Population Characteristics and Human Growth

Comprehensive vocabulary flashcards covering population dynamics, environmental limiting factors, reproductive strategies, and human demographic metrics based on the lecture transcript.

Population

A group of individuals of the same species inhabiting an area.

Natality

The number of individuals added to the population through reproduction over a particular time period.

Mortality

The number of deaths in a population over time; in human populations, it refers to the number of deaths per $1,000$ individuals each year.

Sex Ratio

The number of males and females in a population, which influences growth rates depending on whether a species forms pairs or if one male mates with many females.

Age Distribution

The number of individuals in a population that are young, adults, or old, which helps predict whether a population will grow, stay stable, or decline.

Biotic Potential

The natural ability of a species to produce offspring.

Limiting Factors

The factors that prevent unlimited population growth and act to limit the size of a population.

Environmental Resistance

The collective set of different limiting factors that act on a population.

Extrinsic Limiting Factors

Limiting factors that come from outside the population, such as predators, lack of food, limited sunlight, or natural disasters.

Intrinsic Limiting Factors

Limiting factors that come from within the population itself, such as behavioral changes involving reproduction or care of young due to crowding.

Density-dependent Limiting Factors

Factors that have a stronger effect as a population becomes more crowded, including competition for food, spread of disease, and predation.

Density-independent Limiting Factors

Factors that affect populations regardless of size or density, such as storms, floods, droughts, or extreme temperatures.

Death Phase

The final decrease in a population, often seen in bacteria, caused by the accumulation of toxic waste products.

Carrying Capacity

The maximum number of organisms an environment can support over time, regulated by limiting factors like food, water, and space.

K-strategists

Species that are usually large, live long, have few offspring, provide significant parental care, and inhabit stable environments near carrying capacity (e.g., humans, elephants).

R-strategists

Small organisms with short lifespans that produce many offspring with little to no parental care, often experiencing rapid population growth and crashes (e.g., bacteria, insects).

Rule of 70

A formula used to determine population doubling time by dividing 70 by the annual growth rate percentage.

More-Developed Countries

Economically advanced regions including Europe, North America, Japan, Australia, and New Zealand, with a combined population of roughly $1.2 \times 10^9$ people.

Less-Developed Countries

Nations primarily in Asia, Africa, and Latin America where nearly $3 \times 10^9$ people survive on less than $US\,2$ per day.

IPAT Formula

A method to measure environmental impact where $I = P \times A \times T$ (Impact = Population $\times$ Affluence $\times$ Technology).

Population Density

The number of people per unit of land area, relating population size to available resources.

Geometric Growth

Thomas Malthus's thesis that human populations, if unchecked, double every 25 years in a sequence like $1, 2, 4, 8, 16...$

Arithmetic Growth

The principle that food production only increases by a constant amount in each time period, following a sequence like $1, 2, 3, 4, 5...$

Ecological Footprint

A measure of the total land and water area a population requires to produce the resources it consumes and absorb its generated waste.

Demography

The scientific study of human populations, including their characteristics and how those traits affect growth.

Total Fertility Rate

The most important factor determining human population growth, measuring the average number of children born to a woman over her lifetime.

Replacement Fertility

A total fertility rate of $2.1$, where parents produce exactly enough children to replace themselves.

Zero Population Growth

A state where the total number of births equals the number of deaths, causing population growth to stop.

Gross National Income (GNI)

An index measuring the total value of goods and services generated within a country and income earned by citizens abroad.

GNI PPP (Purchasing Power Parity)

A technique used to adjust GNI based on the actual purchasing power per person within a nation, accounting for different costs of living.

Microcredit

Small loans, often less than $US\,200$ and without collateral, provided to the rural poor to start businesses, exemplified by the Grameen Bank.

Human Energy Pyramid

A graphical model showing energy flow through a food chain, illustrating that only about $10\%$ of energy is transferred between trophic levels.

Demographic Transition Model (DTM)

A four-stage framework explaining how population growth and structure change as a country transitions from an agrarian to an industrialized society.

Biological Carrying Capacity

The dynamic equilibrium where population size stabilizes because resource availability matches the consumption rate.

Cultural Carrying Capacity

The maximum number of people an environment can support while maintaining a specific, acceptable standard of living and quality of life.