Chapter 6: The Human Population

Vocabulary flashcards covering key terms related to population dynamics, reproductive patterns, age structure, and global population trends from Chapter 6: The Human Population.

Carrying capacity

Maximum population of a given species that a particular habitat can sustain indefinitely.

Overshoot

When a population temporarily exceeds carrying capacity, often followed by a crash.

Environmental resistance

Sum of all factors that limit population growth.

Limiting factors

Conditions that limit population size, such as precipitation on land and water temperature, depth, and clarity in aquatic environments.

Density-dependent factors

Factors whose effects intensify as population density increases (e.g., competition, disease).

J-curve growth

Exponential population growth resulting in a J-shaped curve.

S-curve growth

Growth that rises rapidly but levels off near carrying capacity, producing an S-shaped curve.

r-selected species

Species with a high reproductive rate, early maturity, many offspring, and little parental care; populations are often irregular.

K-selected species

Species that reproduce later, have few offspring, long lifespans, and substantial parental care; populations approximate carrying capacity.

Survivorship Type I

Late loss; high survival of young with mortality concentrated in older ages.

Survivorship Type II

Constant loss; relatively constant probability of death across ages.

Survivorship Type III

Early loss; high mortality among offspring.

Reproductive potential

Capacity for rapid population growth due to traits like early reproduction and many offspring.

Reproductive maturity

Age at which an individual can reproduce.

Life span

Maximum or typical length of life for a species.

Population growth rate

The rate at which a population size changes per year, influenced by births, deaths, immigration, and emigration.

Total fertility rate (TFR)

Average number of children born to women of childbearing age in a population.

Replacement-level fertility

Approximately 2.1 children per couple needed to maintain population size (accounts for child mortality).

Crude birth rate

Number of live births per 1,000 people in a population per year.

Crude death rate

Number of deaths per 1,000 people in a population per year.

Age structure

Distribution of people among age groups; pre-reproductive (0–14), reproductive (15–44), post-reproductive (45+).

Pre-reproductive

Ages 0–14.

Reproductive

Ages 15–44.

Post-reproductive

Ages 45 and older.

Demographic momentum

Continued population growth after fertility declines due to a large cohort entering reproductive age.

Demographic transition

Shift from high birth and death rates to low birth and death rates as countries industrialize.

Population projection

Forecasts of future population size by organizations such as the UN, US Census Bureau, and IIASA.

Urbanization

Movement of people from rural to urban areas.

Migration

The movement of people into and out of geographic areas for reasons such as jobs, persecution, or environment.

Life expectancy

Average number of years a person is expected to live in a population.

Infant mortality rate

Number of babies per 1,000 who die before their first birthday.

One-child policy

China's policy to limit most families to one child, with later shifts toward two children; led to skewed sex ratios.

Two-child policy

China's policy allowing two children per family, implemented to counter aging and labor shortages.

Aging population

A population with a growing share of older individuals; e.g., Japan's high elderly population and low birth rates.

Ecological footprint

The per-person impact of consumption and waste on Earth's natural resources.

Cultural carrying capacity

Maximum number of people who could live in reasonable freedom and comfort indefinitely without degrading Earth's ability to sustain future generations.