PrepTest 157
[lcid:3727] Prep Test 157 LSAT — Reading Comp — S4
Reading comp
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: D
The notes below walk through why it fits the stem and how to eliminate the rest.
Question Type
Science
Answer choices
-
AThere is strong evidence Remaining source text redacted.
Why choice A is not credited
We are looking for a situation involving interbreeding bird populations. This doesn't discuss interbreeding at all. A time-savvy test-taker would eliminate this without reservation, especially if they remembered that this illustrates the phylogenetic approach taken by the "splitters," not the biological species concept used by the "lumpers." -
BBird populations X and Remaining source text redacted.
Why choice B is not credited
This answer choice at least mentions interbreeding, so it warrants a closer inspection. However, it says that the populations interbreed in the wild. Based on the biological approach, these populations should be classified as the same species, irrespective of how they interbreed in captivity. For this reason, this answer choice is incorrect. -
CBird populations X and Remaining source text redacted.
Why choice C is not credited
We are looking for a situation involving interbreeding bird populations. This doesn't discuss interbreeding at all. A time-conscious test-taker would eliminate this without a second thought. Some test-takers who made a less precise anticipation may overthink the answer choice’s reference to being "isolated.” However, the passage referred to isolation as "reproductive isolation," which was defined as two non-interbreeding species (P1, S5). -
DAlthough bird populations X Remaining source text redacted.
Why choice D matches the stem
Question Type:
Application/Illustration
Strategy Overview:
Review notes on biological species concept and passage, if necessary, to anticipate key features of that concept
Answer Anticipation:
Making a few quick notes about both sides of the debate, or memorizing some basic facts about both sides, would help us recall that the "biological species concept" refers to the work of the "lumpers." And whether we need to review our notes or the passage or neither, we should note that lumpers classified bird populations as belonging to the same species when two species interbreed in the wild. So we should look for a situation in which bird populations interbreed in the wild and are classified as the same species or a situation in which bird populations do not interbreed in the wild and are not classified as the same species.
Answer Choice Explanation:
We were looking for a situation in which two bird populations interbreed and are classified as the same species, and this answer choice states exactly that. Don't overthink the morphological dissimilarities — we only need to focus on the interbreeding part.
Key Takeaway:
Because the debate between "lumpers" and "splitters" was central to this passage, and because we anticipated many detail-oriented questions, we mentioned it would be a good idea to note or memorize a few basic facts about "lumpers" and "splitters." Doing so would have saved a good amount of time and mental bandwidth on this question. -
EAlthough bird populations X Remaining source text redacted.
Why choice E is not credited
This answer choice at least mentions interbreeding, so it warrants a closer inspection. However, it says that the populations don't interbreed in the wild. Based on the biological approach, these populations should be classified as different species, irrespective of their morphological or genetic similarities. For this reason, this answer choice is incorrect.
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Discussion
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Started by JonathanGreen