Question

Gause’s principle of competitive exclusion states that
A. More abundant species will exclude the less abundant species through competition.
B. Competition for the same resources excludes species having different food preferences.
C. No two species can occupy the same niche indefinitely for the same limiting resources.
D. Larger organisms exclude smaller ones through competition.

Answer 1

Hint: In Georgy Gause experiment, Paramecium aurelia and Paramecium caudatum thrive well independently, but P. aurelia outcompetes P. caudatum as they fight for the same resources.

Complete Answer:
Based on laboratory competitiveness studies using two types of Paramecium species, P. aurelia and P. caudatum, Georgy Gause proposed the law of competitive exclusion. The specifications were to provide fresh water every day and provide a steady supply of food. While P. caudatum initially dominated, by exploitative resource competition, but P. aurelia survived and eventually drove P. caudatum extinct. However, by varying the environmental parameters (food, water), Gause was able to help P. caudatum live. Therefore, Gause’s rule is only true if the ecological variables are stable.

Now, let us find the solution from the options-
- The theory of competitive exclusion also referred to as the Competitive Exclusion Law of Gause or just the Law of Gause, states that two animals that compete over the very same resources are unable to coexist stably.
- In the long term or an evolutionary change of the weaker competitor into a particular ecological niche, one of the two competitors will still have an ever so small advantage over the other that leads to the disappearance of the second competitor. As a result, in environments where they all coexist, competing associated species also establish distinguishing characteristics.

Thus, the correct answer is option C, No two species can occupy the same niche indefinitely for the same limiting resources.

Note: Georgii Gause is classically attributed to the theory of competitive exclusion, although he never actually proposed it. In Darwin's theory of natural selection, the idea is already present. The state of the theory has oscillated throughout its history between a priori ('two coexisting species should have distinct niches') and experimental reality ('we notice that coexisting species have distinct niches').