Allen's rule is related to -

Options

A. Hibernation
B. Aestivation
C. Migration
D. Evolution

Answer

**Step-by-Step Solution:**

1. **Understanding Allen's Rule**: Allen's Rule states that mammals living in colder climates tend to have shorter limbs and ears compared to those in warmer climates. This adaptation helps reduce heat loss.

2. **Reason for Short Limbs and Ears**: The primary reason for this adaptation is that heat loss is a function of surface area. Shorter limbs and ears mean a smaller surface area, which helps retain body heat.

3. **Thermal Regulation**: Maintaining body temperature is crucial for survival, especially in cold environments. The process of thermal regulation requires energy, so adaptations that minimize heat loss are beneficial.

4. **Evolutionary Perspective**: Over time, through the process of evolution, mammals in colder regions have developed these physical traits as a means of survival. This gradual change in body structure is a result of natural selection.

5. **Elimination of Other Options**:
- **Hibernation**: This is a state of reduced metabolic activity during cold conditions, not directly related to physical adaptations.
- **Estivation**: Similar to hibernation but occurs in hot conditions; again, not related to Allen's Rule.
- **Migration**: This involves moving to different areas to escape unfavorable conditions, not a physical adaptation.

6. **Conclusion**: Allen's Rule is related to evolution, specifically how certain traits develop over time in response to environmental pressures.

**Final Answer**: Allen's rule is related to evolution.

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