#9 - Naturalist: The recent claims that the Tasmanian tiger

[Administrator]

Complete Question Explanation

Assumption. The correct answer choice is (D).

A Naturalist seeks to prove that the Tasmanian tiger is extinct, despite claims to the contrary, on the grounds that no hard evidence has been found in the region where it once lived. We are asked to identify an assumption required by the argument.

Two immediate prephrases should come to mind: first, that the absence of hard evidence is conclusive. In other words, if the Tasmanian tiger was still around, some hard evidence in the area would have been found by now. Second, the author assumes that because the tiger is not in the region where it once lived, it isn't anywhere at all. Put another way, the author assumes the Tasmanian tiger didn't pick up and move to another place after its natural habitat was taken over. Look for either of these ideas in the answer choices.

Answer choice (A): While this is a possible cause of the demise of the Tasmanian tiger, it is not necessary that the author assume this. The author might instead believe that the cause of the tiger's extinction was hunting, or a devastating disturbance in their breeding patterns.

Answer choice (B): This answer would, if true, actually hurt the argument, accounting for the lack of carcasses found in the area. The author would not assume something that works against his position in this way.

Answer choice (C): While the author does need to assume that some evidence would have been found by now if the tiger was still in the region, he does not have to assume that every naturalist in the area has searched for it, or that those searches must have been systematic. Answer C strengthens the argument, but it does not have to be true for the author to be correct.

Answer choice (D): This is the correct answer choice. Try the Negation Technique on this answer and you get "The Tasmanian tiger moved and adapted to a different region in response to the loss of habitat." This would destroy the argument that the tiger is actually extinct! It would not matter that no evidence has been found in this region, because the tiger went somewhere else! That is exactly what you want to see when you negate the correct answer to an Assumption question, and this proves the answer to be correct.

Answer choice (E): The author need not assume that those claiming to have seen the tiger are not experienced naturalists. He only needs to assume that whoever they are, they were wrong.

[BoomBoom]

Hello,

I was wondering how D is the best answer choice here. I answered E but C is also attractive to me. If someone could explain why D is the best I would appreciate it.

Thanks,

Chris

[Nikki Siclunov]

Chris,

Thanks for your question. Generally speaking, we need a bit more input from you before we delve into a discussion of a particular LR question. Ultimately, it won't be us who are taking the test; it's you! Our goal is to help you cultivate the analytical ability to approach these questions on your own, which is why you need to help us help you first.

Here's what I'd like you to do:

• 1. Describe your approach to the stimulus. Did you understand the argument, if any, from a structural standpoint? What is the conclusion, and what evidence is the author using in support of that conclusion?
  
  2. Did you prephrase an answer to the question in the stem? If so, what was your prephrase?
  
  3. What exactly made the two answer choices you have listed particularly attractive? Did you use any question type-specific test (e.g. Assumption Negation Technique) to differentiate between them?

Thanks,

[BoomBoom]

Hello,

Initially when I read this stimulus I felt very good going into the answer choices but when I read the 5 choices I hit a wall and felt like this question had so many holes in it.

[REDACTED - COPYRIGHT]

2. Prephrase: At first I thought the first premise allowed for the tigers to change areas and therefore an assumption might be needed to fill that hole, but then after reading the second premise and conclusion I felt there were holes in the argument regarding the naturalists not finding evidence in an entire region (maybe it was a really big region and there were few naturalists) and also the alleged sightings created a hole that needed an assumption to close it.

3. So when I got to the answer choices I left answers C, D, and E as contenders. They all seemed attractive based off my prephrase and I went with E because I thought the conclusion would be a good place for the assumption to be made.

I found this question to be very tricky and if you could show me where I went wrong and how to best attack this question I would appreciate it!

Thanks!

Chris

[Nikki Siclunov]

Hi Chris,

This is actually a very simple argument. One of the main issues you seem to be having is simplifying what you read, and focusing on what matters (and ignoring what doesn't). Here's what the argument boils down to:

Premise: The Tasmanian tiger's natural habitat has been taken over by sheep farming.
Premise: There is no evidence of the tiger's survival.
Conclusion: The tiger is extinct.

Basically, it's a causal argument: there is no trace of the tiger, so the tiger must be extinct. You may notice this is a classic logical fallacy, where lack of evidence for something is interpreted to mean that this thing doesn't exist. Of course, the tiger may still be around... maybe he moved to greener pastures someplace else.

So, what's the assumption? That the tiger didn't do that! Didn't move elsewhere, hide from the scientists, or pretend to be extinct. We are assuming that there is no other cause for the observed phenomenon (the lack of evidence of its survival), other than the obvious one - the tiger is no longer.

Answer choice (D) matches that prephrase - the tiger didn't move elsewhere. To verify that this is an assumption, negate it (using the Assumption Negation Technique) and check to see if the logical opposite weakens the argument. Of course, it does: if the tiger did move and adapt to a different region in response to the loss of habitat, then clearly it's not extinct. Boom! The conclusion is destroyed, proving that (D) contains an assumption.

The same cannot be said about any of the other answers you're considering. Let's negate answer choice (C): not every naturalist has looked systematically for evidence of its survival. Alright, so what? Maybe some of the naturalists were careless, so the tiger could have evaded them, but we can't really prove that. We don't have to assume that every naturalist was super careful: all we need to assume is that enough of them were careful to ensure that the tiger didn't hide anywhere. (C) contains an exaggerated language that is not typical of Assumption answers.

As far as (E) goes, why would it matter if they were experienced? Sure, if those who reportedly saw the tiger weren't experienced, it makes it more likely that they are wrong and shouldn't be trusted. But, this is the LSAT - don't attack the messenger, or the source, of the argument. (E) strengthens the conclusion, but it's not an assumption for it. Why? Let's negate (E): those who have reported sightings of the tiger are experienced naturalists. Does that prove that the tiger is alive and well? Hardly.

Hope this clears things up!

Thanks,