Q18 - Some killer whales eat fish exclusively

[christine.defenbaugh]

Question Type:
Strengthen

Stimulus Breakdown:
Conclusion: young seals start with aversion to all killer whales, then learn to ignore some.
Evidence: seals can tell the difference (by listening to the 'dialect') between the type of killer whale that's going to try to eat them and the type that's not. They avoid the bad ones and don't bother about the safe ones.

Answer Anticipation:
This explanation seems plausible, but so do a handful of others. Maybe the seals start off with no aversion at all, then learn to avoid the baddies. Or maybe they start off (somehow) with the knowledge that some are bad and some are okay. Supporting the given hypothesis over these alternatives would be bolstered by anything that made that one more likely than the other explanations. Maybe we have evidence of wee seals freaking out at the sound of any and all whales?

Correct answer:
C

Answer choice analysis:
(A) Other things the bad whales eat is out of scope. Doesn't support explanations for the seals' behavior. (Avoid making complex narratives like 'maybe the seals see the whales eating other things and thereby learn to be afraid.')

(B) What other fish can and cannot hear is out of scope. Doesn't explain how the seals came to their patterns of behavior.

(C) While this isn't evidence about babies, it is evidence about how seals react to 'new' whales. These whales are safe, but the seals don't know how to categorize them. The fact that they react to an 'unknown' whale by running away supports the idea that running away is the default, as hypothesized!

(D) Predators other than killer whales are out of scope! We can't extrapolate anything from that about their behavior toward the killer whales.

(E) This is tempting, as it explains how an alternative path would work - the seal started with no aversion, survived an attack, then gained an aversion thereafter. And if an answer makes an alternative path less likely, it thereby makes the proffered explanation more likely. But this explanation doesn't make that alternative path more or less likely - it just tells us how it could happen.

Takeaway/Pattern:
This is a classic 'phenomenon-explanation' structure. As such, the marine biologists aren't just supporting their hypothesis in a vacuum - they are supporting their hypothesis over all alternatives. Any work we do (strenthen, weaken, find assumptions) needs to be centered with awareness of how the potential alternative explanations fit in.

#officialexplanation

[Aadithya P712]

I wasn't a fan of answer choice C because the question stem says that the hypothesis is that young seals start an aversion to all seals but then learn to ignore those that do not eat seals. I understood that to mean that young seals figured out the dialect of the seal-eating killers whales and ran away from those seals, and then ignored all the other seals.

Based off this, my problem with answer choice C is that it doesn't really follow the hypothesis. It doesn't show that seals learn to distinguish seal eating killer whales and ignore all others.

[HughM388]

(E) This is tempting, as it explains how an alternative path would work - the seal started with no aversion, survived an attack, then gained an aversion thereafter. And if an answer makes an alternative path less likely, it thereby makes the proffered explanation more likely. But this explanation doesn't make that alternative path more or less likely - it just tells us how it could happen.

Takeaway/Pattern:
This is a classic 'phenomenon-explanation' structure. As such, the marine biologists aren't just supporting their hypothesis in a vacuum - they are supporting their hypothesis over all alternatives. Any work we do (strenthen, weaken, find assumptions) needs to be centered with awareness of how the potential alternative explanations fit in.

#officialexplanation[/quote]

I don't see (E) as providing "an alternative path"—the attacked seal doesn't necessarily lack an aversion; the whale simply misidentified its prey and got the better of the seal in that instance, which must happen, after all, for a predatory species to survive, despite any evasive behavior on the part of their prey—as much as it reinforces the second, more explanatory, and thus more important, part of the hypothesis: that seals will learn to ignore whales on the basis of their "chatter." (C) provides us with nothing to reinforce that more predictive, explanatory, and interesting aspect of the hypothesis (and that is what makes a hypothesis a hypothesis). Seals avoid whales—so what? That's not particularly interesting or explanatory, whether seals are evasive based on a default chatter-recognition "setting" or because they're instinctively frightened of large orca-looking marine mammals.

(E) therefore provides the most support to the actual matter of the hypothesis that attempts to explain seal behavior through identification of individual whales or a class of whales as distinct.

[DominicK729]

I spent a lot of time on this question and the best explanation I can come up with is that answer E doesn't say anything about seals starting with an aversion to all killer whales. As far as we know, a choice E seal could have started with no aversion to killer whales and then learned which dialects to avoid based on which groups try to eat it.

In effect, this is the reverse of the hypothesis. This seal could have started with no aversion and learned which groups to avoid, rather than starting with an aversion to all and learning which groups to allow.

[NickS909]

I spent a lot of time on this question and the best explanation I can come up with is that answer E doesn't say anything about seals starting with an aversion to all killer whales. As far as we know, a choice E seal could have started with no aversion to killer whales and then learned which dialects to avoid based on which groups try to eat it.

In effect, this is the reverse of the hypothesis. This seal could have started with no aversion and learned which groups to avoid, rather than starting with an aversion to all and learning which groups to allow.

I agree here. I almost picked E on review but ultimately C is much stronger. We really need to key in on the fact that the hypothesis is stating the seals start with an aversion to all, and then basically clear certain whales as being ok due to dialect, so the base condition (status quo) is an aversion to killer whales.

C supports that scenario by saying when an unknown dialect is encountered, the adult seal behaves in the same way a young seal would behave when encountering a dialect it hasn't cleared as safe yet: it avoids it and treats it as dangerous until proven otherwise. That's how I figured C strengthens.

E on the other hand insinuates the base condition is not to fear whales unless proven otherwise, which is the opposite of the situation in the stimulus. While it is close, it ultimately does not strengthen the progression of Fear all -> slowly filter out the safe dialects, because this seal learned to avoid based on dialect as opposed to learned to accept those whales as safe due to dialect.

[IrisH894]

In these questions (question type is strengthen, and the sitmuli explains a phenomenon), it's important to be aware of alternative explanations. Sometimes the correct answer eliminates or weakens an alternative explanation, and sometimes it boosts the proposed explanation. If the answer choice gives additional data or experimental results that's only compatible with one of multiple possible explanations, then it's either easily eliminated or should be chosen as the correct answer.
Right off the bat I can think of two other alternatives to the proposed hypothesis. Maybe harbor seals were born with the genetic disposition to avoid seal-eating whales and ignore fish-eating whales. Maybe harvor seals didn't start with a natural aversion to any whales, but learned the distinction through experience.
It's clear that A B and D are both out of scope, the the only answer choices worth pondering are C and E.
Notice that E is compatible with multiple explanations: maybe seals learned the distinction through experience (through surviving attacks by whales), and the mistaken attack by a fish-eating whale is just another data stored into their empirical data base. Maybe seals naturally avert seal-eating whales, and this anomaly taught the seal that it should also avoid fish-eating whales.
However, C is only compatible with the hypothesis proposed in the stimuli. If seals start with no aversion and learn to avert certain whales through surviving attacks, then they should be indifferent to the foreign dialect. If they are naturally born with the ability to distinguish between harmless whales and fish-eating whales, then they shouldn't have swam away from the harmless whale with a foreign dialect.