Being all mammals, whale, dolphins, bat, monkey and horse have some common character but they also show conspicuous differences. This is due to phenomenon of

Options

A. Divergence
B. Convergence
C. Genetic drift
D. Normalization

Answer

To solve the question regarding the common characteristics and conspicuous differences among mammals such as whales, dolphins, bats, monkeys, and horses, we need to understand the concepts of evolution, particularly divergence and convergence.

### Step-by-Step Solution:

1. **Identify the Common Characteristics**:
- All the mentioned animals (whales, dolphins, bats, monkeys, and horses) are mammals. This means they share certain common traits such as mammary glands, hair/fur, and three middle ear bones.

2. **Recognize the Differences**:
- Despite their common characteristics, these mammals exhibit significant differences in their physical structures, behaviors, and adaptations to their environments. For example, whales and dolphins are adapted to aquatic life, while bats are adapted for flight.

3. **Understand the Concept of Divergence**:
- Divergence refers to the process by which related organisms develop different traits as they adapt to different environments or ecological niches. This leads to the formation of homologous structures, which are similar in origin but may serve different functions.

4. **Differentiate from Convergence**:
- In contrast, convergence occurs when unrelated organisms develop similar traits due to adapting to similar environments, resulting in analogous structures. This is not the case here since we are discussing mammals that share a common ancestry.

5. **Evaluate Other Options**:
- Genetic drift refers to random changes in allele frequencies in a population, which does not directly explain the observed differences among these mammals. Normalization is not a recognized evolutionary phenomenon in this context.

6. **Conclusion**:
- The conspicuous differences among these mammals, despite their common characteristics, are primarily due to the phenomenon of divergence.

### Final Answer:
The correct answer is **A: Divergence**.

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