According to Allen's Rule, the mammals from colder climates have

Options

A. shorter ears and longer limbs
B. longer ears and shorter limbs
C. longer ears and longer limbs
D. shorter ears and shorter limbs

Explanation

**Step-by-Step Solution:**

1. **Understanding Allen's Rule**: Allen's Rule states that animals living in colder climates tend to have shorter appendages (like ears and limbs) compared to those in warmer climates. This adaptation helps minimize heat loss.

2. **Homeostasis and Thermoregulation**: Mammals are warm-blooded animals capable of maintaining a constant internal body temperature, a process known as thermoregulation. This ability allows them to survive in varying environmental conditions.

3. **Energy Considerations**: Maintaining a constant internal environment, especially in extreme cold, requires energy. If mammals have longer extremities, they have a larger surface area, leading to increased heat loss, which makes thermoregulation energetically expensive.

4. **Body Size and Surface Area**: In colder climates, larger body size is advantageous because it reduces the surface area-to-volume ratio, thereby minimizing heat loss. Shorter limbs and ears help retain body heat.

5. **Conclusion**: According to Allen's Rule, mammals from colder climates typically have shorter ears and limbs. This adaptation helps them conserve body heat and maintain a stable internal environment despite low external temperatures.

**Final Answer**: According to Allen's Rule, mammals from colder climates have shorter ears and shorter limbs.

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