Robert may estimated the total number of species of the world at

Options

A. 1.5 million
B. 30 million
C. 33 million
D. 7 million

Answer

To solve the question regarding Robert May's estimation of the total number of species in the world, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Scientist and Context**: Recognize that Robert May is a prominent scientist known for his contributions to ecology and biodiversity.

**Hint**: Think about the contributions of scientists in ecology and their estimates regarding biodiversity.

2. **Recall the Year of Estimation**: Note that Robert May made his estimation in the year 1954.

**Hint**: Consider the historical context of scientific estimates and when they were made.

3. **Understand the Estimated Number**: According to Robert May, he estimated that there are approximately 7 million species in the world.

**Hint**: Focus on the specific number mentioned in the question and how it relates to the total biodiversity.

4. **Acknowledge the Current Understanding**: While Robert May estimated 7 million species, it is understood that the actual number may be higher, with estimates suggesting around 9 million species have been identified.

**Hint**: Be aware of how scientific estimates can evolve over time with new discoveries.

5. **Select the Correct Answer**: Based on the information provided, the correct answer to the question is that Robert May estimated the total number of species in the world at 7 million.

**Hint**: Look for the answer that directly corresponds to Robert May's estimation in the context of the question.

### Final Answer:
Robert May estimated the total number of species of the world at approximately **7 million**.