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 general

The author in this argument concludes how humans were responsible for extinction of various large mammal species of Kaliko Island, but the argument rests on questionable assumptions, and suffers from vaguely defined terms that make it impossible to validate the conclusion, each of these assumptions can be refuted.

Firstly, the source of the statement that humans arrived about 7000 years ago, and within 3000 years most mammal species were extinct has not been supported by any evidence. Even if this is supposed to be true, the author cites that "Previous archaeological findings have suggested that early humans generally relied on both fishing and hunting for food", but which archaeological study is the author referring to? Is this study truly representative of humans 7000 years ago? Even if this study is true, it is apparent that a study based on general human preferences all over the world might not be applicable to those from Kaliko Islands. It is even possible that humans started hunting and fishing after large mammals of Kaliko Islands were extinct, if this would be true it seriously weakens the author's argument.

Since it might not be true that humans of Kaliko Island relied on fishing and hunting, discarded fish bones could have appeared for many reasons. Such as, out of other mammals on Kaliko Islands some may hunt for fishes, or the fishes themselves might have flown ashore and natural causes would have caused their degradation. Even if it is supposed that humans did fish, it in no way concludes that humans might also hunt for mammals. The author has concluded this statement without presenting any evidence or logic, as it is highly possible for a species to have appetite for fishes and not for mammals.

Again as in previous claim the author cites a vague fact, that is "researchers have uncovered simple tools" this statement need additional evidence to be convincible, there is no mention of which research and most importantly how old these tools are. It is likely that these tools were used by humans of Kaliko Islands after large mammals were extinct, if this were true the authors argument would become very weak. Again even if one assumes that these tools were available before mammals were extinct, there is no evidence suggesting that these tools were used for hunting of mammals, as tools could be for numerous purposes such as house building, cloth stitching or wood cutting.

The gravest faults in the argument are its dependency on questionable archeological and research findings, all these faults in the author’s explanations, weaken the conclusion to great extent. To strengthen his or her conclusion the author should incorporate more factual data and present it in an articulate form.