What is the Difference Between Competitive Exclusion and Resource Partitioning?

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The main difference between competitive exclusion and resource partitioning lies in how species interact with each other and their environment in order to coexist:

  • Competitive Exclusion: This principle states that two species cannot coexist if they occupy exactly the same niche (competing for identical resources). If species have identical niches, they would compete for the same resources, making it difficult for both species to survive. For example, when two species of single-celled microorganisms, Paramecium aurelia and Paramecium caudatum, were grown together in a lab with limited nutrients, P. aurelia eventually outcompeted P. caudatum for food, leading to its competitive exclusion.
  • Resource Partitioning: This is the division of limited resources by species to avoid interspecies competition. When two species differentiate their niches, they tend to compete less strongly, making it more likely for them to coexist. Resource partitioning can result in species evolving to use different resources, so there is no longer competition for that particular resource. For example, anole lizards on the island of Puerto Rico have evolved different species that make use of different resources, allowing them to coexist.

In summary, competitive exclusion refers to the idea that species with identical niches cannot coexist, while resource partitioning is the process by which species diversify their niches to avoid direct competition and coexist more effectively.

Comparative Table: Competitive Exclusion vs Resource Partitioning

Competitive exclusion and resource partitioning are two concepts that describe how species interact with each other in relation to their resources and habitat. Here is a table summarizing the differences between the two concepts:

Feature Competitive Exclusion Resource Partitioning
Definition The principle stating that two species cannot occupy the exact same niche in a habitat, as they would compete for the same resources and one would be eliminated. The division of limited resources by species to avoid competition, allowing them to coexist in the same habitat.
Occurrence Occurs when two species have identical niches and compete for the same resources, leading to the extinction of one species. Occurs when species with overlapping niches evolve to use different resources, occupy different areas, or feed at different times, allowing them to coexist.
Examples Paramecium aurelia and Paramecium caudatum: When grown together in a test tube with limited nutrients, P. aurelia outcompetes P. caudatum, leading to its extinction. Different species of bumblebees in the mountains of Colorado, where individuals of the same species show a high degree of overlap in resource use, but species as a whole have differentiated resource use.

In summary, competitive exclusion refers to the idea that two species cannot coexist with the same niche, as they would compete for the same resources and one would eventually be eliminated. Resource partitioning, on the other hand, is the division of limited resources by species to avoid competition, allowing them to coexist in the same habitat.