Secondly, the argument embraces the fallacy of areas where bones have been discard are amount to humans hunted species. The reasoning is open to question for it is most likely here was ocean rather than islands millions years ago, so the bones of fish had nothing to do with humans. If so, there is no evidence to support the opinion that humans were inclined to discard bones in a area and whether humans hunted mammals are still a question. Again, another possible explanation for why we cannot see the bones is that humans may used mammals' bones as their weapon to protect themselves for the bones are hard and big. For that matter, the conclusion claimed by the author is unwarranted. Hence, it would be better to improve the argument by consider these factors.



In addition, even all premises mentioned above can be defended, this argument is still not logical compellng since the authou's hasty conclusion. Let us ask some question to reveal the complexity of this problem. Is there any evidence show that archaeologists will never find another evidence to prove that humans did not cause the extinctions? Is there other causes lead to mammals' extinctions? Why this argument do not offer any evidence to prove its conclusion that climate change caused extinctions? Avoiding these questions may mask other causes. So, a more complete understanding of the relation between humans and mammals would be beneficial.



To sum up, from the aforementioned analysis, we may safely conclude that this argument lacks credibility. Nevertheless, if the author can offer more sufficient evidences and then draw a better conclusion, I would render the argument acceptable.