Passage Summary: A naturalist argues that a specific animal is gone forever because their home was ruined and experts haven't found any physical proof of them lately.

Conclusion: The Tasmanian tiger is definitely extinct.

Reasoning: The animal's habitat was destroyed by sheep farming long ago, and naturalists have failed to find physical evidence like carcasses or tracks despite reported sightings.

Analysis: The naturalist is relying on an 'absence of evidence' to claim 'evidence of absence.' For this argument to hold water, it must assume that if the tiger were still alive, we would have found physical proof by now. It also assumes the animal couldn't have adapted to a different habitat after the sheep took over. Look for an answer that bridges the gap between the lack of tracks/carcasses and the certainty of extinction.