Ear lobes of Arctic Fox are smaller than that of tropical Fox. This is

Options

A. Jordan's Rule
B. Bergman's Rule
C. Allen's Rule
D. Gloger's Rule

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question states that the ear lobes of Arctic Fox are smaller than those of the tropical Fox. We need to identify the biological principle that explains this observation.

2. **Identifying the Options**: The options provided are:
- Jordan's Rule
- Bergmann's Rule
- Allen's Rule
- Gloger's Rule

3. **Analyzing Each Rule**:
- **Jordan's Rule**: This rule refers to the relationship between water temperature and the number of vertebrae in fish. It does not apply to the size of ear lobes in foxes.
- **Bergmann's Rule**: This rule states that larger body sizes are found in colder environments, while smaller sizes are found in warmer regions. This rule pertains to overall body size rather than specific appendages like ear lobes.
- **Gloger's Rule**: This rule suggests that animals in humid environments tend to have darker pigmentation. It does not relate to ear lobe size or appendage length.
- **Allen's Rule**: This rule states that animals in colder climates tend to have shorter appendages (like limbs and ears) compared to those in warmer climates. This directly relates to the observation about the Arctic Fox.

4. **Conclusion**: Since the ear lobes of the Arctic Fox are smaller due to its adaptation to a colder climate, the correct answer is **Allen's Rule**.

### Final Answer:
The ear lobes of Arctic Fox being smaller than those of tropical Fox is explained by **Allen's Rule**.

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