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. Normalisation
B. Genetic drift
C. Convergence
D. Divergence.

Answer

To answer the question about the common characteristics and conspicuous differences among whales, dolphins, bats, monkeys, and horses, we can break down the solution into the following steps:

### Step-by-Step Solution:

1. **Identify the Common Group**:
- All the mentioned animals (whales, dolphins, bats, monkeys, and horses) belong to the class Mammalia, which indicates they share certain fundamental characteristics typical of mammals, such as warm-bloodedness, hair/fur, and mammary glands.

**Hint**: Think about what defines a group of animals as mammals.

2. **Recognize the Common Ancestry**:
- These mammals share a common ancestor, which is a key aspect of evolutionary biology. This common ancestry means that they have evolved from a similar starting point.

**Hint**: Consider the concept of common ancestry in evolutionary terms.

3. **Understand the Differences**:
- Despite their common ancestry, these species exhibit significant differences in their physical structures, behaviors, and ecological roles. These differences arise from adaptations to their specific environments and lifestyles.

**Hint**: Reflect on how different environments can lead to different adaptations in species.

4. **Define Divergent Evolution**:
- The phenomenon that explains these differences is called divergent evolution. This occurs when species that share a common ancestor evolve and adapt to different environments, leading to variations over time.

**Hint**: Think about how species can evolve in different directions from a common point.

5. **Eliminate Incorrect Options**:
- The other options provided (normalization, genetic drift, and convergence) do not accurately describe the situation:
- **Normalization** refers to the process of organisms adapting to their environment but does not explain the origin of differences.
- **Genetic drift** is a random process affecting allele frequencies in small populations, not directly related to the evolution of distinct species from a common ancestor.
- **Convergence** refers to unrelated species developing similar traits due to similar environmental pressures, which is the opposite of what is being described here.

**Hint**: Consider the definitions of each term and how they relate to the concept of evolution.

6. **Conclusion**:
- Therefore, the correct answer to the question is that the conspicuous differences among these mammals are due to the phenomenon of **divergent evolution**.

### Final Answer:
The differences among whales, dolphins, bats, monkeys, and horses, despite their common characteristics as mammals, are due to the phenomenon of **divergent evolution**.