Which is not true for genetic drift?

Options

A. It is the change in gene frequency by chance
B. It operates rapidly in large population
C. It can happened due to habitat fragmentation
D. It is also known as Sewall-Wright effect

Answer

To determine which statement is not true for genetic drift, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Understanding Genetic Drift**:
- Genetic drift is a mechanism of evolution that involves changes in allele frequencies within a population due to random sampling of organisms. This means that allele frequencies can fluctuate from one generation to the next purely by chance.

2. **Analyzing the Options**:
- **Option 1**: "It is a change in gene frequency by chance."
- This statement is true. Genetic drift indeed causes changes in gene frequencies due to random events.

- **Option 2**: "It operates rapidly in large populations."
- This statement is **not true**. Genetic drift has a more pronounced effect in small populations because random events can significantly alter allele frequencies when there are fewer individuals.

- **Option 3**: "It can happen due to habitat fragmentation."
- This statement is true. Habitat fragmentation can lead to smaller, isolated populations, which can experience genetic drift.

- **Option 4**: "It is also known as the Sewall Wright effect."
- This statement is true. The Sewall Wright effect refers to the phenomenon of genetic drift, named after the geneticist Sewall Wright.

3. **Conclusion**:
- The statement that is not true for genetic drift is: **"It operates rapidly in large populations."** Genetic drift operates more rapidly in small populations.

### Final Answer:
The statement that is not true for genetic drift is: **"It operates rapidly in large populations."**

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