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Question #45205
The Question
According to Allen's Rule, mammals in colder climates typically possess shorter extremities to minimize heat loss. However, a specific sub-arctic mammalian predator exhibits unusually large pinnae and elongated limbs. Behavioral studies show it relies on prolonged, high-speed pursuits to capture prey. Which of the following eco-physiological trade-offs best explains this evolutionary deviation?
Options
- A.
The larger extremities decrease the surface area-to-volume ratio, thereby minimizing the metabolic cost of thermoregulation during rest.
- B.
Natural selection favored increased surface area for heat dissipation to prevent hyperthermia induced by the high metabolic demands of optimal foraging.
- C.
The predator exhibits phenotypic plasticity to conform to Bergmann’s rule, where larger extremities are required to support a larger body mass in colder latitudes.
- D.
The elongated limbs and large pinnae act as counter-current heat exchangers that maximize heat conservation during high-speed pursuits.
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Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Evolutionary_Exception
Tackle problems where standard rules evolve or change based on specific environmental constraints.
Concepts Behind This Question
Genetic Drift|Island Biogeography|Adaptive Radiation
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often rigidly apply Allen's Rule (Cold climate = Short extremities) without considering the physiological trade-offs of metabolic heat generation during intense physical activity.
The trap lies in treating ecological rules as absolute laws rather than evolutionary compromises that must balance basal thermoregulation against active metabolic demands (like preventing hyperthermia during optimal foraging).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Organisms and Populations - Class 12 |
| Concept | Allen’s Rule and Surface-to-Volume Ratio |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |