Logical Reasoning

PT107 · S3 · Q22 Biologist: Some speculate that

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Biologist: Some speculate that the unusually high frequency of small goats found in island populations is a response to evolutionary pressure to increase the number of goats so as to ensure a diverse gene pool.

Statements

Some say the reason there are tons of small goats on islands is a response to evolutionary pressure to ensure a diverse gene pool. (breeding with something that is very genetically similar to you, f.e. inbreeding, is less healthy than breeding with a member of your species that has a lot of genetic differences).

However,

A trait will only become frequent in a population if the trait contributes to reproductive success. So the only kind of reproductive pressure that would make goats smaller is if being a smaller goat resulted in more reproductive success than did being a larger goat.

Evaluate

Often, when an Inference paragraph gives us a prominent Pivot, then the correct answer ends up being a safe way to synthesize what comes before the pivot with what comes after (Reconcile the Pivot).

If we were to relate what comes after the "however" to what came before, it seems like this biologist does not quite agree with the "some people" in the first sentence.

They were saying that there are tons of small goats because having a diverse gene pool would be good for the goat species, and she is saying,

In short, .

In addition to Pivot words, we're also reading Inference paragraphs with an eye for Conditional and Causal words, and the last two claims are both Conditional ideas. They don't chain together. The last one is an application of the first one.

Because of this rule doesn't influence → doesn't influence reprod. success freq in population

the author can derive her final idea if we're not saying not an evolutionary that small goats → pressure that could have more reprod. influence frequency success of small goats

Goal

We have to be flexible, since we're just looking for the most provable answer, but our instincts might be suggesting an answer that sounds like safely worded version of the biologist's rebuttal takeaway.

22.

The biologist's view, if true, provides the most support for which one of the following?

  1. The evolutionary pressure to ensure

    Opposite

    This answer is making it seem like the stuff the biologist said actually was agreeing with the stuff that some were speculating. But the "however" is pretty clearly telegraphing the fact that the biologists two ideas (the 2nd and 3rd sentence) are meant to push back against the 1st sentence.

    31% picked this

  2. The unusual frequency of small

    Opposite

    If anything, our biologist would speculate that if there's a high frequency of small goats, then it is the result of the greater reproductive success small goats have in this island environment. She thinks that the trait of smallness would only result if smallness conferred a reproductive advantage over largeness.

    4% picked this

  3. Contrary to what some believe,

    Opposite

    We have no support for the idea that large goats achieve greater reproductive success. In fact, the two sentences the biologist told us are contradicting this notion. Given that the trait of smallness occurs in higher frequency than the trait of largeness, she would assume that small goats achieve greater reproductive success.

    1% picked this

  4. Correct

    The evolutionary pressure to ensure

    Why this is right

    Yup, this answer just did the ol' Reconcile the Pivot. Since this pivot was a rebuttal, reconciling what came before / after is going to usually sound like, "So that idea you heard before the pivot is wrong." A diverse gene pool is a reality that would help the entire goat species on the island, whereas the biologist is pointing out that the only evolutionary pressures there are that influence the prevalence of a trait (such as smallness) have to derive from greater reproductive success for those who have smallness.

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

    58% picked this

  5. A diverse gene pool cannot

    Not Biologist's View

    This is too strongly worded even for the Some people in the first sentence, but what should immediately stick out to us is that this idea advances the view of the people in the first sentence. Our biologist is disagreeing with that view, and the question stem is saying "if the biologist's view is true, then which answer should we believe". If her view is true, then we should believe that the view in the first sentence was wrong.

    5% picked this

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