Which one of the following was not given by Darwin's theory of evolution

Options

A. Struggle for existence
B. Over production
C. natural selection
D. Genetic drift

Answer

To determine which option was not part of Darwin's theory of evolution, we can analyze each option in relation to Darwin's principles.

### Step-by-Step Solution:

1. **Understand Darwin's Theory of Evolution**:
- Darwin's theory primarily revolves around the concept of natural selection, which explains how species evolve over time through the survival and reproduction of individuals with favorable traits.

2. **Evaluate Each Option**:
- **Option 1: Struggle for Existence**:
- This concept is central to Darwin's theory. It refers to the competition among individuals for limited resources, which influences survival and reproduction.
- **Option 2: Overproduction**:
- Darwin also discussed overproduction, which refers to the tendency of species to produce more offspring than can survive. This leads to competition and natural selection.
- **Option 3: Natural Selection**:
- This is the cornerstone of Darwin's theory. It describes the process by which individuals with advantageous traits are more likely to survive and reproduce.
- **Option 4: Genetic Drift**:
- Genetic drift is a mechanism of evolution that involves random changes in allele frequencies in a population. This concept was introduced later and is not part of Darwin's original theory.

3. **Identify the Correct Answer**:
- Based on the evaluation, the option that was not given by Darwin's theory of evolution is **Option 4: Genetic Drift**.

### Final Answer:
**The correct answer is Option 4: Genetic Drift.**

---