The author of the argument concludes that the extinction of large mammal species in the forest of the Kaliko was a result of environmental factors like climate change. Nevertheless, that conclusion is based on a number of inadequately supported assumptions. Without further information, we do not have sufficient evidence to determine the validity of the claim.

To begin the argument, the author claims that human cannot be a factor of extinction given there is no evidence of significant contact between the humans and the mammals. However, the fact that there is no proof found today does not preclude the possibility of contacts between them back then. The humans in Kaliko could have interacted with the mammals, encroached their habitats, competed for food with them, or even fought with them. Unfortunately, given that the mammals became extinct around four centuries ago, it would be a herculean task for such contacts back then to leave a mark behind – fossils of the animals or remnants of the artefacts discovered by scientists, if any, do not necessarily reveal all the stories that have happened to them. If that is the case, the claim of no contact between the humans and the mammals due to lack of evidence could be called into question.

Taking a step back, even if we were to give the benefit of doubt to the author’s claim that there is indeed no direct contact between the mammals and humans, it would not be prudent to conclude that therefore the islanders made no contribution to the mammals’ extinction. Even without direct contact, it is plausible that human activities had posed a significant threat to mammals’ survival, albeit indirectly. For example, the article cited discarded fish bones as a sign that the humans hunted on fish – this could have been the source of sustenance for those large mammals as well. The mammals may have lost in this competition for food with the humans, eventually leading to the dismal of their fate due to privation of food. Given that the humans are “new” inhabitants of the Kaliko islands who only arrived seven centuries ago while the mammals may have been the natives of the islands, these human “invaders” could have disrupted the ecosystem equilibrium of the island by adding pressure on food and land resources to the other animal inhabitants, contributing to the mammals’ eventual distinction.

One more spurious claim is that the environmental factors like climate change would be the cause of extinction on the premise that human factor is not relevant. It is problematic as besides human and environmental factors, there are a plethora of other variables that could determine the fate of the mammals. For example, the mammals’ demise could have been caused by internal rather than external factors. There could be a genetic deficiency of the species that eventually make them unfit for survival according to Darwin’s theory that “the fittest survives”. Therefore, it would be hasty to conclude that the mammals’ extinction is caused by environmental factors before one rules out the relevance of other factors.

Ultimately, unless the different gaps in logics aforementioned are addressed, the author’s argument that the extinction of large mammal species in Kaliko was a result of environmental factors like climate change fails to be convincing.