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Question #46087
The Question
A critically endangered mammalian species is bred in a zoo (ex-situ) and a small group is subsequently reintroduced into a highly fragmented, small-area sanctuary (in-situ). Despite abundant resources and no predators, the population crashes within a few generations. Synthesizing population genetics with the species-area relationship (S = CA^Z), which of the following best explains this failure?
Options
- A.
The small area of the sanctuary restricted carrying capacity, which, combined with the founder effect from the captive population, accelerated genetic drift and inbreeding depression.
- B.
The fragmented sanctuary exhibited a Z-value of 1.15, which inherently favors high extinction rates and competitive exclusion for reintroduced captive species.
- C.
Ex-situ captive breeding induced a high degree of heterozygosity, which was rapidly selected against by the stabilizing selection of the in-situ habitat.
- D.
The low Z-value of the small sanctuary triggered rapid adaptive radiation, causing the reintroduced species to undergo sympatric speciation and reproductive isolation.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Comparative_Analysis
Sharpen your ability to evaluate multiple scenarios and distinguish between competing potential answers.
Concepts Behind This Question
Sacred Groves as Refugia|Ecotone and Edge Effect|Z-value in Large Areas
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Integrating Ecology (Species-Area Relationship) with Evolution (Population Genetics).
Students often fail to connect that a small geographical area enforces a small population size, which mathematically amplifies genetic drift and inbreeding depression, especially in populations already suffering from a captive bottleneck.
The trap in Option B tests the quantitative nuance of the Z-value from NCERT, where 1.15-1.2 applies only to massive continental areas.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Biodiversity and Conservation - Class 12 |
| Concept | Sacred Groves as Refugia |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |