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

Options

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

Explanation

To solve the question, "Darwin in his 'Natural Selection Theory' did not believe in any role of which one of the following in organic evolution," we will analyze the options provided and understand the principles of Darwin's theory of natural selection.

### Step-by-Step Solution:

1. **Understand Natural Selection Theory**:
- Darwin's theory of natural selection is based on the idea that organisms produce more offspring than can survive. This leads to competition for resources, resulting in a "struggle for existence."

2. **Identify Key Concepts of Natural Selection**:
- **Survival of the Fittest**: This concept means that individuals with advantageous traits are more likely to survive and reproduce.
- **Variation**: Darwin acknowledged that there are variations among individuals in a population, which can be inherited.

3. **Analyze Each Option**:
- **Option 1: Discontinuous Variations**: These are large, sudden changes (like mutations) that do not fit into the gradual process of evolution that Darwin proposed. Darwin did not emphasize these in his theory.
- **Option 2: Parasites and Predators as Natural Enemies**: Darwin recognized that these play a role in natural selection by creating competition and influencing survival.
- **Option 3: Survival of the Fittest**: This is a core principle of Darwin's theory.
- **Option 4: Struggle for Existence**: This is also a fundamental aspect of Darwin's theory, highlighting the competition for limited resources.

4. **Determine the Correct Answer**:
- Since Darwin did not believe in the role of discontinuous variations in organic evolution, the correct answer is **Option 1: Discontinuous Variations**.

### Conclusion:
Darwin in his 'Natural Selection Theory' did not believe in any role of **discontinuous variations** in organic evolution.

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