New species are evolved due to cumulative effect of fluctuating variations according to

Options

A. Natural selection theory
B. Mutation theory
C. Lamarckism
D. Neolamarckism

Answer

**Step-by-Step Text Solution:**

1. **Understanding the Question**: The question asks which theory states that new species evolve due to the cumulative effect of fluctuating variations.

2. **Identifying the Theories**: The options provided are:
- Natural Selection Theory
- Mutation Theory
- Lamarquism
- Neolamarquism

3. **Analyzing Each Theory**:
- **Natural Selection Theory**: This theory, proposed by Charles Darwin, suggests that individuals with heritable traits that are better suited to their environment are more likely to survive and reproduce. It does not specifically emphasize fluctuating variations leading to new species.
- **Mutation Theory**: This theory focuses on mutations as the primary driver of evolution. It does not emphasize the cumulative effect of fluctuating variations.
- **Lamarquism**: Proposed by Jean-Baptiste Lamarck in 1809, this theory suggests that organisms evolve through the inheritance of acquired characteristics. It posits that changes in the environment create new needs for organisms, leading them to develop new structures, which are then inherited by future generations.
- **Neolamarquism**: This theory builds on Lamarck's ideas but emphasizes adaptations affecting somatic cells rather than germline cells. It also does not focus on fluctuating variations.

4. **Selecting the Correct Answer**: Based on the analysis, Lamarquism is the correct answer. It explains that new species evolve due to the cumulative effect of fluctuating variations through the inheritance of acquired characteristics.

5. **Conclusion**: The correct answer to the question is **Lamarquism**.

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