Argument202 第一次发帖，恳请指正，谢谢：）

danhomUID: 2687956

TOPIC: 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.
WORDS: 414          TIME: 00:38:42          DATE: 2010-3-7 19:05:17

In this argument, the author cites the fact that a majority of large mammal species in the Kaliko died out and left no bones after humans arrived there. Base on which, the author assumes that humans cannot hunted the mammals. Hence, the author draws conclusion that it is the change climate or other environmental factor response to the species’ extinctions. The argument seems relatively sound; however, suffered from several logical flaws.

To begin with, the author fails to assume me that the humans are not credited for the species’ disappearance only based on the mere fact that "there is no evidence". The author ignores a host of other possible explanations for these phenomena, for example, the evidence was ruined out due to the radically changed weather; or perhaps scientists have not been able to find the evidence concerning these extinctions. Since the author fails to demonstrate these possibilities, the author's assume about this conclusion is unwarranted.

Similarly, the author unfairly observes a correlation between no areas containing the bones of large mammals and humans' influence; then concludes the latter has nothing towards the former. Lacking evidence about this causal relation, it is entirely possible that human hunted the mammal, and the bones are transported to other places that scientists have not found it; or the bones are buried in the soil and are disposed by the bacterium. Unless the author can demonstrate these possibilities are unlikely, it is hasty to justify that humans have no influence towards the mammal species' extinctions.

Even if the author can substantiate the two assumptions above, it is nevertheless to justify the conclusion that the change climate or other environmental factor is attributable to the species’ extinctions. Yet, this might not be the case for a variety of reasons. For example, during that period of time, the mammal species were killed out by there enemies in nature; or perhaps a plague breakout among the mammals and no one survived after that.
Without accounting for these alternative explanations, I remain unconvinced that the environmental aspect is the only reason to explain this extinct.

Overall, the conclusion lacks credibility because the evidence cited in the analysis does not lend strong support to what the author maintains. To bolster it, the author must provide information about evidence that can demonstrate humans' influence towards to the mammals. To reevaluate it, I also need to know other factors might be accounting for these extinctions.