Q.State Gause's 'Competitive Exclusion Principle'. Give two examples of competition in nature. OR What is mutualism? Briefly explain mutualism with the wasp and fig plant interaction.

Avoiding competition by using the same resource differently is resource partitioning, shown by MacArthur; Gause's principle is competitive exclusion.

Two close ideas are often confused in the CBSE/NCERT Organisms and Populations chapter:

• Competitive exclusion (Gause's principle): two species competing for the same limiting resource cannot coexist indefinitely; the competitively inferior one is eliminated. …

Goats introduced to the Galápagos competed with native giant tortoises for the same vegetation, illustrating interspecific competition.

On the Galápagos (Abingdon/Pinta) island, goats were introduced by humans and rapidly multiplied, consuming large quantities of the same vegetation that the native Abingdon giant tortoises depended on for food. Since both species required the same limited food resource, and the presence of one (the fast-breeding, voracious goats) negatively impacted the survival/population of the other (the tortoises, whose numbers declined sharply, contributing to their eventual extinction on that is …

Five warbler species coexist through RESOURCE PARTITIONING, dividing up the tree so they do not compete directly.

By the competitive exclusion principle, two species competing for exactly the same limiting resource cannot coexist indefinitely. MacArthur's study of five closely related warbler species on the same tree showed how they avoid this:

…

'Competition' pairs with option (d) 'detrimental interaction' — because in competition, both interacting species are adversely affected.

In population ecology, interspecific interactions are classified by their effect (+, −, or 0) on each of the two interacting species: mutualism (+,+), commensalism (+,0), parasitism/predation (+,−), amensalism (−,0), and competition (−,−).

…

Allelopathy is due to secretion of toxins (allelochemicals).

Allelopathy is the phenomenon in which one plant releases chemical substances (allelochemicals/toxins) into the environment that inhibit the germination or growth of neighbouring plants of other species, reducing competition. A classic example is the inhibition of nearb …

Resource partitioning lets ecologically similar species avoid competitive exclusion by dividing up a shared resource.

According to the principle of competitive exclusion, two species competing for the exact same limiting resource cannot coexist indefinitely — one will eventually eliminate the other. Resource partitioning describes how, in nature, species that appear to compete for a resource often avoid actual competition by dividing that resource, for instance by feeding at different times of day, foraging at different heights or locations, or consuming slightly different types/sizes of food. MacArthur's study of five warbler species feeding on the same tree but in differen …