Population size

Definition

Population size is the total number of individuals of a species within a specific area at a given time. It is a fundamental metric in ecology for understanding species dynamics and ecosystem health.

5 Must Know Facts For Your Next Test

1. Population size can be influenced by birth rates, death rates, immigration, and emigration.
2. Large population sizes can lead to increased competition for resources such as food, habitat, and mates.
3. Small population sizes are more vulnerable to genetic drift and inbreeding, which can reduce genetic diversity.
4. The carrying capacity of an environment limits the maximum population size that it can sustain over time.
5. Population size data is crucial for conservation efforts, helping to identify endangered species and plan protective measures.

Review Questions

• What factors can cause changes in the population size of a species?
• Why are small population sizes more susceptible to genetic issues?
• How does carrying capacity affect population size?

Related terms

carrying capacity:

The maximum number of individuals that an environment can sustainably support without degrading the habitat

birth rate:

The number of live births per 1,000 individuals in a population per year

immigration: The movement of individuals into a population from other areas