The main drawback of Darwin's theory of natural selection was that it could not provide satisfactory explanation of

Options

A. Survival of fittest
B. Struggle for existence
C. Mimicry
D. Basis of variation and the mode of transmission of the variants to the next generation.

Answer

**Step-by-Step Solution:**

1. **Understanding Darwin's Theory of Natural Selection**:
- Darwin proposed that organisms that are best adapted to their environment are more likely to survive and reproduce. This concept is often summarized as "survival of the fittest."

2. **Identifying the Drawbacks**:
- While Darwin's theory explained how certain traits could lead to better survival, it did not adequately explain how these traits were passed on to the next generation.

3. **Evaluating Options**:
- The options provided include:
- Survival of the fittest
- Struggle for existence
- Mimicry
- Basis of Variation and Mode of Transmission of Variance to the next generation
- The first three options are integral parts of Darwin's theory and do not represent drawbacks.

4. **Focusing on Genetic Transmission**:
- The last option, "Basis of Variation and Mode of Transmission of Variance to the next generation," highlights a significant gap in Darwin's theory. Darwin did not have knowledge of genetics or DNA, which are crucial for understanding how traits are inherited.

5. **Conclusion**:
- The main drawback of Darwin's theory of natural selection is that it could not provide a satisfactory explanation of the basis of variation and how these variations are transmitted to the next generation.

**Final Answer**: The main drawback of Darwin's theory of natural selection was that it could not provide a satisfactory explanation of the basis of variation and mode of transmission of variance to the next generation.

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