A Level Biology Practice Exam

What does species evenness indicate?

1. The number of species in a given area

2. How evenly represented the species are

3. The frequency of the most dominant species

4. The rate of species extinction

The correct answer is: How evenly represented the species are

Species evenness is a measure of how similar the abundances of different species are within a given area. When assessing biodiversity, it's not just the number of species present that matters, but also how those species are distributed in terms of their population sizes. High species evenness indicates that a community has a more equal representation of various species, whereas low species evenness suggests that one or a few species dominate the community, leading to an imbalance. Therefore, the indication of how evenly represented the species are in a community provides insights into the ecological health and stability of that environment. Communities with high evenness are generally more resilient to disturbances and more likely to support a variety of functions and services.