Reading comp PrepTest 119 · Section 1 · Question 21

Topic: Science

Paragraph 1

• Paragraph note
  • Phenomenon/Explanation
• Views, minor Meta-Structures, and the author's attitude
  • Phenomenon - North American pronghorn can run much faster than any current predator
  • Biologists - Difficult to explain
  • Recent Biologist Explanation - Evolved to run faster than predators that are now extinct (fossil record)

Paragraph 2

• Paragraph note
  • Relevant term; Biologist reaction to explanation; Author response
• Views, minor Meta-Structures, and the author's attitude
  • Term - Relict behavior - Present behavior due to long-extinct condition
  • Most Biologists - Distrust relict behavior hypotheses (like explanation from P1); only accept when all alternatives ruled out
  • Author - Evidence can support these hypotheses

Paragraph 3

• Paragraph note
  • Modern-day pronghorn evidence supporting relict hypothesis
• Views, minor Meta-Structures, and the author's attitude
  • Example 1 - Herding behavior (helps with predators; less per-animal food) explained by predation
  • Example 2 - Mating based on speed/endurance

Paragraph 4

• Paragraph note
  • Support that relict behavior happens
• Views, minor Meta-Structures, and the author's attitude
  • Example 1 - Stickleback fish respond to sculpins even when long free of them
  • Example 2 - Ground squirrels respond to snakes after 70-300k years
  • (Counter)Example 3 - Arctic ground squirrels don’t respond to snakes after 3m years
    • Author - Shows it doesn’t last forever

Main Point: While most biologists are suspicious of relict behavior hypotheses, there is evidence that the pronghorn’s speed is due to evolutionary pressure from long-dead predators.

Lines 5-8 - The phenomenon that needs explaining (could also be viewed as a question or a paradox)

Lines 8-14 - An explanation

Lines 19-21 - Why biologists are skeptical of that type of explanation

Lines 24-25 - Author is more positive on the explanation

Lines 26-27 - More Author support for explanation

Line 29 - First example

Line 38 - Second example

Lines 44-46 - Author pivots to general support for type of theory

Line 46 - First example

Line 52 - Second example

Line 56 - Third example/counterexample (concession/caveat by Author)

Phenomenon/Explanation - As with many Science passages, this one starts with a phenomenon in need of an explanation: the North American pronghorn is so fast that no predator comes close to catching it, leading to the question of why it developed such speed (Lines 1-8). This phenomenon receives an explanation from a Biologist, starting in Line 8 - the pronghorn’s speed developed in response to predators that have since gone extinct, a type of hypothesis known as a “relict behavior hypothesis” (Lines 15-18). When a passage has a Phenomenon and an Explanation, the Author’s preferred explanation (or her opinion of a key explanation) generally serves as the main point. In this passage, the Author argues in favor of this Biologist’s hypothesis despite general skepticism from the biologist community, saying that there is “much supporting evidence” for it (Lines 26-29) and that such theories are supported by other examples (Lines 44-46). Since the Author buys into the Biologist’s explanation, the main point of this passage is that explanation - that the pronghorn’s speed can be explained by the presence of since-extinct predators, as we stated above.

Examples - The Author hops into a lot of examples in this passage throughout Paragraphs 3 and 4, though they serve different functions. Paragraph 3’s examples are of behaviors seen in pronghorns that suggest they did face predation in the past, directly supporting the biologist’s explanation of the development of their speed. Paragraph 4’s first two examples are of animals that display relict behavior, supporting relict hypotheses in general and thus indirectly supporting the relict hypothesis of the pronghorn’s speed. Finally, Paragraph 4’s last example is a bit of a counterexample, showing a situation where a relict behavior didn’t persist. While the Author adds this in to add to information about relict behavior, we should view it as a bit of a counterpoint to her other examples since it shows an outcome that doesn’t support her main point.

First, the central Meta-Structure here could be viewed in a variety of ways - as a Question and Answer, or as a Paradox and Resolution. All of these Meta-Structures are strongly related to each other, and the primary difference between them is the language used to describe the relevant elements. This also implicates correct language in answer choices. Since they’re so strongly related, you should be willing to pick answers that use any of these words to describe the elements in the passage, as long as they make sense in the specific context.

Second, there is a subtlety here related to our Meta-Structures we should discuss, especially in light of the end of Paragraph 2 and the entirety of Paragraph 4. Because those two sections are about relict behavior hypotheses and not the specific situation of the pronghorn, you might have considered this a Generalization/Example passage, with the passage being about relict hypotheses generally and exploring it through the example of the pronghorn. However, the structure of the passage shows us that this isn’t the case. Whenever a discussion of relict behavior hypotheses comes up, it’s to back up the explanation about pronghorn behavior. At the end of Paragraph 2, the generalization is meant to rebut the presumption of most biologists, who don’t like these hypotheses - and the Author then immediately hops back to the pronghorn theory and the evidence supporting it. The last paragraph is also noted as serving to support the “general plausibility” of these theories, in order to strengthen the argument that it applies to the pronghorn’s behavior. So this passage is about explaining pronghorn behavior, and it uses support for the general plausibility of such a theory to support that conclusion.

Third, note the role of the third example in Paragraph 4. There, the Author brings up a situation where relict behavior doesn’t persist. This doesn’t back up her argument the way the other two examples do, as it shows a behavior that disappeared with time, suggesting that relict behavior hypotheses do have some issues - after all, if behaviors disappear over time and this one didn’t, it might thus have a modern explanation after all. As such, we should be careful with questions about the Arctic squirrels or about the Author’s overall opinion of relict behavior hypotheses, as she does bring up this example highlighting a situation where they don’t apply.