In a random mating population in equilibrium, which of the following brings about a change in gene frequency in a non-directional manner?

Options

A. Migration
B. Mutation
C. Random drift
D. Selection

Explanation

To solve the question regarding which factor brings about a change in gene frequency in a non-directional manner in a random mating population in equilibrium, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Random Mating and Equilibrium**:
- Random mating refers to a situation where individuals of one sex have an equal chance of mating with individuals of the opposite sex. This is a key assumption of the Hardy-Weinberg equilibrium, which states that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences.

2. **Identify Factors Affecting Gene Frequency**:
- In a population, several factors can affect gene frequencies, including natural selection, genetic drift, mutation, migration, and non-random mating. However, the question specifically asks for a non-directional change.

3. **Define Non-Directional Change**:
- Non-directional change means that the change does not favor one allele over another; it does not push the population in a specific direction. Instead, it introduces variability without a consistent trend.

4. **Analyze the Role of Mutations**:
- Mutations are random changes in the genetic material. They occur spontaneously and can introduce new alleles into a population. Since mutations happen randomly and do not favor any specific allele, they can lead to changes in gene frequency in a non-directional manner.

5. **Conclusion**:
- Among the various factors, mutations are the only ones that can change gene frequencies in a non-directional manner in a random mating population in equilibrium. Therefore, the correct answer is mutations.

### Final Answer:
Mutations bring about a change in gene frequency in a non-directional manner in a random mating population in equilibrium.

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