Which of the following is not under Darwin's theory of natural selection ?

Options

A. Over production
B. Survival of fittest
C. Causes of variation
D. Struggle for existence

Answer

To determine which of the following options is not under Darwin's theory of natural selection, we need to analyze the key components of Darwin's theory. Here’s a step-by-step breakdown of the reasoning:

### Step 1: Understand the Key Components of Natural Selection
Darwin's theory of natural selection includes several fundamental concepts:
- **Variation**: There must be differences among individuals in a population.
- **Inheritance**: Traits that confer advantages must be heritable.
- **Overproduction**: Organisms tend to produce more offspring than can survive.
- **Struggle for Existence**: Individuals must compete for limited resources.
- **Survival of the Fittest**: Those with advantageous traits are more likely to survive and reproduce.

### Step 2: Analyze the Options
Now, let's evaluate the options provided in the question:
1. **Overproduction**: This is a key component of Darwin's theory, as it relates to the idea that more offspring are produced than can survive.
2. **Survival of the Fittest**: This is also a fundamental aspect of natural selection, emphasizing that individuals best suited to their environment are more likely to survive.
3. **Cause of Variation**: While variation is essential for natural selection, Darwin did not explain the origin of variation (e.g., mutations). This aspect is often considered outside the scope of his original theory.
4. **Struggle for Existence**: This concept is integral to natural selection, as it describes the competition among individuals for resources.

### Step 3: Identify the Correct Answer
From the analysis, the option that is not under Darwin's theory of natural selection is:
- **Cause of Variation**: Darwin acknowledged variation but did not explain its origins.

### Final Answer
The answer is **Cause of Variation**.

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