Convergent evolution is illustrated by

Options

A. Rat and dog
B. Bacterium and protozoan
C. Satr fish and cuttlefish
D. Dog fish and whale

Answer

### Step-by-Step Solution:

1. **Understand Convergent Evolution**:
- Convergent evolution occurs when different species evolve similar traits or functions due to similar environmental conditions, despite having different ancestral origins. This results in analogous structures rather than homologous structures.

2. **Analyze the Options**:
- **Option A: Rat and Dog**: Both are mammals and share a common ancestor. They do not illustrate convergent evolution.
- **Option B: Bacterium and Protozoan**: Bacteria and protozoans belong to different domains (prokaryotes vs. eukaryotes), but bacteria are not a type of protozoan. This option does not illustrate convergent evolution.
- **Option C: Starfish and Cuttlefish**: Starfish (echinoderms) and cuttlefish (mollusks) are from different phyla. However, they do not exhibit similar morphological or functional characteristics that would indicate convergent evolution.
- **Option D: Dogfish and Whale**: Dogfish (a type of shark) and whale (a mammal) are both adapted to aquatic life but belong to different classes (fish vs. mammal). They have evolved similar adaptations for living in water, demonstrating convergent evolution.

3. **Identify the Correct Answer**:
- The correct answer is **Dogfish and Whale**. They illustrate convergent evolution due to their similar adaptations to an aquatic environment despite their different evolutionary backgrounds.