Who among the following is not a naturalist?

Options

A. Darwin
B. Malthus
C. Wallace
D. All of the above

Answer

To determine who among the following is not a naturalist, we will analyze the contributions of each individual mentioned in the question: Charles Darwin, Thomas Malthus, and Alfred Russel Wallace.

### Step-by-Step Solution:

1. **Understanding the term "Naturalist":**
- A naturalist is a person who studies or is an expert in natural history, particularly in the observation and study of plants, animals, and the environment.

2. **Analyzing Charles Darwin:**
- Charles Darwin is known for his theory of evolution through natural selection. He studied various species and their adaptations to the environment, which aligns with the definition of a naturalist.
- Conclusion: **Darwin is a naturalist.**

3. **Analyzing Thomas Malthus:**
- Thomas Malthus is known for his work on population growth and the Malthusian theory, which states that population growth will outpace food supply growth, leading to societal issues like famine and disease.
- Malthus did not primarily focus on the study of natural history or the observation of species.
- Conclusion: **Malthus is not a naturalist.**

4. **Analyzing Alfred Russel Wallace:**
- Alfred Russel Wallace is also recognized as a naturalist who independently proposed the theory of evolution through natural selection alongside Darwin. He conducted extensive studies on biodiversity and biogeography.
- Conclusion: **Wallace is a naturalist.**

5. **Final Conclusion:**
- Among the individuals listed, Thomas Malthus is the one who is not a naturalist.

### Answer:
**Thomas Malthus is not a naturalist.**

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