#9 - Red admiral butterflies fly in a highly irregular

[Administrator]

Red admiral butterflies fly in a highly irregular fashion, a behavior that scientists interpret as a means of avoiding predation. After all, the red admiral is not a poisonous butterfly, so it needs to elude predators to survive.

Since the conclusion contains an explanation for an observed phenomenon, the reasoning is causal and can be diagrammed as follows:

Avoid predation (cause) Irregular flight style (effect)

The argument makes a number of questionable assumptions. While the flight style of the red admiral may not be energy efficient, maybe it has some other purpose. Or perhaps it has no purpose at all, and the red admiral is desperately in need of medication to manage an attention deficit disorder. Who knows? Alternatively, what if all butterflies fly in a highly irregular fashion, and the behavior observed is not unique to nonpoisonous butterflies? For the conclusion to be strengthened, the correct answer choice must establish a stronger connection between the irregular flight style of the red admiral and the purpose of avoiding predation.

Answer choice (A): This is the correct answer choice. If poisonous butterflies do not have the same irregular flight style as the red admiral, then the observed behavior is unique to those butterflies that need to avoid predation. While this does not prove the conclusion, it certainly strengthens it by showing that where the cause does not occur (poisonous butterflies do not need to avoid predation), the effect does not occur (their flight style is not irregular).

Answer choice (B): This answer choice does not help explain why the red admiral has an irregular flight style, and therefore cannot strengthen the causal relationship in the conclusion.

Answer choice (C): This is the Opposite answer. If many other types of butterfly have flight styles similar to that of the red admiral, then the behavior is not necessarily unique to nonpoisonous butterflies. This answer choice suggests that the irregular flight style of the red admiral may have some other purpose (or no purpose at all), weakening the conclusion of the argument.

Answer choice (D): We know that the red admiral’s flight style is not energy efficient (last sentence). Just because it would be even less efficient for heavier varieties of insects has no bearing on the argument at hand.

Answer choice (E): Whether the predators that prey on the red admiral also prey on other species of nonpoisonous butterflies has no bearing on the causal relationship that underlies the argument. Even if some predators preyed exclusively on the red admiral, the irregular flight style of the butterfly could still be a means of avoiding predation.

[cecilia]

Hi Powerscore experts..... Question regarding the first LR section from the June 15 exam,Question 9. I picked (A) only after process of elimination but in retrospect am still unclear as to how it strengthens.

How does havng “no” poisonous butterflies have irregular flight styles strengthen the conclusion that nonpoisonous adopt this strategy to elude predators. For ex, if, say, three or two or even just one poisonous buterrflies species had an irregular flight style- and a nonpoisonous butterfly adopted that same irreg flight style - wouldn’t this in a way help the nonpoisonous elude because the predator might think he’s a poisonous one because of his ability to act just like the poisonous ones??

Thanks in advance.

[David Boyle]

Hi Powerscore experts..... Question regarding the first LR section from the June 15 exam,Question 9. I picked (A) only after process of elimination but in retrospect am still unclear as to how it strengthens.

How does havng “no” poisonous butterflies have irregular flight styles strengthen the conclusion that nonpoisonous adopt this strategy to elude predators. For ex, if, say, three or two or even just one poisonous buterrflies species had an irregular flight style- and a nonpoisonous butterfly adopted that same irreg flight style - wouldn’t this in a way help the nonpoisonous elude because the predator might think he’s a poisonous one because of his ability to act just like the poisonous ones??

Thanks in advance.

Hello cecelia,

That's an interesting observation. Yes, it is possible that if there were a Blue Polka Dot Pattern butterfly which was not only poisonous, but flew funny, and the red admiral flew in a way that made predators think it was a Blue Polka Dot Pattern butterfly, that might scare off the predators too.
However, as for your main question: if some poisonous butterflies did fly irregularly, even though they have the built-in defense of being poisonous, that would make it less likely that flying funny is a defense against predators. However, if no poisonous butterflies flew irregularly, that makes it more likely that there is a reason for flying funny besides just wanting to fly funny: e.g., the red admiral may find flying funny confuses predators.

Hope this helps,
David

[cecilia]

Thanks David, but I guess my confusion still persists. Maybe i wasn't clear, but if a given situation could strengthen an argument, than how would ruling it out also strengthen that argument?

[Laura Carrier]

Hi Cecelia,

Your question is an interesting one and I think this will address it. From the stimulus, we know some things about two groups of butterflies (poisonous and nonpoisonous red admirals):

* Red admiral butterflies are irregular and unpredictable fliers, which is not energy efficient (so efficiency must not be the cause of this behavior).

* Poisonous butterflies are avoided by predators.

* Red admirals are not poisonous and thus need to be able to elude predators.

On the basis of these facts, the scientists hypothesize that the irregular flight style evolved as a means of avoiding (or eluding) predators.

This conclusion has a pretty strong implicit causal element, i.e., that the necessity of eluding predators caused the evolution of the irregular flight style. So if you were to ask me to weaken the argument in the stimulus, I would be thrilled to find an answer choice that showed the existence of the effect (irregular flight style) without the cause (need to elude predators).

The example you raised (where a poisonous butterfly would also have an irregular flight style) would be a perfect example of this kind of weakening, since the poisonous butterfly would lack the cause (the need to elude predators) but would still have the effect (the irregular flight style).

Conversely, answer choice (A) would be able to strengthen the scientists’ conclusion by showing that, where we know the cause is lacking, the effect never occurs either. Or, as David pointed out, “if no poisonous butterflies flew irregularly, that makes it more likely that there is a reason [or a cause] for flying funny besides just wanting to fly funny: e.g., the red admiral may find flying funny confuses predators,” which strengthen the implied causation in the stimulus.

Your suggestion that the existence of a poisonous butterfly with an irregular flight style (the logical opposite of answer choice (A)) would also strengthen the argument shows the kind of creativity and flexibility that will make a great lawyer!

But I want to caution you against choosing an answer choice like that on the LSAT, primarily because it doesn’t really stand on its own: You would need to help it out by speculating, as you did, that “the predator might think he’s a poisonous one because of his ability to act just like the poisonous ones.” Sometimes you do need to reason a bit beyond an answer choice to determine how it could be right—as in saying, "if poisonous butterflies never fly irregularly then that is an instance of the absence of the cause going hand in hand with the absence of the effect." But that would basically be taking the next logical step from what the answer choice already says on its face, whereas to make your scenario strengthen, you would need to add something speculative to prop up the answer choice.

I hope this convinces you to reconsider whether poisonous butterflies with irregular flight patterns really would strengthen this stimulus!
Laura

[cecilia]

Thank you so much Laura! Looking at it from a causal viewpoint really helped clear that one up. And yes, thanks for confirming that I perhaps added a bit too much to (A).

Thank you again.