survival curve

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survival curve A graph that shows the relationship between the survival and age of a population of a particular species. Survival can be represented as the percentage of individuals of the original population that have survived after a specified time. Some types of organism, notably those that produce many offspring (e.g. bacteria), have a low survival rate in the early stages of development (line A on graph; see r selection). Other organisms, which have a low rate of reproduction, tend to be long-lived and their population numbers are maintained over a long period (line B on graph; see K selection). This type of survival curve is typical of a human population in a developed country.