Adaptive radiation refers to

Options

A. adaptations due to geographical isolation
B. evolution of different species from a common ancestor
C. migration of members of a species to different geographical areas
D. power of adaptation in an individual to a variety of environments

Explanation

**Step-by-Step Solution:**

1. **Understanding Adaptive Radiation**:
- Adaptive radiation is a process where a single ancestral species evolves into a variety of forms to adapt to different environments. This process is also known as divergent evolution.

2. **Mechanism of Adaptive Radiation**:
- As the original population of a species increases, it spreads out from its center of origin. This expansion allows the species to exploit new habitats and food sources.

3. **Formation of New Species**:
- Over time, as populations adapt to their specific environments, they can diverge significantly from one another, leading to the formation of new species.

4. **Example of Adaptive Radiation**:
- A classic example is the Australian marsupials, which have adapted to various habitats and evolved into different forms such as carnivores, herbivores, burrowers, and flyers.

5. **Evaluating the Options**:
- The question presents four options regarding what adaptive radiation refers to.
- **Option 1**: Adaptations due to geographical isolation - This is correct as geographical isolation can lead to adaptive radiation.
- **Option 2**: Evolution of different species from a common ancestor - This is a general statement about evolution but does not specifically define adaptive radiation.
- **Option 3**: Migration of members of a species to different geographical areas - This is incorrect as adaptive radiation is more about isolation rather than migration.
- **Option 4**: Power of adaptation in an individual to a variety of environments - This is also incorrect as adaptive radiation refers to populations, not individual adaptations.

6. **Conclusion**:
- The correct answer to the question is "adaptations due to geographical isolation."

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