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54.Humans arrived in the Kaliko Islands about 7,000 years ago, and within 3,000 years most of the large mammal(哺乳动物) species that had lived in the forests of the Kaliko Islands had become extinct(灭绝的). Yet humans cannot have been a factor in the species' extinctions, because there is no evidence that the humans had any significant(重要的) contact with the mammals. Further, archaeologists(考古学家) have discovered numerous sites where the bones of fish had been discarded(丢弃), 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.
Write a response in which you examine the stated and/or unstated assumptions of the argument. Be sure to explain how the argument depends on these assumptions and what the implications are for the argument if the assumptions prove unwarranted.
In this argument, the author considers that human has nothing to do with the extinction of the large mammals on Kaliko Islands . However, this argument is less convincing.The author makes a number of assumptions based on his or her own mind instead of facts and specific information.
By showing that there is no evidence of human have any contact with large mammals, the author assumes that human and large mammals on Kaliko Islands have no relation. However, this assumption is less likely to be true. Perhaps there is some evidence of human contact with large mammals, but these evidences have not been discovered by humans.Moreover, 3000 is a long time.It is extremely hard for some evidence to last so long.Besides, there could be some relations between human activities and the extinction of large mammals on Kaliko Islands, but these relations are not direct ones. Though some relations are indrect, they could lead the large mammals on Kaliko Islands to die out.For example, human activities disturbed their habitat and made pollution to their environment. The evidence of indirect relations between human and mammals are extremely difficult to find. Thus, it is unfair for the author to assume that no evidences have been discovered means no evidence exists.
Besides, the author is assuming that human never hunt large mammals because no bones had been found.However, this is never likely to be true.Perhaps ancient people do hunt a lot of large mammals, but they throw the bones of the mammals into the river or into the valley so the archaeologists could not find them. Moreover, though human seldom hunt large mammals as their food, they may hunt the babies of them.As a result, the large mammals die out quickly. Since these babies had not grown into mature, archaeologists could not find large bones. Even though ancient people hunt those mammals less, they may do other things that cause the extinction.Perhaps there as so many people and they consume a lot of food which are available for the large mammals before. So these mammals starve to death.
What is more, the large mammals' death is caused by climate change and environmental factors are just the author's assumption.We could find no evidence to defense this opinion.Actually, we even have no idea about if the climate and environment changed during the ancient time.Even though the climate had changed, there is no evidence show that the change is directly related to the extinction of the large mammals.As a result, this point is unconvincing.
To sum up, this argument is less convincing.The author's conclusion is based on a number of assumptions rather than archaeological facts.In order to make the argument more convincing, the author is encouraged to provide specific evidence about human activities and mammals on Kaliko Islands . |
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