Population growth

Objective: Explain birth and death rates and immigration and emigration, distinguish their meanings, and apply them to a described case.

Birth and death rates: Births add individuals and deaths remove individuals during a specified interval. Immigration and emigration: Immigration adds arriving individuals and emigration removes departing individuals. Population change is an accounting result of births, deaths, arrivals, and departures. Growth models add assumptions about rates and environmental conditions. Exponential growth is useful for some intervals but cannot continue indefinitely in a finite environment. Logistic growth is also a simplification because resources and interactions can change. Age structure can influence future growth even when current totals appear stable. Specify the interval and population boundary before calculating or interpreting change. Application: A population gains newborns and loses individuals to mortality. This most directly illustrates birth and death rates. Animals enter and leave a monitored habitat. This most directly illustrates immigration and emigration.

Objective: Explain population change and exponential growth, distinguish their meanings, and apply them to a described case.

Population change: Net change equals births plus immigration minus deaths and emigration. Exponential growth: Exponential growth occurs when the per-capita growth rate remains approximately constant under the model's assumptions. Population change is an accounting result of births, deaths, arrivals, and departures. Growth models add assumptions about rates and environmental conditions. Exponential growth is useful for some intervals but cannot continue indefinitely in a finite environment. Logistic growth is also a simplification because resources and interactions can change. Age structure can influence future growth even when current totals appear stable. Specify the interval and population boundary before calculating or interpreting change. Application: A census combines all four demographic components. This most directly illustrates population change. An unconstrained model adds increasing numbers each interval. This most directly illustrates exponential growth.

Objective: Explain logistic growth and age structure, distinguish their meanings, and apply them to a described case.

Logistic growth: A logistic model reduces growth as population size approaches a modeled carrying capacity. Age structure: Age structure describes the distribution of individuals among age groups and influences population dynamics. Population change is an accounting result of births, deaths, arrivals, and departures. Growth models add assumptions about rates and environmental conditions. Exponential growth is useful for some intervals but cannot continue indefinitely in a finite environment. Logistic growth is also a simplification because resources and interactions can change. Age structure can influence future growth even when current totals appear stable. Specify the interval and population boundary before calculating or interpreting change. Application: A growth curve slows near its assumed environmental limit. This most directly illustrates logistic growth. A population has many individuals approaching reproductive age. This most directly illustrates age structure.