Question

According to the principle of competitive exclusion

• A. Two species cannot coexist-in the same habitat
• B. Extinction or emigration are the only possible results of competitive interactions
• C. Intraspecific competition results in the success of the best-adapted individuals
• D. Two species cannot share the same realized niche in a habitat

Answer 1

The correct option is D Two species cannot share the same realized niche in a habitat

The competitive exclusion principle states that two species competing for the same limiting resource cannot coexist at constant population values. When one species has even the slightest advantage over another, the one with the advantage will dominate in the long term. This leads either to the extinction of the weaker competitor or to an evolutionary or behavioral shift toward a different ecological niche. Competitive exclusion is rarely observed in natural ecosystems.

So the correct option is 'two species cannot share the same realized niche in a habitat'.