APES Unit 3 Vocab

Demography

the study of human populations and population trends

Population Density

the number of individuals per unit area at a given time

Age Structure Diagram

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

Crude birth rate

the number of  births per 1,000 individuals per year

Crude death rate

The number of deaths per 1,000 individuals per year

Infant Mortality

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

Total fertility rate

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

Demographic Transition

a country moving from a subsistence economy to industrialization and increased affluence if it undergoes a predictable shift in population growth

Doubling time

the number of years it takes a population to double

Exponential Growth

growth pattern in which the individuals in a population reproduce rapidly because more births occur with each step in time, when graphed this produces a j-shaped curve

Logistic Growth

growth that is initially exponential, but slows as the population approaches the carrying capacity of the environment 

Natural increase

Crude death rate subtracted from crude birth rate 

Migration

the movement organisms from one area to another area

Emigration

the movement of people out of a country or region

Immigration

the movement of people into a country or region, from another country or region

Negative population growth

the actual decline in population due to less than replacement births or extensive diseases

Doubling time

The number of years it takes a population to double calculated by TD = 70/r (%)

Fecundity

the potential offspring production for a female

r-selected species

a species that has a high intrinsic growth rate, which often leads to population overshoots and diebacks

K-selected species

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

Survivorship curve

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

Overshoot

when a population becomes larger than the environment’s carrying capacity

Dieback

a rapid decline in a population due to death

Carrying capacity

the limit of how many individuals in a population the environment can sustain

Biotic potential

the maximum reproduction rate of a population in ideal conditions