The principle of competitive exclusion states that
a. Two species cannot coexist in the same habitat.
b. Competition between two species always causes extinction or emigration of one species.
c. Two species that have exactly the same niche cannot coexist in a community.
d. Two species will stop reproducing until one species leaves the habitat.

Verified step by step guidance

1. Understand the principle of competitive exclusion, which is a concept in ecology that describes the outcome when two species compete for the same resources.
2. Recognize that the principle is based on the idea that two species cannot occupy the same niche in a community if they are competing for identical resources.
3. Consider the implications of this principle: if two species have identical niches, one will outcompete the other, leading to the exclusion of the less competitive species.
4. Evaluate the options given in the problem: a) two species cannot coexist in the same habitat, b) competition between two species always causes extinction or emigration of one species, c) two species that have exactly the same niche cannot coexist in a community, d) two species will stop reproducing until one species leaves the habitat.
5. Identify the option that aligns with the principle of competitive exclusion, which is that two species with exactly the same niche cannot coexist in a community, as one will outcompete the other.

Key Concepts

Competitive Exclusion Principle

The competitive exclusion principle, also known as Gause's Law, posits that two species competing for the exact same resources cannot stably coexist. If two species have identical niches, one will outcompete the other, leading to the latter's extinction or emigration. This principle highlights the importance of niche differentiation in maintaining biodiversity.

Ecological Niche

An ecological niche refers to the role and position a species has in its environment, including all its interactions with biotic and abiotic factors. It encompasses how a species obtains resources, its behavior, and its contribution to the ecosystem. Understanding niches is crucial for grasping how species coexist and compete within communities.

Species Coexistence

Species coexistence involves multiple species living together in the same habitat without one driving the other to extinction. This is possible when species have different niches or when resources are abundant enough to reduce competition. Mechanisms like resource partitioning and temporal separation facilitate coexistence, allowing biodiversity to flourish.