What is the key difference between a dominant species and a keystone species?

• A. There is no difference. The two terms are synonymous.
• B. Dominant species alter the structure or dynamics of the environment; keystone species are the most abundant.
• C. The removal of a dominant species from a community has more impact than removing a keystone species.
• D. Keystone species are more successful at evading their predators and the impacts of disease.
• E. Dominant species are the most abundant; keystone species exert control through important roles or niches.

Answer: (E)

Verified step by step guidance

1. Understand the definitions: A dominant species is one that is the most abundant or has the highest biomass in a community. A keystone species, on the other hand, is not necessarily abundant but plays a critical role in maintaining the structure of an ecological community.
2. Consider the ecological impact: Dominant species have a significant impact due to their abundance, which can affect the availability of resources for other species. Keystone species, however, have a disproportionate impact on their environment relative to their abundance.
3. Evaluate the roles: Keystone species often have roles such as top predators, pollinators, or ecosystem engineers, which help maintain the balance and diversity of the ecosystem. Their removal can lead to significant changes in the ecosystem structure.
4. Analyze the consequences of removal: Removing a dominant species might lead to changes in resource availability but may not drastically alter the ecosystem's structure. In contrast, removing a keystone species can lead to a collapse of the ecosystem or significant changes in species composition.
5. Summarize the key difference: The key difference is that dominant species are defined by their abundance, while keystone species are defined by their critical ecological roles and the significant impact they have on their environment, despite not being the most abundant.