Competitive Exclusion Principle: Meaning, Types, Subtypes

The Principle of Competitive Exclusion, also called the Gause’s Law, states that two species cannot coexist if they are competing for the same resources.

• This principle was proposed by Georgy Gause. According to this principle, when there’s a fight over the same resources, one species is likely to drive off the other one.
• Though the second species might still survive as some of them might have adapted to the different niche.
• There are two different kinds of Competitive Exclusion seen in nature which includes Interspecific Competition, and Intraspecific Competition.

Key Takeaways: Competitive Exclusion Principle, Interspecific Competition, Intraspecific Competition, Interference, Exploitation

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What is the Competitive Exclusion Principle?

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The Principle of Competitive Exclusion, also called the Gause’s Law, states that two species cannot coexist if they are competing for the same resources. This principle was proposed by Georgy Gause. Although the principle is called Gause’s Law, Gause never actually formulated it. The principle is already found in Darwin’s Theory of Natural Selection.

According to this principle, when there’s a fight over the same resources, one species is likely to drive off the other one. Though the second species might still survive as some of them might have adapted to the different niche. Competitive Exclusion is a natural phenomenon, and it results in the evolution of organisms.

There are various examples of the Competitive Exclusion Principle in nature. Some of them are:

• An increase in the population of carnivores in a forest will result in food scarcity. The scarcity of food will result in competition among the animals. The stronger ones will win and dominate the weaker ones.
• Red Squirrels were replaced by Grey Squirrels in Britain. The population of red squirrels dwindled due to a shortage of hazelnuts, competitive exclusion, and diseases. Grey Squirrels adapted well to the change and gradually replaced the red squirrels.

Also Read: Charles Darwin Theory

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Types of Competitive Exclusion Principle

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The two types of Competition Exclusion Principle are as follows:

Interspecific Competition

When the competition takes place between the organisms of different species, it is called an Interspecific Competition. Examples of Interspecific Competition are Lions and Hyenas, oceans where some species of fish are the same prey for dolphins, sharks, and birds, etc.

Intraspecific Competition

When the competition takes place between organisms of the same species, it is called an Intraspecific Competition. An example of Intraspecific Competition is large and dominant grizzly bears that occupy the best fishing spots on a river.

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Sub-types of Competition

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The subtypes of Competition are as follows:

Interference

The direct flight between the organisms for resources is termed Interference. An example of Interference is the way animals protect their food from other animals.

Exploitation

When an organism consumes all the resources in an area, leaving no resources for the other animals, it is called Exploitation. It is, in a way, an indirect fight for resources.

Ecological Niche

Niche is the habitat in which a species thrives and the behavioural adaptations it accompanies. Every species has its ecological community and a certain number of environmental factors that it can tolerate to an extent. An example is that of a fish, its niche comprises factors like pH, temperature, water salinity, etc. The survival of two species becomes difficult if they have the same ecological niche.

Resource Partitioning

As mentioned above, the survival of two species becomes difficult if they have the same niche. But if these two species evolve to use different resources, their struggles can be avoided. This is called Resource Partitioning. It helps the species to coexist peacefully. An example of Resource Partitioning is the distribution of lizards in Puerto Rico.

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Things to Remember

Following are some important points:

• The Principle of Competitive Exclusion, also called the Gause’s Law, states that two species cannot coexist if they are competing for the same resources.
• Though the second species might still survive as some of them might have adapted to the different niche.
• When the competition takes place between the organisms of different species, it is called an Interspecific Competition. When the competition takes place between organisms of the same species, it is called an Intraspecific Competition.
• The direct fight between the organisms for resources is termed Interference. When an organism consumes all the resources in an area, leaving no resources for the other animals, it is called Exploitation.
• If two species with the same niche evolve to use different resources, their struggles can be avoided. This is called Resource Partitioning.