Darwin in his 'Natural Selection Theory' did not believe in any role of which one of the following in organic evolution

Options

A. Parasites and predators as natural enemies
B. Survival of the fittest
C. Struggle for existence
D. Discontinuous variations

Answer

To solve the question regarding Darwin's 'Natural Selection Theory' and what he did not believe played a role in organic evolution, we can follow these steps:

### Step 1: Understand Darwin's Theory of Natural Selection
Darwin's theory of natural selection is based on several key concepts:
- **Rapid Multiplication**: Organisms reproduce quickly, leading to a large population.
- **Limited Resources**: There is not enough food and space for all individuals to survive.
- **Variations**: There are differences among individuals in a population, which can be continuous or discontinuous.
- **Survival of the Fittest**: Only those individuals best adapted to their environment survive and reproduce.
- **Struggle for Existence**: There is competition among individuals for limited resources.

### Step 2: Analyze the Given Options
The question provides four options:
1. Parasites and predators are natural enemies.
2. Survival of the fittest.
3. Struggle for existence.
4. Discontinuous variations.

### Step 3: Identify What Darwin Did Not Believe
From the analysis of Darwin's theory:
- **Parasites and predators**: Darwin acknowledged the struggle between these organisms, indicating a role in natural selection.
- **Survival of the fittest**: This is a core concept of Darwin's theory.
- **Struggle for existence**: This is also a fundamental aspect of his theory.
- **Discontinuous variations**: Darwin primarily focused on continuous variations, which he believed were important for adaptation. He did not emphasize discontinuous variations in his theory.

### Conclusion
Based on the analysis, the correct answer is **discontinuous variations**. Darwin did not believe in the role of discontinuous variations in organic evolution as a significant factor in natural selection.

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