Question

Explain Gause’s 'Competitive Exclusion Principle' and provide a suitable ecological example that demonstrates this principle in nature.

Hint:

Gause's principle applies when resources are limited. If resources are abundant, species can coexist without direct conflict. When resources are scarce, competition can lead to niche differentiation or the exclusion of the less competitive species.

Answer 1

Concept: In community ecology, interspecific competition plays an important role in shaping population dynamics and species distribution. Gause's Competitive Exclusion Principle describes what happens when two closely related species compete for the same limited resources.

Step 1: Stating the formal Core Principle.
Gause's Competitive Exclusion Principle states that two closely related species competing for identical, limited environmental resources cannot coexist indefinitely within the same ecological niche.
• This occurs because the species that is even slightly better at gathering resources will outcompete the other.
• The less competitive species will either experience a population decline, adapt by shifting its ecological niche, or eventually face local extinction.

Step 2: Analyzing a classic ecological example.
A well-documented example of this principle occurred when Abingdon tortoises were introduced to the Galapagos Islands along with domestic goats:
• Both the tortoises and the goats fed on the same limited vegetation across the islands.
• The introduced goats were much faster and more efficient browsers, quickly consuming the available food plants.
• Because the tortoises were slower and less efficient at feeding, they could not get enough nourishment. Within a decade of introducing the goats, the Abingdon tortoises became extinct on the island due to intense resource competition.