Which statement explains why two species cannot permanently occupy the same ecological niche?

Options

A. The two species could not interbreed
B. The two species may be part of separate food webs
C. The two species would compete for the same resources
D. The two species would have different nutritional requirements.

Answer

To answer the question "Which statement explains why two species cannot permanently occupy the same ecological niche?", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Concept of Ecological Niche**:
- An ecological niche refers to the role and position a species has in its environment, including all its interactions with biotic and abiotic factors. It encompasses how a species obtains its resources, how it survives, and how it interacts with other species.

2. **Introducing the Competitive Exclusion Principle**:
- The Competitive Exclusion Principle, proposed by Gause, states that two species competing for the same limited resources cannot coexist indefinitely. One species will outcompete the other, leading to the exclusion of the less competitive species.

3. **Analyzing the Options**:
- **Option 1**: "Two species could not interbreed." - This is not directly related to the concept of ecological niches.
- **Option 2**: "The two species may be part of separate food webs." - This does not address competition for resources.
- **Option 3**: "The two species would compete for the same resources." - This aligns with the Competitive Exclusion Principle, indicating that competition for limited resources is a key reason they cannot coexist.
- **Option 4**: "The two species would have different nutritional requirements." - This suggests they could coexist if their nutritional needs differ, which contradicts the premise of the question.

4. **Selecting the Correct Answer**:
- Based on the analysis, **Option 3** is the correct answer: "The two species would compete for the same resources." This explains why two species cannot permanently occupy the same ecological niche, as competition for limited resources leads to the exclusion of one species.

### Final Answer:
The correct statement that explains why two species cannot permanently occupy the same ecological niche is: **"The two species would compete for the same resources."**

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