The gopher tortoise, a species of land turtle, inhabits many widely separated areas throughout the state of Florida. The species...
GMAT Critical Reasoning : (CR) Questions
The gopher tortoise, a species of land turtle, inhabits many widely separated areas throughout the state of Florida. The species is threatened by a disease that has, in recent years, reached most areas inhabitated by gopher tortoises. The spread of the disease is puzzling, since gopger tortoises can contract it only directly from other, infected gopher tortoises, and gopher tortoises never venture more than a few hundred yards from where they hatched.
Which of the following, if true, most helps to explain the spread of the disease among Florida's gopher tortoises?
Passage Analysis:
| Text from Passage | Analysis |
|---|---|
| The gopher tortoise, a species of land turtle, inhabits many widely separated areas throughout the state of Florida. |
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| The species is threatened by a disease that has, in recent years, reached most areas inhabited by gopher tortoises. |
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| The spread of the disease is puzzling, since gopher tortoises can contract it only directly from other, infected gopher tortoises, and gopher tortoises never venture more than a few hundred yards from where they hatched. |
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Argument Flow:
We start with the geographic setup (scattered tortoise populations), then learn about a disease problem (widespread infection), and finally get the contradiction that makes this puzzling (limited movement means disease shouldn't spread between areas).
Main Conclusion:
The widespread disease transmission among gopher tortoises across Florida is puzzling and needs explanation.
Logical Structure:
This isn't a typical conclusion-based argument. Instead, it presents a puzzle by showing us a contradiction: tortoises live in separated areas and don't travel far (premise), disease requires direct contact (premise), yet disease has spread widely (premise). These facts don't fit together, creating the mystery we need to solve.
Prethinking:
Question type:
Paradox - We need to find an explanation that resolves the apparent contradiction between the disease spreading to widely separated areas despite tortoises only moving a few hundred yards and only contracting disease through direct contact
Precision of Claims
Geographic precision (widely separated areas vs few hundred yards movement), transmission method precision (only direct contact), and behavioral precision (never venture far from birthplace)
Strategy
Look for a missing piece of information that explains how the disease could jump between widely separated populations despite the tortoises' limited movement and direct-contact-only transmission. We need something that creates a bridge or connection between the separated populations that wasn't mentioned in the original argument
Gopher tortoise hatchlings are preyed on by racoons and other animals, but adult gopher tortoises have no natural predators in the wild.
This information about predation patterns doesn't help explain how disease spreads between widely separated areas. The predator-prey relationships mentioned here don't create any mechanism for disease transmission across geographic barriers, since the predators aren't moving infected tortoises between areas or facilitating direct contact between tortoise populations.
People frequently pick up gopher tortoises and take them home as pets before letting them go in places where they have seen other tortoises.
This perfectly resolves our paradox! Human intervention provides the missing link we need. If people are collecting tortoises from one area (some potentially infected) and releasing them in different locations where other tortoises live, this creates the direct contact mechanism required for disease transmission. This human transport system bypasses the tortoises' natural movement limitations while maintaining the direct contact requirement, explaining how disease could spread across widely separated areas.
The preferred habitat of gopher tortoises is ideally suited for growing citrus crops, but gopher tortoises cannot survive in areas planted with citrus trees.
This habitat information explains potential threats to tortoise populations but doesn't address how disease spreads between existing populations. The citrus crop issue relates to habitat loss, not disease transmission mechanisms, so it doesn't help explain the puzzling spread pattern.
The largest area currently inhabitated by gopher tortoises is a tract of land that is preserved by the national government.
Information about one large preserved area doesn't explain how disease spreads between the many widely separated areas mentioned in the passage. Even if this preserved area exists, we still need to explain how disease jumps between the scattered populations given the tortoises' limited movement range.
Gopher tortoises are generally inactive in cool weather and spend the winter months in a dormant state in their burrows.
Seasonal behavior patterns don't help explain disease transmission across geographic barriers. Whether tortoises are active or dormant doesn't change the fundamental problem that they don't travel far from their birthplace, so this doesn't provide a mechanism for disease spread between widely separated areas.