Day 165 Humans arrived in the Kaliko Islands about 7,000 years ago

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 were extinct. Previous archaeological findings have suggested that early humans generally relied on both fishing and hunting for food; since archaeologists have discovered numerous sites in the Kaliko Islands where the bones of fish were discarded, it is likely that the humans also hunted the mammals. Furthermore, researchers have uncovered simple tools, such as stone knives, that could be used for hunting. The only clear explanation is that humans caused the extinction of the various mammal species through excessive hunting.

Write a response in which you discuss one or more alternative explanations that could rival the proposed explanation and explain how your explanation(s) can plausibly account for the facts presented in the argument.

五问：

（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 were extinct. Previous archaeological findings have suggested that early humans generally relied on both fishing and hunting for food; since archaeologists have discovered numerous sites in the Kaliko Islands where the bones of fish were discarded”和“Furthermore, researchers have uncovered simple tools, such as stone knives, that could be used for hunting”是事实，“The only clear explanation is that humans caused the extinction of the various mammal species through excessive hunting”是结论，值得反驳吗？

（2）考古学家发现了大量被丢弃的鱼骨头，可能证明当时人类捕鱼，但是能说明人类也猎取哺乳动物吗？这二者之间有联系吗？在岛上发现了哺乳动物的骨骼吗？这个因果关系能达成吗？

（3）研究者发现的简单工具，如石刀，一定是用来打猎的吗？是否有可能是用来切鱼肉或者刻标记的呢？

（4）除了人类可能导致大型哺乳动物灭绝，还有其他因素会造成这一结果吗？你能列举一两个吗？例如：气候变化或者是环境恶化都有可能会导致大型哺乳动物因不能适应而灭绝。

（5）文中是否将 hunting与hunting the mammals简单地画上了等号？打猎一定是猎杀哺乳动物吗？即使真的猎杀了，一定会导致如此严重的后果吗？