Apes Unit 3 Review

r-Strategist

Small size, weak, short life, rapid maturation, many offspring, and rarely care for young. 

K-Strategist

Large size, strong, long life, slow maturation, few offspring, and cares for young. 

Population

All members of the same species living in the same place at the same time. 

Population Size

Total number of organisms in a given area. 

Population Density

Total number of organisms per unit area.

Population Dispersion

The spatial arrangement or distribution pattern of organisms in an area. 

Clumped Dispersion

Organisms grouped in patches (most common type, caused by resource availability, mating, protection, or caring for young).

Uniform Dispersion

Organisms evenly spaced out (often due to territoriality or competition). 

Random Dispersion

Organisms distributed unpredictably with no specific pattern (e.g., dandelions). 

Factors Affecting Population Growth

Birth, Death, Immigration, and Emigration. 

Natural Growth Rate

Birth rate minus death rate (Birth - Death). 

Crude Birth Rate (CBR)

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

Crude Death Rate (CDR)

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

Rule of 70

Formula to estimate the number of years it takes for a variable to double: Doubling Time = 70 / Annual Growth Rate(%)

Total Fertility Rate (TFR)

The average number of children a woman will have in her lifetime / reproductive years. 

Replacement Level Fertility Rate

The average number of children a couple must bear to replace themselves (roughly 2.1 in developed countries).

Biotic Potential

Maximum rate at which a population can grow under ideal, unlimited conditions. 

Environmental Resistance

Factors (like limited resources, disease, and predation) that limit population growth.

Carrying Capacity (K)

Maximum number of a species' individuals that an ecosystem can sustainably support.

Exponential Growth

Rapid population growth with no environmental resistance, forming a J-shaped curve. 

Logistic Growth

Population growth that slows as it reaches carrying capacity, forming an S-shaped curve. 

Population Dynamics (Fluctuation Types)

Stable, Irruptive, Cyclic, and Irregular. 

Density-Dependent Limiting Factors

Factors whose effect changes with population density, such as competition, predation, disease, and resource availability.

Density-Independent Limiting Factors

Factors that affect population size regardless of density, such as natural disasters, weather, temperature, and pesticides.

Developing Countries (LDCs)

Countries with lower average incomes, weak social support systems, agricultural economies, and rapid population growth.

Developed Countries (MDCs)

Countries with higher incomes, strong social support systems, industrial economies, and slower population growth.

World Population Milestone

Reached 8 billion around 2022-2024, growing exponentially since the 1700s. 

Factors Influencing Birth Rates

Urbanization, cost of raising children, child labor needs, education/employment for women, availability of birth control, and religious/cultural beliefs.

Factors Influencing Death Rates

Increased food supply/nutrition, improved sanitation, advanced medicine, and access to healthcare.

Infant Mortality Rate

Number of deaths of infants under one year old per 1,000 live births. 

Type I Survivorship Curve

High probability of surviving to adulthood and living long, with death occurring mostly in old age (e.g., humans).

Type II Survivorship Curve

Chance of survival is independent of age; constant mortality rate throughout life (e.g., birds).

Type III Survivorship Curve

High probability of death in early life stages, but survivors live a long time (e.g., trees, fish).

Factors Affecting Migration

Economics, war, political freedom, religious freedom, and environmental refugees. 

Age Structure Diagrams

Visual distribution of males and females across age groups (Pre-reproductive: 0–14, Reproductive: 15–44, Post-reproductive: 45–85+)

Demographic Transition Model (DTM)

Model examining birth and death rates to explain population growth changes through 4-5 stages. 

DTM Stage 1 (Pre-Industrial)

High birth rates, high death rates, and zero population growth (nomadic lifestyle). 

DTM Stage 2 (Transitional)

High birth rates, rapidly dropping death rates, and exponential population growth due to better food/medicine.

DTM Stage 3 (Industrial)

Dropping birth rates, low death rates, and continued rapid population growth as society urbanizes.

DTM Stage 4 (Post-Industrial)

Low steady birth rates, low steady death rates, and stabilizing total population growth. 

Methods to Slow Population Growth

Family planning (education, contraceptives, healthcare) and empowering women through education and jobs.