Reading comp PrepTest 157 · Section 4 · Question 15
Passage
Political arguments about biodiversity and the preservation of endangered species generally assume we know what a species is. Yet answering
Remaining source text redacted.
Passage walkthrough
Passage Summary Topic:
Science
Paragraph 1
Main Point:
There's a debate in how to classify bird species between "lumpers," who use the "biological species concept" to guide their decisionmaking, and "splitters" like Charles G. Sibley, who use an increasingly popular "phylogenetic approach," and this debate is likely to have political and economic implications.
Key Lines?
Paragraph 1, Sentences 4-5 (P1, S4-S5) - Def. of one side of debate ("lumpers")
P1, S6-S7 - Def. of other side of debate ("splitters")
P2, S2 - Important ex. of "splitter" (Sibley)
P3, S2 - Criticism of ex.
P4, S1 - Author's conclusion
Meta-Structure?
Describing a Debate: There's clearly a debate in this passage. On the one side, we have the until-recently dominant "lumpers," who use their biological species concept to group similar bird populations into one species. On the other side, we have the ascendant "splitters," who may include the controversial Charles G. Sibley among their ranks. They divide bird populations into separate species using the phylogenetic approach. A passage featuring a debate could either utilize a Describe a Debate or a Resolve a Debate Meta-Structure — it all depends on whether the author is passive or active in the passage. A passive author will generally describe the debate without taking a side or attempting to reconcile the two sides. An active author will argue that one side is preferable or that both sides can get along. The author spends nearly the entire passage describing both sides of this ornithological debate, which means this passage is better understood as a Describe a Debate passage. Accordingly, the main point will represent the two sides of the debate (or simply assert that there is a debate). However, there is an important wrinkle: the author's conclusion asserts that this debate "undoubtedly has political and economic stakes." This will need to be part of the main point as well.
List: This passage is also organized around a list: the two sides of the debate. This list is mostly confined to the first paragraph, although the "splitter" side gets fleshed out with the discussion of Charles G. Sibley in the second and third paragraphs. When the author organizes a passage around items on a list, it's a good idea to note or remember where each item was discussed. We're likely to get several Minor Detail questions about each side, so be prepared to refer back to your notes and passage as needed.
Examples: The author also makes good use of examples in this passage. The primary example is Charles G. Sibley, who is described in the second and third paragraphs. We also learned about a few examples of controversial reclassifications Sibley supported at the end of the second paragraph. We get an example of a criticism of Sibley's work in the third paragraph. Finally, we get an example of one of the political and economical implications of the species question at the end of the passage. When a passage has this many examples, we are bound to get a question about at least one of them. The question could be about the specific example itself or the general idea the example illustrates. So, let's list both:
First, let's note that many test-takers tend to overestimate the importance of people in passages. Such test-takers tend to think any person mentioned is likely to be the main subject. Call it the anthropocentric fallacy, if you'd like. Such test-takers will probably think Charles G. Sibley (who, in fairness, did take up a lot of real estate in this passage) is the main subject. Many wrong answer choices to the Main Point and other big-picture questions will try to entice such test-takers by emphasizing Sibley's centrality to the passage. We should start by noting that Sibley was just an example of one side of the central debate in this passage (notice how he was introduced — "The late Charles G. Sibley ... could be called a splitter" (P2, S1)). Second, this is an exceptionally detail-centric passage, defined by lists and numerous examples. Expect many minor-detail questions to follow. We'll probably have to look back at the passage more than we'd like to, but we won't have time to look back for every question, much less every answer choice in every question. If possible, try to remember the main point and memorize some basic facts about each side of the central debate. To the latter point, try to remember the following: "Lumpers" use the biological species concept, which focuses on whether populations interbreed in the wild. In contrast, "splitters" use the phylogenetic approach, which focuses on whether members of a population share a genetically traceable feature. Remembering those basic facts will help us avoid some unnecessary fact-finding missions in the passage.
Science
Paragraph 1
- Paragraph note
- Two approaches to classifying bird species: Lumpers (biological species concept) vs. splitters (phylogenetic approach)
- Views, minor Meta-Structures, and the author's attitude
- List of approaches, item 1: Lumper/Biological Species
- Group similar species together
- Interbreed in wild → single species
- Until recently dominant approach
- List of approaches, item 2: Splitter/Phylogenetic
- Divide similar species
- "Diagnosable" ancestry (distinctive, genetically traceable features) → single species
- Increasingly popular
- Author's attitude: "confusing and controversial exercise" (second sentence)
- List of approaches, item 1: Lumper/Biological Species
- Paragraph note
- of "splitter": Sibley's DNA-DNA hybridization and revisions to species classifications
- Views, minor Meta-Structures, and the author's attitude
- of Sibley's revision: North/South American vultures more similar to storks than European vultures (last sentence)
- of Sibley's revision: Loons and grebes not related (last sentence)
- Author's attitude: "controversial revolution" (first sentence)
- Paragraph note
- Criticism and defense of Sibley
- Views, minor Meta-Structures, and the author's attitude
- of criticism: Sibley making arbitrary interpretations of DNA evidence
- Sibley defense: For practical reasons must limit the number of differences we accept in the same species, even if this is "slippery"
- Paragraph note
- Author's conclusion: Political and economic implications of the species question
- Views, minor Meta-Structures, and the author's attitude
- Ex of implication: Increasing number of species increases the number of species needing protection (last sentence)
Main Point:
There's a debate in how to classify bird species between "lumpers," who use the "biological species concept" to guide their decisionmaking, and "splitters" like Charles G. Sibley, who use an increasingly popular "phylogenetic approach," and this debate is likely to have political and economic implications.
Key Lines?
Paragraph 1, Sentences 4-5 (P1, S4-S5) - Def. of one side of debate ("lumpers")
P1, S6-S7 - Def. of other side of debate ("splitters")
P2, S2 - Important ex. of "splitter" (Sibley)
P3, S2 - Criticism of ex.
P4, S1 - Author's conclusion
Meta-Structure?
Describing a Debate: There's clearly a debate in this passage. On the one side, we have the until-recently dominant "lumpers," who use their biological species concept to group similar bird populations into one species. On the other side, we have the ascendant "splitters," who may include the controversial Charles G. Sibley among their ranks. They divide bird populations into separate species using the phylogenetic approach. A passage featuring a debate could either utilize a Describe a Debate or a Resolve a Debate Meta-Structure — it all depends on whether the author is passive or active in the passage. A passive author will generally describe the debate without taking a side or attempting to reconcile the two sides. An active author will argue that one side is preferable or that both sides can get along. The author spends nearly the entire passage describing both sides of this ornithological debate, which means this passage is better understood as a Describe a Debate passage. Accordingly, the main point will represent the two sides of the debate (or simply assert that there is a debate). However, there is an important wrinkle: the author's conclusion asserts that this debate "undoubtedly has political and economic stakes." This will need to be part of the main point as well.
List: This passage is also organized around a list: the two sides of the debate. This list is mostly confined to the first paragraph, although the "splitter" side gets fleshed out with the discussion of Charles G. Sibley in the second and third paragraphs. When the author organizes a passage around items on a list, it's a good idea to note or remember where each item was discussed. We're likely to get several Minor Detail questions about each side, so be prepared to refer back to your notes and passage as needed.
Examples: The author also makes good use of examples in this passage. The primary example is Charles G. Sibley, who is described in the second and third paragraphs. We also learned about a few examples of controversial reclassifications Sibley supported at the end of the second paragraph. We get an example of a criticism of Sibley's work in the third paragraph. Finally, we get an example of one of the political and economical implications of the species question at the end of the passage. When a passage has this many examples, we are bound to get a question about at least one of them. The question could be about the specific example itself or the general idea the example illustrates. So, let's list both:
- Second and third paragraph: Charles G. Sibley, a controversial example of the "splitter" approach to species classification
- End of the second paragraph: North/South Am. vultures more closely related to storks than European vultures, an example of Sibley's controversial findings
- End of the second paragraph: Loons and grebes not related, an example of Sibley's controversial findings
- Third paragraph: Criticism of "arbitrary" nature of Sibley's approach, an example of the controversy surrounding Sibley's approach
- Fourth paragraph: Increasing number of species would increase the number of species needing protection, an example of the political/economic stakes surrounding species classification
First, let's note that many test-takers tend to overestimate the importance of people in passages. Such test-takers tend to think any person mentioned is likely to be the main subject. Call it the anthropocentric fallacy, if you'd like. Such test-takers will probably think Charles G. Sibley (who, in fairness, did take up a lot of real estate in this passage) is the main subject. Many wrong answer choices to the Main Point and other big-picture questions will try to entice such test-takers by emphasizing Sibley's centrality to the passage. We should start by noting that Sibley was just an example of one side of the central debate in this passage (notice how he was introduced — "The late Charles G. Sibley ... could be called a splitter" (P2, S1)). Second, this is an exceptionally detail-centric passage, defined by lists and numerous examples. Expect many minor-detail questions to follow. We'll probably have to look back at the passage more than we'd like to, but we won't have time to look back for every question, much less every answer choice in every question. If possible, try to remember the main point and memorize some basic facts about each side of the central debate. To the latter point, try to remember the following: "Lumpers" use the biological species concept, which focuses on whether populations interbreed in the wild. In contrast, "splitters" use the phylogenetic approach, which focuses on whether members of a population share a genetically traceable feature. Remembering those basic facts will help us avoid some unnecessary fact-finding missions in the passage.
Question prompt
Which one of the
Remaining source text redacted.
Why the credited answer is right
Credited answer: C
The notes below walk through why it fits the stem and how to eliminate the rest.
Question Type
Science
Answer choices
-
AClassifying biological populations into Remaining source text redacted.
Why choice A is not credited
As anticipated in the Last Thoughts second above, this answer choice attempts to assert the primacy of Charles G. Sibley. Sibley wasn't the most important subject in this passage — the debate itself was — nor did Sibley help resolve this debate. (Arguably, Sibley's controversy has only made the debate harder to reconcile.) So this answer choice completely mischaracterizes the subject of the passage and Sibley's role therein, so it is wrong. -
BAlthough scientists often disagree Remaining source text redacted.
Why choice B is not credited
There are two scientists who note that classification systems are arbitrary, both mentioned in the third paragraph. There's the scientist who criticized Charles G. Sibley, and there's Sibley. Unless this passage was written in some alternative universe in which there are only three scientists, that's not enough scientists to account for "most" scientists. This answer choice also over-emphasizes the discussion of classification systems' arbitrary nature, which was confined to just the third paragraph. -
CHow biological populations are Remaining source text redacted.
Why choice C matches the stem
Question Type:
Major Point/Main Point
Strategy Overview:
Reiterate the main point as we summarized it after reading through the passage, then find the answer that best matches with it
Answer Anticipation:
As discussed in the "Meta-Structure" section above, this passage utilizes a Describing a Debate Meta-Structure. In such a Meta-Structure, the main point will represent the two sides of the debate (or simply assert that there is a debate). However, because the author asserts that this debate "undoubtedly has political and economic stakes," that will also need to be part of the main point.
So let’s look for an answer choice that states the main point as we anticipated it: “There's a debate in how to classify bird species between ‘lumpers,’ who use the ‘biological species concept’ to guide their decisionmaking, and ‘splitters’ like Charles G. Sibley, who use an increasingly popular ‘phylogenetic approach,’ and this debate is likely to have political and economic implications.”
Answer Choice Explanation:
This answer choice matches our anticipation nicely. It asserts that there is a debate (or, in this answer choice's terms, a "controversial scientific issue"), as is often the case when the passage utilizes a Describe a Debate Meta-Structure. It also includes the author's conclusion from the final paragraph: that resolving this debate has "practical implications." Some test-takers might take issue with the reference to "the preservation of biodiversity," but this topic was raised by the author in the first sentence. Because this answer choice includes both the debate and the author's view, it best captures the main point.
Key Takeaway:
Three of the four wrong answers over-emphasized the importance of Charles G. Sibley. Clearly, the test writers expected many test-takers to do so as well. People are sometimes the subjects of passage, but not always. Experienced test-takers will pay attention to how people are introduced. Is the author introducing the person to make a point about that person? Or is the author introducing that person to make a point about something else? Here, the author introduced Sibley as an example of a "splitter" in the ornithological community. (See the first sentence of the second paragraph: "The late Charles G. Sibley ... could be called a splitter.") -
DTraditional methods of classifying Remaining source text redacted.
Why choice D is not credited
Another answer choice that over-emphasizes the role of Charles G. Sibley in this passage. The main focus of this passage was not Sibley's work or his revisions to classification systems. Instead, the focus was the debate. Sibley was merely an example of someone on one side of the debate. -
ECharles G. Sibley developed Remaining source text redacted.
Why choice E is not credited
Yet again, this answer choice places too much weight on the role of one Charles G. Sibley. The discussion of Charles G. Sibley was confined to the second and third paragraphs. This answer choice is missing the larger debate described in the first paragraph and the author's views conveyed by the last paragraph.
What this tests
Question analytics
Based on historical answer selection rates for this question.
Answer choice distribution
Accounts
Save your place across PrepTests
Bookmark questions, build weak-spot lists, and pick up exactly where you left off—built for serious repeat practice.
No payment yet. We will only email when accounts open.
Already have an account? Log in
Deeper help
Ask follow-ups on any step
Optional AI tutor mode will let you interrogate assumptions, compare answers, and drill weak patterns without leaving the page.
Human-written explanations stay primary; AI is an add-on when you want it.
Discussion
-
C vs D vs E 2 replies
Started by jordierose02