Reading Comprehension

PT127 · S4 · P2 · Q12 Inclusive Fitness Theory

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Mechanisms for recognizing kin are found throughout the plant and animal kingdoms, regardless of an organism's social or mental complexity.

Topic

Why kin recognition exists among animals and how it can be explained by different evolutionary theories.

Framework

Answer / Explain

Main Point

Scientists have several explanations for why animals recognize their kin: inclusive fitness theory proposes it’s to protect their own genetic legacy by helping relatives, but in some cases (like with tiger salamanders), avoiding kin may purely be for self-preservation to reduce risk of disease. *The Most Valuable Sentence is probably the last sentence of P2: and the last sentence of P3: *

P1: Introduction to Inclusive Fitness Theory

All kinds of organisms can recognize their kin, and one important theory (inclusive fitness) says this happens so creatures can increase the survival of their own genes—not just through offspring, but through relatives, too. This theory helps explain behaviors that don’t seem to benefit an individual directly, like sterile worker bees helping their family.

P2: Applying Inclusive Fitness Theory to Cannibalism

This theory is supported by studies of cannibal tadpoles: they usually avoid eating their relatives, which makes sense if they’re trying to protect their own genetic legacy. Occasionally, ultra-hungry tadpoles will eat siblings anyway—implying that self-preservation can sometimes override this behavior.

P3: Alternative Explanation—Disease Avoidance

But inclusive fitness isn’t the only answer! For tiger salamander cannibals, avoiding kin may actually just be about not catching deadly diseases, since they’re more likely to get sick from eating relatives. For them, kin recognition may not be about helping family, just avoiding illness and preserving their own life.

12.

The passage most strongly supports which one of the following statements about the mechanism by which cannibal spadefoot toad tadpoles recognize their kin?

  1. Correct

    It is not dependent solely

    Why this is right

    Sure, since the mechanism is "nipping", which means to take a tiny bite of something, the mechanism is not exclusively visual. Does this answer mean that the mechanism is partially visual? Nope. Not all NFL players are women. (true) Not all humans live on Mars. (true) Humans do not depend solely on peanut butter to breathe. (true) Whenever we see "not all / not necessarily / need not / not solely", it's only telling us that there is something that isn't what we're talking about. Not all NFL players are women. (true) at least one NFL player is not a woman. Not all humans live on Mars. (true) at least one human does not live on Mars. Humans do not depend solely on peanut butter to breathe. (true) humans use at least one thing to breathe that isn't peanut butter. This answer is saying, the mechanism by which spadefoot tadpoles recognize kin as at least one non-visual cue.

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

    71% picked this

  2. It is neither utilized nor

    Unsupported: not possessed by others

    We have no way to say whether non-cannibalistic tadpoles also do / don't have this capacity to nip at a fellow tadpole and detect whether it's a stranger or relative.

    12% picked this

  3. It does not always allow

    Unsupported: imperfect mechanism

    Do we have any evidence that this nipping mechanism makes mistakes? Does the passage mention false positives or false negatives? Nope. No support provided for mistakes.

    8% picked this

  4. It is rendered unnecessary by

    Opposite

    We are actually told specifically that this mechanism is being used after the tadpole has already made the shift from omnivorous to carnivorous.

    4% picked this

  5. It could not have developed

    Too Strong: could not have developed

    We don't have any way to say that "the only way a nipping kin-recognition mechanism could develop is if at least some members of a species are not omnivorous". We don't know whether other species (omnivorous or otherwise) do or don't also have this nipping mechanism for kin recognition.

    6% picked this

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