Which one of the following scientists is not related with organic evolution ?

Options

A. (a) T.R.Malthus
B. (b) Erasmus Darwin
C. (c) Darlington
D. (d) Charles Darwin

Answer

To determine which scientist is not related to organic evolution, we will analyze the contributions of each scientist mentioned in the options.

### Step-by-Step Solution:

1. **Identify the Scientists**: The question provides four scientists: T. R. Malthus, Erasmus Darwin, Darlington, and Charles Darwin.

2. **Analyze T. R. Malthus**:
- T. R. Malthus is known for his theory on population growth. He proposed that populations grow exponentially while resources grow arithmetically, leading to competition for limited resources.
- **Relation to Organic Evolution**: His ideas influenced evolutionary thought by highlighting the struggle for existence, which is a key concept in natural selection.

3. **Analyze Erasmus Darwin**:
- Erasmus Darwin, the grandfather of Charles Darwin, proposed ideas about the evolution of species and the concept of common descent in his writings.
- **Relation to Organic Evolution**: He is directly related to the study of organic evolution through his theories on the transformation of species.

4. **Analyze Darlington**:
- Darlington is known for his work in genetics, particularly chromosomal crossover and genetic variation.
- **Relation to Organic Evolution**: While genetics is important for understanding evolution, Darlington’s focus on chromosomal crossover does not directly relate to the concept of organic evolution as it pertains to speciation.

5. **Analyze Charles Darwin**:
- Charles Darwin is famous for his theory of natural selection, which is a fundamental concept in the study of evolution.
- **Relation to Organic Evolution**: He is one of the key figures in organic evolution, providing a mechanism for how evolution occurs.

6. **Conclusion**:
- After analyzing the contributions of each scientist, it is clear that T. R. Malthus, Erasmus Darwin, and Charles Darwin all have significant connections to organic evolution.
- Darlington, however, is primarily associated with genetics and does not directly contribute to the concept of organic evolution.
- Therefore, the scientist not related to organic evolution is **C. Darlington**.

### Final Answer:
C. Darlington