LR Question 19 Explanation
QUESTION TEXT: Ecologist: One theory attributes the ability of sea…
QUESTION TYPE: Flawed Reasoning
CONCLUSION: The sea butterfly’s chemical compounds aren’t the reason why sea butterflies can avoid predators.
REASONING: No individual compound deterred predators.
ANALYSIS: The ecologist tested each compound separately. But, sea butterflies have all the compounds, together. The ecologist should have added all the compounds to a food pellet, not just one compound per pellet. Sometimes things are safe individually but deadly in combination.
___________
- This didn’t happen.
Example of flaw: Some people say that sea butterflies use both compounds and appearance to avoid predators.
But that’s nonsense. Obviously everything in the world can only have one cause! - This is a different flaw.
Example of flaw: People don’t use Blackberry phones much anymore. And the crime rate has declined. So the decline in Blackberries caused the crime rate to go down. - This is a different flaw.
Example of flaw: Sea butterflies are sometimes able to avoid predators by inflating to seem dangerous.
So if a sea butterfly can’t inflate, it will definitely get eaten. - CORRECT. Sea butterflies have the whole set of compounds in them! The ecologist should have tested the whole set, rather than testing each compound individually.
- This answer describes circular reasoning. That didn’t happen.
Example of flaw: Sea butterfly compounds don’t work, because clearly the compounds are ineffective.
More Resources for Flaw Questions
- Flaw drills: Use these to practice making examples of abstract flaws.
- Intro Course lesson: This intro course lesson covers Flaw questions.
- Mastery Seminar lesson: This LR Mastery seminar lesson covers flaw questions.
I was between A and D and chose A because in a way, the Ecologist did presume that the two theories are incompatible. I thought that perhaps both theories are correct, and while the compounds alone may not help the sea butterfly avoid predation, the compounds combined with their appearance may help avoid predation. By testing only one of these two characteristics, the ecologist is presuming it is either one or the other, and if one is disproved (such as was the compound theory) then it cannot possibly contribute to its ability to avoid predation. But, it still could– it may need to be combined with the appearance characteristic in order to avoid predation.
My problem with D is that the stimulus didn’t necessarily say that the pellets were fed one at a time. Only that “predators ate the pellets no matter which one of the compounds was present”. In my head, I imagined a scenario where the predators were fed a bowl of the pellets that each contained a specific compound and the ecologist noticed that all were eaten, regardless of the compound contained. If there were 4 chemical compounds and the predator ate all four pellets at once, then this would not be a flaw.
Why would my reasoning behind why A could be right, wrong?
Good question. So, first: incompatibility would be stronger. Like saying “the pellets helped them avoid predators, therefore camouflage can’t have helped”. Incompatible means if you have one, you don’t have the other. That’s the opposite of this stimulus, which says we DON’T have one, and based that conclusion on direct evidence.
As for the pellet experiment, here we need to assume the scientists aren’t morons. I actually wrote to lsac about this when I thought a question was flawed, and they said we should avoid assumptions that paint qualified experts as idiots. In other words give deference to scientists not to screw up a basic idea of their experiment. It would make no sense to separate the compounds then mix them together again, so we ought to look elsewhere for the flaw first.
This is where lsac explains their reasoning on experts: https://lsathacks.com/lsac-responses/
Note: This is an old comment but I wanted to clarify the point.