#19 - European wood ants incorporate large quantities of

[Dave Killoran]

Complete Question Explanation

Evaluate—CE. The correct answer choice is (D)

The key to solving this Evaluate the Argument question is to get a solid read on the stimulus, so let's begin by reviewing what is said by the author, starting with the two premises that open the stimulus:

• European wood ants use a specific resin in their nests. This resin is also a natural disinfectant that kills bacteria that harms wood ants.

So far, we just have some basic facts about these ants and their use of the resin, neither of which is too difficult to follow. Based on these two facts, the author jumps to the following conclusion:

• The reason the wood ants use this resin is probably because of the disease protection it provides.

This conclusion is causal in nature ("came about"), although it reflects a more modern LSAT language usage and drops the certainty level down to "probably." Regardless, the author is saying the cause of the ants originally using the resin is because it protects them from disease.

The question stem is an Evaluate the Argument, which is a rarer type on the LSAT. That means that if you don't recall how these work, it's easy to get tripped up. In this case, we want an answer that helps us evaluate whether that conclusion is true or false, and so we should be looking for a statement or question that focuses on the resin, specifically whether it is the cause or not.

Answer choice (A): The stimulus is careful to mention that the use of resin "came about" in the conclusion, and so the focus is on the initial use of resin, and not its long-term properties.

Answer choice (B): At first there is a tendency to read into this answer, and think it might having something to do with various ant disease patterns that might be greater in winter or summer, but the problem is that there is never enough information to assess whether the season makes a difference. If the answer is "yes" to this question, then it could simply be a product of when the resin is available from the trees, and if the answer is "no," that doesn't have any effect either (at least not one we can knowingly determine). Since differing response to the Variance Test questions yield no difference in our evaluation, this answer choice is incorrect.

Answer choice (C): This question as stated does not have an impact on whether the cause of the resin use was the disinfectant properties, mainly because we don't know whether the resin kills the bacteria that attack other ant species aside from the European wood ants.

Answer choice (D): This is the correct answer. The argument concludes that the disease-protection aspect of the resin is why the ants first started using it, but if the resin affords structural benefits, then that may be an alternate reason the ants first started using the resin. If so, knowing whether this was the case would help assess the argument. If there are structural benefits as described, the argument would be weakened, and if not, then the argument would be strengthened. Those yes/no answers provide different evaluations of the strength of this argument, meaning this answer passes the Variance Test and is correct.

Answer choice (E): The focus is on the ants usage of resin, and so information about how the resin developed and is used by conifer trees is not helpful.

[L.J.]

I chose the wrong answer (E). I eliminated answer (B) because "at some times of the year than at others" was not mentioned in the stim. The answer (E) sounds out of the scope since the stim was talking about the ants' nests not "for conifer trees". Though (E) mentioned "disinfectant properties" and "disease-protection measure", I was still rather dubious about it, but since I have eliminated (A) through (D), this was the only one left for me to choose.

Besides, I don't see why (D) is correct since it talks about the "structural benefits". Does the "structural benefit" match the "disease-protection measure"? If so, how? Is it because the conifer resin is solidified? Thanks.

[Dave Killoran]

Hi LJ,

I've posted an extensive explanation above. Please let me know if that helps answer your questions here. Thanks!

[L.J.]

Thank you, Dave. Your answer cleared up everything. Now I know the question asked in answer (D) is to offer an alternative answer/hypothesis for the reason why European wood ants to use conifer resin. If this is not true, then the answer will strengthen the the disease-protection measure presented in the stimulus. So answer (D) is correct because it can bring out the answer we expected. I guess I can use this YES/NO test to solve this type of questions. It seems very helpful. Thanks!!

[hlee18]

Hello,

After reading the explanations above, I still am not sure why C is wrong. The conclusion is "... the wood ants' use of conifer resin probably came about as a disease-protection measure".

In other words, it doesn't specify "European wood ants", but wood ants in general, which means that the conclusion SHOULD apply to other species of wood ants. In fact, if this is proven to be true, it would further support the conclusion that DOES NOT specify that the use of conifer resin came about as a disease-protection measure for select species of wood ants, such as the European ones.

Moreover, even if D is true, that ".. the use of conifer resin affords structural benefits to European wood ants' nests", it doesn't necessarily help us to evaluate the strength of the argument. The author is specifying that "... use of conifer resin probably came about as a disease-protection measure", which allows room for other factors. He's not necessarily saying that disease protection measure is the ONLY reason, but it's PROBABLY the reason. So having a separate benefit of structural support doesn't necessarily seem to increase or decrease the strength of this argument.

I think the issue here is that having a separate reason for the use of the resin doesn't necessarily make it a mutually-exclusive reason to disease-protection measure.

Thoughts?

[Brook Miscoski]

hlee18,

You are correct that the stimulus starts off with "European wood ants" and then drops the "European" for the remainder of the stimulus. I wouldn't focus on that, since the stimulus heavily features causal reasoning that needs evaluation, and it's common for people to drop lead words while everyone understands that the topic hasn't changed. Still, you're correct--it's the LSAT, so it's worth looking at (C).

If (C) stood a chance, it would read "whether any wood ant species other than European wood ants..." Without that reference, (C) doesn't address the issue--it could be fire ants, or something like that.

Looking at (D), the stimulus asserted that because the resin helps ants resist disease, that's the reason the ants use the resin. The stimulus ignores the possibility that disease resistance is an accident and that the ants began to use the resin for some other reason. (D) addresses that possibility, and is exactly the kind of question that needs to be asked to begin to evaluate the stimulus. There would still be many other questions, but (D) is on topic, addresses an alternative cause, and is restrained to the correct group of ants.

[hlee18]

Brook, thanks!

[Henry Z]

I chose (C) because I thought the answer to the question in (C) would let us know whether the use of conifer resin is exclusive to wood ants, and how prevalent it is used. If only wood ants use it, and all of them use it, it surely strengthens the author’s argument, that is, the wood ants use conifer resin because conifer resin kills bacteria that can cause disease in wood ants.

Upon review, I realized maybe I shouldn't assume the answer to the question in (C) would come with anything more than YES and NO. That is, if yes, we only know there’re species other than European wood ants use conifer resin, but we don’t know what exactly those species are, and don’t know whether they’re wood ants, so we still can’t evaluate the argument.

Is that how I should read it?

[katehos]

Hi Henry,

Your proposed understanding of choice (C) highlights a great reason why it's not the most useful question to ask! We don't really know much about other species, if the bacteria in question would harm other species, or even if conifer resin would kill whatever bacteria harms other ant species, so it doesn't give us much to work with.

(D), on the other hand, is very useful because if resin has structural benefits for the ants' nests, then that might severely weaken the argument by offering an alternative reason for the use of conifer resin.

Hope this helps!
Kate