APES 3 VOCAB

Age structure diagram

A visual representation of the number of individuals within specific age groups for a country, typically expressed for males and females.

Biotic potential

Under ideal conditions with unlimited resources available, every population has a maximum potential for growth.

Carrying capacity

The limit to the number of individuals that can be supported by an existing habitat or ecosystem, and is denoted as K.

Child mortality

The number of deaths of children under age 5 per 1,000 live births.

Crude birth rate (CBR)

The number of births per 1,000 individuals per year.

Crude death rate (CDR)

The number of deaths per 1,000 individuals per year.

Demographer

A scientist in the field of demography.

Demography

The study of human populations and population trends.

Density-dependent factor

A factor that influences an individual’s probability of survival and reproduction in a manner that depends on the size of the population.

Density-independent factor

A factor that has the same effect on an individual’s probability of survival and the amount of reproduction at any population size.

Developed countries

Countries that have relatively high levels of industrialization and income.

Developing countries

Countries that have relatively low levels of industrialization and income.

Dieback/ die-off

A rapid decline in a population due to death.

Doubling time

The number of years it takes a population to double.

Emigration

The movement of people out of a country or region.

Environmental justice

The study of the disproportionate exposure to environmental hazards experienced by people of color, recent immigrants and people of lower socio-economic backgrounds; and is both an academic field and a social movement.

Exponential growth model

A growth model that estimates a population’s future size after a period of time based on the biotic potential and the number of reproducing individuals currently in the population.

Family planning

The regulation of the number or spacing of offspring through the use of birth control.

Fecundity

The ability to produce an abundance of offspring.

Immigration

The movement of people into a country or region, from another country or region.

Infant mortality

The number of deaths of children under 1 year of age per 1,000 live births.

IPAT equation

A conceptual representation of the three major factors that influence environmental Impact: Population of humans, Affluence, Technology.

J-shaped curve

The curve of the exponential growth model when graphed.

K-selected species

A species with a low intrinsic growth rate that causes the population to increase slowly until it reaches the carrying capacity of the environment.

Life expectancy

The average number of years that an infant born in a particular year in a particular country can be expected to live, given the current average life span and death rate in that country.

Limiting resource

A resource that a population cannot live without and that occurs in quantities lower than the population would require to increase in size.

Logistic growth model

A growth model that describes a population whose growth is initially exponential, but slows as the population approaches the carrying capacity of the environment.

Net migration rate

The difference between immigration and emigration in a given year per 1,000 people in a country.

Overshoot

When a population becomes larger than the environment’s carrying capacity.

Population growth models

Mathematical equations that can be used to predict population size at any moment in time.

Population growth rate/ intrinsic growth rate

The number of offspring an individual can produce in a given time period, minus the deaths of the individual or its offspring during the same period.

Population momentum

Continued population growth after growth reduction measures have been implemented.

Population pyramid

An age structure diagram that is widest at the bottom and smallest at the top, typical of developing countries.

r-selected species

A species that has a high intrinsic growth rate, and their population typically increases rapidly.

Replacement-level fertility

The total fertility rate required to offset the average number of deaths in a population in order to maintain the current population size.

Rule of 70

A method which dictates that by dividing the number 70 by the percentage population growth rate we can determine a population’s doubling time.

S-shaped curve

The shape of the logistic growth model when graphed.

Survivorship curve

A graph that represents the distinct patterns of species survival as a function of age.

Theory of demographic transition

A theory that states that a country moves from high to lower birth and death rates as development occurs and that country moves from a preindustrial to an industrialized economic system.

Total fertility rate (TFR)

An estimate of the average number of children that each woman in a population will bear throughout her childbearing years.

Type I survivorship curve

A pattern of survival over time in which there is high survival throughout most of the life span, but then individuals start to die in large numbers as they approach old age.

Type II survivorship curve

A pattern of survival over time in which there is a relatively constant decline in survivorship throughout most of the life span.

Type III survivorship curve

A pattern of survival over time in which there is low survivorship (a high death rate) early in life with few individuals reaching adulthood.