The mimosa tree evolved in East Asia, where the beetle Bruchidius terrenus preys on its seeds. In 1785, mimosa trees...
GMAT Craft and Structure : (Structure) Questions
The mimosa tree evolved in East Asia, where the beetle Bruchidius terrenus preys on its seeds. In 1785, mimosa trees were introduced to North America, far from any B. terrenus. But evolutionary links between predators and their prey can persist across centuries and continents. Around 2001, B. terrenus was introduced in southeastern North America near where botanist Shu-Mei Chang and colleagues had been monitoring mimosa trees. Within a year, 93 percent of the trees had been attacked by the beetles.
Which choice best describes the function of the third sentence in the overall structure of the text?
It states the hypothesis that Chang and colleagues had set out to investigate using mimosa trees and B. terrenus.
It presents a generalization that is exemplified by the discussion of the mimosa trees and B. terrenus.
It provides context that clarifies why the species mentioned spread to new locations.
It offers an alternative explanation for the findings of Chang and colleagues.
Step 1: Decode and Map the Passage
Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| 'The mimosa tree evolved in East Asia, where the beetle Bruchidius terrenus preys on its seeds.' |
|
| 'In 1785, mimosa trees were introduced to North America, far from any B. terrenus.' |
|
| 'But evolutionary links between predators and their prey can persist across centuries and continents.' |
|
| 'Around 2001, B. terrenus was introduced in southeastern North America near where botanist Shu-Mei Chang and colleagues had been monitoring mimosa trees.' |
|
| 'Within a year, 93 percent of the trees had been attacked by the beetles.' |
|
Main Point and Argument Flow
Main Point: Evolutionary relationships between predators and prey can survive centuries of separation and geographic distance, as demonstrated by the rapid beetle attacks on North American mimosa trees.
Argument Flow: The passage establishes a natural predator-prey relationship that was broken by geographic separation, introduces a general principle about evolutionary persistence, then demonstrates this principle through the rapid success of beetles when finally introduced to North American mimosa trees.
Step 2: Interpret the Question Precisely
The question asks about the function of the third sentence in the passage's overall structure. We need to identify how this specific sentence contributes to the passage's organization and argument.
Step 3: Prethink the Answer
The third sentence states a general principle: 'evolutionary links between predators and their prey can persist across centuries and continents.' This comes after we learn about the separation of mimosa trees and beetles, and before the specific example that demonstrates this principle. The correct answer should recognize this sentence as presenting a general principle that gets exemplified by the specific case study.
It states the hypothesis that Chang and colleagues had set out to investigate using mimosa trees and B. terrenus.
- Claims the sentence states Chang's hypothesis
- Chang was monitoring trees, not testing this hypothesis
- The sentence presents a general biological principle
It presents a generalization that is exemplified by the discussion of the mimosa trees and B. terrenus.
- Correctly identifies the sentence as presenting a generalization that the mimosa/beetle discussion exemplifies
- This matches our understanding
It provides context that clarifies why the species mentioned spread to new locations.
- Claims the sentence explains why species spread
- It addresses what happens when predator-prey pairs are separated and reunited, not species movement
It offers an alternative explanation for the findings of Chang and colleagues.
- Suggests the sentence offers an 'alternative' explanation
- The sentence doesn't contradict findings but explains them