Q13 - Tent caterpillars' routes between their nests

[kim]

13. (A)
Question Type: Strengthen the Conclusion

What are the potential weak points in this argument? The author describes a behavior _ namely, that caterpillars leave chemical traces to mark paths to food sources _ then concludes that caterpillars engage in communal foraging. There is a logic gap, however, between the behavior and the purpose of it. It’s possible that the chemical traces are present, but don’t effectively communicate food location information to the community. Answer (A) connects the dots, making it clear that the chemical traces can be read by the community as markers for food.

(B) weakens the conclusion. If the caterpillars cannot detect pheromone concentration, then the paths that supposedly mark food sources would be useless to the community.
(C) is irrelevant to the conclusion. We care only about what happens when they mark paths to the nest, not how long it takes.
(D) is irrelevant to the conclusion. Whether the pheromones are different from other animals does not affect the truth of the conclusion.
(E) is irrelevant to the conclusion. The argument concludes that tent caterpillars engage in communal foraging, which means they would have to communicate food sources to each other. Whether or not other species of caterpillars could detect the scent left by tent caterpillars is irrelevant.


#officialexplanation

[ericling]

I selected E instead, neglecting the "other species" totally. I think the reason why I selected E is that my mind was set to find one assumption mentioning "detectable".

But I have another question: is assumption question similar to "most support" question?

[monster_omiga]

Why is (D) wrong?

If the pheromones left by tent caterpillars are not different from the pheromones left by other animals, then how can a tent caterpillar know that it is following a route to food source left by another fellow caterpillar? If they can't tell the difference, then leaving pheromones will not be a way to communicate the food source and the conclusion fails.

Thanks in advance!

[jpchris3]

Hi, I also have the same question as above- why couldn't D be the correct answer?

[ManhattanPrepLSAT1]

But I have another question: is assumption question similar to "most support" question?

Correct answers to question stems that ask you to provide "the most support" for the argument frequently (but not always) represent an assumption of the argument.

If you provide an assumption of the argument you definitely help justify it. However, it's not always the case that when you help justify an argument that you've identified an assumption of the argument.

[ManhattanPrepLSAT1]

Hi, I also have the same question as above- why couldn't D be the correct answer?

Answer choice (D) does not help justify that there is meaning conveyed in the scent trails that the caterpillars are following. Maybe if the caterpillars and different kinds of scent trails, that might be helpful. But having different pheromones from other animals doesn't tell us that those pheromones are serving any specific purpose.

[crazinessinabox]

Sorry, I'm still having a hard time understanding how to eliminate (D). During my PT, I did narrow it down to (A) or (D), but ultimately chose (D) because I thought it was more widely applicable to the tent caterpillars. (A) struck me as odd because of the "hungry" tent caterpillar specification. The description struck me as somewhat silly and I wanted an answer choice that was more widely applicable to the tent caterpillar community. Of course, these were my split second instinctive thoughts during the test. Upon further reflection, I do think that (A) does a better job of strengthening the argument than (D).

For the sake of clarity, is (A) better than (D) because (A) strengthens by providing direct evidence for the conclusion, whereas (D) only eliminates a potential weakness of the argument?

[amil91]

Sorry, I'm still having a hard time understanding how to eliminate (D). During my PT, I did narrow it down to (A) or (D), but ultimately chose (D) because I thought it was more widely applicable to the tent caterpillars. (A) struck me as odd because of the "hungry" tent caterpillar specification. The description struck me as somewhat silly and I wanted an answer choice that was more widely applicable to the tent caterpillar community. Of course, these were my split second instinctive thoughts during the test. Upon further reflection, I do think that (A) does a better job of strengthening the argument than (D).

For the sake of clarity, is (A) better than (D) because (A) strengthens by providing direct evidence for the conclusion, whereas (D) only eliminates a potential weakness of the argument?

I think D is wrong because it gets away from the conclusion a bit. The conclusion is that tent caterpillars engage in communal foraging, which is conveying where food is located. If D were true, does this actually help prove that they are conveying the location of food? Sure maybe it can add just the slightest bit of support in saying that the tent caterpillars won't get confused by other species' pheromones, but we still don't know if they can actually even detect their own pheromones or that they can distinguish between higher concentrations of pheromones and lower concentrations. Also if you negate D and make it say that the pheromones are not different, that doesn't really hurt the conclusion that they are conveying information about where food is located, they can still be conveying it even if other animals pheromones are the same. However, if you negate A to make it say a hungry tent caterpillar is not more likely to follow heavily marked routes, then that pretty much destroys the conclusion that they are conveying the information of where food is located.

[kyuya]

Quick stimulus breakdown:

- Trent caterpillars leave more pheromones when coming back from food sources than when not
- therefore, they are conveying info about food to other members of the colony, nest or hive (communal foraging)

(A) This answer choices strengthens the argument.

If we look at the core of the argument, we see

- stronger pheromone scent from food to nest than otherwise
- therefore, helping others to find food intentionally

If a hungry tent caterpillar is more likely to go for the heavily marked routes, then it suggests it is doing so for the food, and therefore, adds strength to the idea that the scent was put there for the purpose of communal forging.

(B) This would weaken the argument.

If they cannot tell the difference between the concentration, then how would they know one pheromone concentration is for food, and the other is probably just aimless wandering? They wouldn't know, and the purpose of the heavier pheromone would remain unknown.

(C) This is just irrelevant, has no effect on the argument.

(D) This doesn't matter. Even if they are different, it doesn't make it the consequence of the pheromone any weaker or stronger.

(E) "other species of caterpillars" is where this goes wrong. We only care about tent caterpillars.

[jasonleb1]

Can someone go into a bit more detail of how A is right? I eliminated A because I thought the important part of the argument was the "communal" aspect of the caterpillar's behavior rather than the "foraging" aspect. A didn't give any support to the conclusion that the tent caterpillars are communal creatures so I chose E despite not liking the "other species" part of the answer choice because it clearly demonstrated that they were acting as a member of a community.

[christine.defenbaugh]

Thanks for posting, jasonleb1!

I'm so glad you asked this question!

When you decided that the 'communal' part of the conclusion was more important than the 'foraging' part of the conclusion, you were adjusting the argument to suit your own biases! We, unfortunately, do this all the time - it's one of the number one habits to break as we master the LSAT.

You're 100% correct that in order to actually make this argument rock solid, we would need to support the connection to 'communal'..... but we also need to support the connection to 'foraging'. If we were looking for, say a sufficient assumption, then we would need to make darn sure that we locked up both of those elements.

But that is not our job here. Our task is to support the argument, and there are a plethora of ways that we could potentially do it. And it's perfectly reasonable to start out thinking 'dang, how do we know they are communal? Maybe these caterpillars use these trails just so they themselves can get back to the food'. HOWEVER - you must remember that the answer choice could easily go a totally different direction, regardless of how reasonable your prediction is. You can't shoehorn an answer that seems tangentially related to your prediction into the job!

If an answer choice had actually addresses the assumption inherent in this argument about the 'communal' side of things, that could have been juicy. But (E) doesn't actually do that. Nothing about this answer shows me that tent caterpillars act 'as a community', because this isn't actually about the tent caterpillars! If other caterpillars can see the trails, that doesn't tell me that the tent caterpillars act communally.

Let's make an analogy: Students at the university often leave books on benches on the quad. I'll argue that this shows that the student body engages in communal sharing of books. Would it strengthen this argument about the community of this university if I show that tourists from out of state (who are not college students) sometimes see the books, and occasionally take a few? No! This tells me nothing about the behavior, or communal-ness, of the student body.

Switching our view to (A), I agree that it does nothing to support 'communal' - but it absolutely supports 'foraging'. Since BOTH of those parts of the conclusion need a helping hand, supporting 'foraging' is just as valid. The LSAT would never make me choose between them.

Remember, many arguments are flawed for a variety of reasons all at once. In other words, they make multiple assumptions. As a result, while a sufficient assumption answer must account for them all, a necessary assumption, flaw, strengthen, or weaken question may well only point out/support/attack a single one. And it might not be the one we notice first.

Does this help clear things up a bit?

[jeff.wongkachi]

When I did this question like some people in this topic I initially had trouble between A and D. I ended up choosing A because A simply adds more support to the argument.

A) This showcases a caterpillar conveying info to another one concerning the location of food which proves an instance of the conclusion to be correct
D) This COULD work but it requires extra assumptions like "these pheromones left by the caterpillars that are different from the other pheromones are also effective in conveying info to other caterpillars). This extra assumed step for me made me hesitant to pick this answer over A, which required nothing extra from me!

[zcxlwj]

Christine - I know it's been a while since your last post, but what a great explanation. Thank you.

[BrianM353]

I've read through a bunch of arguments on this and I still don't see how D is wrong.

The claim is that tent caterpillars are among the insect species that do X.

If tent caterpillars pheromones are no different, than how do we know the pheromones we're finding and using in our premises are from tent caterpillars?