Organisms and Populations Question 42

42. Gause’s principle of competitive exclusion states that :

[2016]

(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.

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Answer : c

Hints & Solutions

(c) Gause’s principle of competitive exclusion can be restated to say that no two species can occupy the same niche indefinitely when resources are limiting. Certainly species can and do coexist while competing for some of the same resources. Nevertheless, Gause’s theory predicts that when two species coexist on a long-term basis, either resources must not be limited or their niches will always differ in one or more features; otherwise, one species will outcompete the other and the extinction of the second species will inevitably result, a process referred to as competitive exclusion. The Abingdon tortoise in Galapagos Islands became extinct within a decade after goats were introduced on the island, apparently due to the greater browsing efficiency of the goats.