Which of the following is key concept of Darwin theory of evolution?

Options

A. Branching descent
B. Use and disuse of organ
C. Natural selection
D. Both (1) and (2)

Answer

To answer the question regarding the key concepts of Darwin's theory of evolution, we can break down the solution into several steps:

### Step-by-Step Solution:

1. **Understanding Darwin's Theory of Evolution**:
- Darwin's theory primarily focuses on how species evolve over time through natural processes.

2. **Identifying Key Concepts**:
- Two major concepts are integral to Darwin's theory:
- **Branching Descent**: This concept explains how species diverge from common ancestors over generations.
- **Natural Selection**: This principle states that organisms with traits better suited to their environment are more likely to survive and reproduce, passing those advantageous traits to the next generation.

3. **Evaluating the Options**:
- The question presents several options regarding the key concepts of Darwin's theory.
- Option 1 refers to branching descent, and Option 3 refers to natural selection.

4. **Determining the Correct Answer**:
- Since both branching descent and natural selection are fundamental to Darwin's theory, the correct option would be the one that includes both concepts.
- Therefore, the correct answer is Option 4: both 1 and 3.

5. **Clarifying Misconceptions**:
- Option 2 mentions the "use and disuse of organs," which is a concept proposed by Lamarck, not Darwin. This theory was later rejected as it was found that acquired characteristics are not inherited.

### Final Answer:
The key concepts of Darwin's theory of evolution include both branching descent and natural selection. Therefore, the correct answer is Option 4: both 1 and 3.

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