Q9 - Naturalist: The recent claims that

[dan]

9. (D)
Question Type: Assumption
This argument is tricky. The conclusion made by the naturalist is that recent claims that the tiger is not extinct are false. In other words, his/her conclusion is that the tiger is indeed extinct. The evidence presented is that the tiger’s natural habitat was taken over by sheep farming, and that naturalists have no evidence of the tiger’s existence in the region. But, isn’t the author assuming that the tiger hasn’t moved to another region? Answer (D) expresses this assumption. Notice that when the assumption is explicitly stated, it helps to support the argument ("We can’t find evidence of the tiger here, and they haven’t moved somewhere else, so they no longer exist."), and that this assumption is absolutely necessary in order for the conclusion to be drawn.

(A) is tempting because it would support the argument. However, the author doesn’t need to assume that the tiger became extinct because of starvation.
(B) actually weakens the argument. If scavengers can destroy tiger carcasses, this may explain why naturalists haven’t been able to find evidence of the tiger’s existence (a reason other than extinction). This can’t be a necessary assumption if it goes against the argument.
(C) is tempting, but the author doesn’t necessarily need to assume that every naturalist has looked systematically for the tiger.
(E) is not a necessary assumption either. The author already states that the sightings are alleged sightings, so it is not necessary to assume that those who have reported sightings are inexperienced.


#officialexplanation

[LSAT-Chang]

Is (c) wrong because even if we negate it: "NOT every naturalist working in the Tasmanian tiger's natural habitat has looked systematically for evidence of the tiger's survival", it doesn't necessarily destroy the conclusion?

Even if NOT every naturalist looked around, perhaps the 10 out of however many naturalists in the region are the most skilled ones out there, and having those 10 people search for remains would be a sufficient indication of whether or not the animals are extinct, right?

And also, could I possibly say that (c) is wrong because the argument doesn't explicitly state how many naturalists searched, but rather just says "since then naturalists working in the region..." so it could be possible that the author is talking in terms of all naturalists?

Just want to make sure that I am eliminating the wrong answer choices for the right reason as it is normally the case that I eliminate wrong answers for the wrong reason.

[bbirdwell]

Is (c) wrong because even if we negate it: "NOT every naturalist working in the Tasmanian tiger's natural habitat has looked systematically for evidence of the tiger's survival", it doesn't necessarily destroy the conclusion?

That's true. In order to conclude that the tiger is extinct, it's not necessary for EVERY naturalist to look systematically. Since this isn't necessary, it's not a necessary assumption.

After analyzing the argument originally, we should be primed for the correct answer.

Evidence:
1. sheep farming took over the tiger's natural habitat
2. there is no evidence of survival in this region, such as carcasses or tracks

Conclusion:
It's extinct.

Gaps? Many. The two that stick out the most are the ole "absence of evidence is not evidence of absence" mistake in the reasoning, and that the tiger didn't simply move to another region (all evidence is about the one region).

This primes us to recognize (D) as correct when we see it. Also, negating (D) has a very damaging effect on the conclusion.