PT153 S2 Q18 ExplanationSome killer whales eat fish exclusively

Answer choices, explained

1. A

   Out of Scope: other marine mammals1% picked this

   Killer whales that eat seals also eat other marine mammals that are similar in

   The fact that the harmful whales also eat other big mammals doesn't tell us anything about how seals acquire their ability to distinguish between harmful / harmless whales.

   1%
2. B

   Out of Scope: most fish2% picked this

   Unlike harbor seals, which can hear killer-whale chatter even at great distances, most fish cannot hear that chatter,

   We really don't care whether other aquatic animals do / don't have good hearing. The seal has good enough hearing to distinguish between the harmful / harmless whales. We already know that from the evidence. We don't need to be reassured that they have good enough hearing. We want new information that helps us judge the means by which they figure out the difference between harmful / harmless dialects.

   2%
3. C

   Correct59% picked this

   When mature harbor seals first listen to the recorded chatter of killer whales that eat only fish but whose dialect is unfamiliar, the seals

   Why this is right

   This is a No Cause, No Effect answer in the sense that the story we're being sold is this: 1st 2nd 3rd seals are seals learn seals start born scared of dialects of ignoring the all k-whales harmful vs harmless ones harmless This answer is emphasizing that "until they learn to distinguish dialects, they are scared by the sound of k-whales". The fact that this is a mature seal makes the answer harder to compute, but it's establishing that a seal's default position to an unknown whale is "I'm afraid". Over time, the seal can be convinced that a given dialect is associated with harmless behavior, but it ain't takin' any chances at first. So "if a seal hasn't learned a harmless k-whale's dialect" (No Cause) "it has not yet learned to ignore it (it is still in the initial state of aversion)" (No Effect)

   Skill tested: Strengthen · how this choice captures the argument's function is the move to repeat next time.

   59%
4. D

   Weakens, slightly10% picked this

   Young harbor seals show no natural aversion to any seal predators other

   This makes the author's hypothesis less plausible. If seals are born with innate aversions to this predator (killer whales), then why wouldn't they have innate aversions to other predators?

   10%
5. E

   Unclear Impact27% picked this

   If a fish-eating killer whale mistakenly attacks a harbor seal, that seal, if it survives, will subsequently avoid all killer whales that chatter in

   According to this story, "being attacked" is the causal difference-maker that explains the difference between the attacked seal and all the other seals. Does it help the author's hypothesis to say that "being attacked > having a supposedly harmless dialect"? No, not at all. If anything, the fact that an attacked seal starts avoiding all whales with that dialect makes it seem like actions (attacks) speak louder than words (dialect). But more importantly, this answer says nothing regarding whether seals are being born with fear and acquire partial-trust, or whether they're being born with trust and acquire partial-fear.

   27%