Which type of natural selection in a population is rare in occurrence than others ?

Options

A. Directional selection
B. Disruptive selection
C. Stabilizing selection
D. Balancing selection

Answer

To determine which type of natural selection is rare in occurrence compared to others, we will analyze the different types of natural selection: directional selection, disruptive selection, stabilizing selection, and balancing selection.

### Step-by-Step Solution:

1. **Understanding Natural Selection**:
- Natural selection is a process where organisms better adapted to their environment tend to survive and produce more offspring. This concept is central to Darwin's theory of evolution.

2. **Types of Natural Selection**:
- There are three main types of natural selection:
- **Directional Selection**: This occurs when individuals at one extreme of a trait distribution have higher fitness. The peak of the trait distribution shifts in one direction.
- **Disruptive Selection**: This type of selection favors individuals at both extremes of the trait distribution, leading to the formation of two distinct peaks.
- **Stabilizing Selection**: This occurs when individuals with intermediate traits have higher fitness, resulting in a narrower peak around the average trait.

3. **Analyzing Each Type**:
- **Directional Selection**: Commonly observed in populations adapting to changing environments.
- **Stabilizing Selection**: Frequently occurs as it supports the average phenotype, reducing variation.
- **Disruptive Selection**: Rarely observed because it requires specific environmental conditions that favor both extremes while not supporting the intermediate phenotype.

4. **Conclusion**:
- Among the types of natural selection discussed, **disruptive selection** is the rarest because it leads to the formation of two distinct groups and is less common in stable environments where intermediate traits are often favored.

### Final Answer:
The type of natural selection that is rare in occurrence compared to others is **Disruptive Selection**.