Question

which environmental principle states that when two species occupy the same niche, one species will out - compete the other and ultimately one species will be excluded?
competitive exclusion principle
invasive species principle
native species principle

Explanation:

The Competitive Exclusion Principle states that two species cannot coexist in the same niche indefinitely. One will out - compete the other. Invasive Species Principle and Native Species Principle are not relevant to this specific ecological concept of niche competition and exclusion.

Answer:

Competitive Exclusion Principle