Survivorship curve

Definition

A survivorship curve is a graphical representation showing the number or proportion of individuals surviving at each age for a given species or group. It helps illustrate the mortality rate of a population over time.

5 Must Know Facts For Your Next Test

1. There are three main types of survivorship curves: Type I, Type II, and Type III.
2. Type I curves show low early mortality rates with most individuals living to old age (e.g., humans).
3. Type II curves depict a constant mortality rate throughout the lifespan (e.g., birds).
4. Type III curves indicate high early mortality rates with few individuals reaching adulthood (e.g., many fish and invertebrates).
5. Survivorship curves help biologists understand the reproductive strategy and life history traits of different species.

Review Questions

• What are the characteristics of a Type II survivorship curve?
• How does a Type III survivorship curve differ from a Type I curve?
• Why are survivorship curves important in studying population ecology?

Related terms

Life Table: A table that shows the probability of survival and reproduction through different ages for a given population.

Population Demographics: The statistical study of populations, including their size, growth, density, distribution, and rates of births, deaths, immigration, and emigration.

Carrying Capacity: The maximum number of individuals in a population that an environment can support sustainably.