Population Dynamics

Size

Number of individuals in a population.

Density

The number of organisms in a particular area; larger organisms typically have lower density due to resource competition.

Distribution

The arrangement of individuals in a population across a geographic area; can be clumped, uniform, or random.

Age Structure

The composition of a population, indicating the proportion of individuals at different age levels.

Crude Birth Rate

The number of live births per 1,000 people in a population over a certain period.

Crude Death Rate

The number of deaths per 1,000 people in a population over a certain period.

Exponential Growth

Population growth where the increase occurs at a constant rate; results in a J-shaped curve.

Carrying Capacity (K)

The maximum population size that an environment can sustain over time.

Biotic Potential

The maximum reproductive capacity of a species in ideal environmental conditions.

Demographic Transition

The model showing how countries transition from high birth and death rates to low birth and death rates as they industrialize.

R-selected Species

Species that produce many offspring with low parental investment and high mortality rates.

K-selected Species

Species that produce few offspring but invest significant parental care to ensure their survival.

Survivorship Curve

Graph showing the number of survivors at different ages in a population.

Immigration

The movement of individuals into a population or area.

Emigration

The movement of individuals out of a population or area.

Total Fertility Rate (TFR)

The estimated average number of children a woman will have during her lifetime based on current age-specific fertility rates.

Replacement-level Fertility

The number of children a couple must have to maintain the population size.

Linear Growth

Growth that increases by a fixed amount over time, resulting in a straight line when graphed.

Environmental Resistance

All factors that limit the growth of a population.

Life Expectancy

The average number of years an individual is expected to live.

Population Density

The number of individuals per unit area in a population.

Infant Mortality Rate

The number of infant deaths per 1,000 live births.

Family Planning

Services that help individuals and couples decide on the number and spacing of their children.

Asexual Reproduction

Reproduction that involves a single parent producing genetically identical offspring.

Sexual Reproduction

Reproduction that involves the combination of genetic material from two parents.

Dieback

A sharp reduction in population size when it exceeds the carrying capacity.

Population Dynamics

The factors that influence changes in population size and composition.

Population Change

An increase or decrease in a population's size.

Growth Rate

The rate at which a population increases or decreases due to births, deaths, immigration, and emigration.

J-shaped Curve

Graph shape representing prolonged exponential growth.

S-shaped Curve

Logistic growth curve where population growth slows as it approaches carrying capacity.