Reading Comprehension

PT127 · S4 · P2 · Q13 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.

13.

The passage states which one of the following about the mechanisms that enable organisms to recognize their close genetic relatives?

  1. The mechanisms are most easily

    Too Strong

    Too Strong: most easily Too Strong: similar in all This is definitely repeating words from our Support Window (like social or mental complexity), but it's saying something strong that has no support. We were never told what the #1 most easy way to explain these kin mechanisms is, nor did the passage ever talk about assuming they have a similar purpose in all species.

    7% picked this

  2. Correct

    The mechanisms have become more

    Why this is right

    This was stated in the 2nd sentence of the passage (and our Support Window). Improvements in the general understanding of these mechanisms (the mechanisms have become more clearly understood) have turned some biologists' attention to (prompting interesting in) the question of why kin recognition occurs at all (the purpose they serve)

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

    57% picked this

  3. The mechanisms have become the

    Too Strong: only since

    We don't have any strong wording in which they stated that it wasn't until the 1960s that these mechanisms because the focus of any theoretical attention.

    2% picked this

  4. The detailed workings of these

    Too Strong: must Contradicted, if anything

    In the second sentence, it sounds like biologists are already prepared to start trying to fully explain the purpose of kin mechanisms. They've turned their attention to answering that question about purpose. That sounds like the opposite of, "We can't study their purpose yet. We need to wait until the detailed workings are better understood."

    8% picked this

  5. The mechanisms operate differently in

    Too Strong: exactly the same function

    This doesn't resemble anything in our Support Window. I can see someone being tempted by this because we learned that spadefoot tadpoles have kin recognition so that they can avoid eating their relatives (ya know, unless they're famished), whereas tiger salamanders use kin recognition to avoid eating a relative that might pass on a deadly disease to them. Is that serving exactly the same function? No, those were two different functions 1. i'd rather eat non-relatives, so the shared genes of my relatives can prosper 2. I'd rather eat non-relatives, because if I eat a relative who's infected with that bacterium, then I'm going to feel it extra hard

    26% picked this

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