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.
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.
五問:
(1)“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”和“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”是事實,“Yet humans cannot have been a factor in the species' extinctions”是結論,值得反駁嗎?
(2)沒有證據(jù)證明人類與哺乳動物有接觸,就意味著人類與哺乳動物一定沒有接觸嗎?是否可能證據(jù)存在,只不過尚未被找到而已?或者時間久遠,證據(jù)已經(jīng)消失。
(3)是否可能存在這樣的一種情況:人類與哺乳動物并沒有過多的接觸,但依舊造成了它們的滅絕?你能說一說這樣的可能性嗎?例如:人類破壞了食物鏈,人類活動造成環(huán)境污染,或者人類過度砍伐森林破壞了動物的棲息地等。
(4)沒有發(fā)現(xiàn)被丟棄的哺乳動物骨骼,就意味著人類沒有獵取這些哺乳動物嗎?你能否說說,在什么情況下人類可能會獵取了哺乳動物卻沒有拋棄它們的骨骼?比如:大型哺乳動物的骨骼非常適合用來制造工具,因此沒有被遺棄等。
(5)大型哺乳動物的滅絕不是由人類導致的,就一定是氣候變化或者是環(huán)境因素造成的嗎?是否有可能是該物種自身的原因造成的?比如:疾病或者其他天敵物種大量侵入等。