#8 - The caterpillar of the monarch butterfly feeds on

[Administrator]

Complete Question Explanation

Weaken-CE. The correct answer choice is (D)

The author of this stimulus asserts the following causal argument:

Effect: The viceroy is seldom preyed on.

Supposed cause: The viceroy looks like the poisonous monarch.

As with many causal weaken questions, here we should probably seek a different explanation—most likely an alternative cause for avoidance of the viceroy (other than its resemblance to the monarch).

Answer choice (A): The fact that the monarch may have some natural predators does not weaken the author's argument about the viceroy and why so many avoid it, so this answer choice is incorrect.

Answer choice (B): This answer choice deals with the level of protection toxicity provides to each individual butterfly. Since it clearly does not deal with the question of why the viceroy is avoided, this answer choice is incorrect.

Answer choice (C): This answer choice is incorrect for much the same reason that answer choice (A) is incorrect; the existence of some (that is, at least one) natural predator does not affect the strength of the causal argument in the stimulus.

Answer choice (D): This is the correct answer choice, because it provides a very clear alternative cause for avoiding the viceroy: that butterfly is poisonous as well, and is to be avoided on its own merits. This certainly makes it less likely that the general avoidance of the viceroy is based on its resemblance to the monarch.

Answer choice (E): This has nothing to do with the question of why predators avoid the viceroy, so this answer choice is incorrect.

[mtp39]

Hello,

I'm struggling on how to best approach some of these weaken conclusion questions. For example, from the drills, I gathered that you could look at this question and form the following thought: "Just because of its visual resemblance to the monarch it is not necessarily true as to why/ indicative that the viceroy is so seldom preyed on." This thought process actually confused me and led me down the wrong path.

I'm able to clearly identify the conclusion - "the viceroy is so seldom preyed on because of its visual resemblance to the monarch" - but I'm struggling on what should be the phrase or idea that guides me through the answer choices. The idea of "weakening the conclusion" is a little vague to me. Any advice?

Thanks,

Mike

[Jon Denning]

Hey Mike,

Thanks for the question, and welcome to the Forum! This is something a lot of people struggle with in the early stages of their prep, so know you're certainly not alone.

For me Weaken questions really require a two-step process as you work through the stimulus and prephrase an answer choice. The first step is identifying the conclusion, and it sounds like you're doing well with that, so congrats! The reason that's so critical--and it's an absolute necessity in EVERY question that contains an argument--is because the conclusion tells you exactly what it is that the author believes. Once you know precisely what the author thinks is true, then you know exactly what it is you're meant to either describe (Flaw, Main Point, Method of Reasoning) or affect (Weaken, Strengthen, Justify).

For Weaken it's usually the next step that causes issues, and I believe this is where you're struggling a bit: just how does one attack a belief? What happens, sadly, for a lot of folks is that they attempt to be incredibly precise in their prephrase (their expectation of what the correct answer choice will say) and end up making predictions that miss the mark. Instead, let's consider a better way to predict how an answer choice could undermine a belief, and we'll use your example here to do it.

What might we say to decrease the probability that "the viceroy is so seldom preyed on because of its visual resemblance to the monarch" is correct? Truth is, I have no idea. There could be tons of statements made that would harm that belief. More specifically, there are two ways you could hurt the idea of similar appearance = seldom preyed on. First, you could just give another reason besides appearance (an alternate cause), which is pretty common and generally pretty easy to recognize. Maybe "the viceroy blends in well with its surroundings," or "the viceroy is most active when its main predators are asleep," or "the viceroy can spit a deadly toxin at attackers and predators have learned to avoid it..." And on and on the list goes. Secondly, you could actually show that the facts of the conclusion would lead to the opposite relationship of the one concluded. So something like "birds find the monarch delicious and actively seek it out as a food source." That means that a similar appearance should make the viceroy MORE likely to be attacked, not less.

But perhaps you can see the difficulty here. I'm trying to prephrase specifics, of which there are loads, and I can't know what the test makers will choose. So attempting to predict exactly what the answer will say in this instance is really an exercise in futility. Rather, let's imagine what any statement that would hurt this would have to do, what it needs to accomplish to have the desired effect. The answer, of course, is that it merely needs to show why the similarity of appearance might NOT be the reason for low rates of predation. Lots of specific ways to make that point, but each of those ways will fall into that particular category of outcome. Here's the prephrase I'd make: "which answer choice gives me a reason to think similar appearance might not be the reason for lower predation?" And then move aggressively through the answers looking for one to satisfy that expectation. What it actually says matters little to me. What it DOES is everything.

I wrote a blog post a while back about prephrasing that speaks a bit further to this idea. Here's the link if you want to check it out: http://blog.powerscore.com/lsat/bid/153 ... ing-part-i

I hope this helps and please keep us posted on your progress!

Jon

[mtp39]

Jon,

That was very helpful. Thank you. I realized that my inability to form an exact pre-phase was causing me anxiety prior to looking at the questions. Your explanation showed me that as long as I can identify the conclusion and look for answer choices that give other possible results from the relationship or other reasons for the conclusion I should be OK.

For this example, in particular, the author states that the viceroys are seldom preyed on because they look like monarchs. I want to attack that by looking for answer choices that may say the resemblance leads to more attacks or there is some other reason to why they are seldom preyed on. Did I synthesize that correctly?

Thanks again,

Mike

[Jon Denning]

Hey Mike,

Thanks for the reply! I think you've understood the point about prephrasing well: trying to predict anything with greater certainty or precision than you can confidently know is going to appear (that is, what you're sure the answer will say/do) is a waste of time, and liable to lead to frustration more often than to success. So that's the major lesson to take away from this.

For this particular conclusion the broad weakening idea is simply that "similarity of color isn't the actual reason viceroys are preyed on infrequently." So any answer that demonstrates that notion would attack the conclusion. As far as the specifics go, to me it seems likely the weakening answer would either show an alternate cause for low predation, or show that similarity of color should actually lead to greater predation (thus implying that the same appearance isn't the actual cause of the observed effect, that viceroys are seldom preyed upon).

I hope that helps!

Jon

[mtp39]

Yes, very helpful. Thanks!

[temiolof]

Hi,

It was difficult for me to find any answer choice attractive because I didn't make the connection that predators do in fact stay away from monarchs because of their toxicity. We are to make that assumption even though we are not told this clearly and it seems to me that there isn't enough reason to believe this.

Maybe predators can't tell that the monarch's are toxic, so they are still preyed on. Maybe predators eat the monarch's anyway and only find out the monarch's are poisonous after they're dead..when nothing can be done. Maybe predators don't prey on monarchs due to other reasons..perhaps because the predators can't digest butterfly wings/monarch's are good at camouflaging/the smell of monarchs repel predators, but not particularly because monarch's are toxic.

Essentially, we are not told that predators do not prey on monarchs as a result of the monarch's toxicity, so I did not realize quickly enough that I was to choose an answer that took this connection for granted, while also addressing a flaw in the argument (that the visual similarity between the two butterflies benefited the viceroy by causing predators to stay away from the viceroy).

Once I realized I was to make the first connection, I could easily see why answer choice D would be correct: it would imply that predators have a different reason altogether to stay away from viceroys, since viceroys are toxic all on their own. So their visual similarity may have nothing to do with why predators do not prey.

In trying to be surgically precise in dissecting this argument, I think I did not make a reasonable assumption necessary to arriving at the right answer choice. Is this really the case or might I be missing something else?

[Robert Carroll]

temiolof,

You didn't do anything wrong in failing to make that connection. In fact, the argument does not demonstrate that predators avoid the monarchs because they're poisonous. This is the argument's problem, not yours, and the failure to establish the fact that predators avoid monarchs is precisely a weakness of the argument.

Jon made reference to this in a previous post:

What might we say to decrease the probability that "the viceroy is so seldom preyed on because of its visual resemblance to the monarch" is correct? Truth is, I have no idea. There could be tons of statements made that would harm that belief. More specifically, there are two ways you could hurt the idea of similar appearance = seldom preyed on. First, you could just give another reason besides appearance (an alternate cause), which is pretty common and generally pretty easy to recognize. Maybe "the viceroy blends in well with its surroundings," or "the viceroy is most active when its main predators are asleep," or "the viceroy can spit a deadly toxin at attackers and predators have learned to avoid it..." And on and on the list goes. Secondly, you could actually show that the facts of the conclusion would lead to the opposite relationship of the one concluded. So something like "birds find the monarch delicious and actively seek it out as a food source." That means that a similar appearance should make the viceroy MORE likely to be attacked, not less.

I quoted what I think is the relevant context and bolded the exact statement I was thinking of here. Because the argument never says monarchs avoid predation, maybe they actually are eaten, despite their poisonous nature. Then the claim that viceroys are avoided because of a resemblance to monarchs makes no sense - if they look like the delicious monarchs, wouldn't they get eaten more?

There are multiple ways to weaken a cause an effect argument. What Jon mentioned is one way. What you were having trouble with was that you seemed to identify something missing in the argument, missing information which might actually weaken the argument. The missing information you identified never ended up being relevant to any answer. That's not because you did something wrong, but because there is such a range of weakening possibilities for any cause an effect argument that occasionally you'll identify a weakness in the argument that doesn't show up in any answer.

The correct answer here is correct not because it requires making an assumption, but because it emphasizes the already-lacking connection between monarch and viceroy appearance. If viceroys are toxic, then what does their resemblance to another species have to do with anything?

Robert Carroll

[lunalondon]

Hello PowerScore,

Apologies for all the questions - really struggling with these weaken qs!

I understand why D is correct but I do not see why A is incorrect. If some predators do not have a toxic reaction to insects that feed on milkweed plants, then that means that some predators may eat the monarch, which means that some predators may eat the viceroy too because it looks like the monarch. This would show that precisely because of its visual resemblance with the monarch, the viceroy may in fact be eaten more than the conclusion allows.

Perhaps the clue here is in the word "seldom" as the conclusion is not denying that the viceroy is eaten? Don´t know... really confused.

Thank you!

[Emily Haney-Caron]

Hi lunalondon,

Thanks for the question! You are on your way to answering it for yourself. As you note, seldom does not mean never, and the argument isn't that the viceroy is seldom preyed on - that's information we're going to assume is true here, because it is presented that way in the stimulus. Instead, the argument is that the REASON the viceroy is seldom preyed on is because it looks like the monarch. A doesn't weaken either part of the last sentence; A doesn't say that viceroys are preyed on more than "seldom" (it just suggests that they could still be preyed on some), and it doesn't do anything to the argument that the reason viceroys aren't preyed on much is because they look like monarchs. Even if A is true, there are still all the other predators that do have a toxic reaction, and therefore try to stay away from monarchs (and viceroys).