1. Limits to Growth / Human Population
Ch 5.2 / Ch 5.3

2. Limiting Factors
Limiting Factors: factors that control population growth
Density-Dependent: operates when population density reaches a certain level
Examples: competition, herbivory, predation, disease, parasitism, and stress from overcrowding
Density-Independent: effects population regardless of density
Examples: hurricanes, droughts, floods (natural disasters)

3. Density-dependent Factors
Competition
individuals compete for essential resources
Predation / Herbivory
Predator v. Prey
Parasitism
large population = more chance for disease to spread
Overcrowding
Stress for space causes individuals to fight → causes stress → weaken the body for diseases

4. Human Population Growth
Beginning: Population grew slowly
Causes: harsh environment, scarce food, predators and diseases were common
Then: Population is growing rapidly (exponential)
Causes: sanitation, improved nutrition, medicine, improved healthcare
Now: Population is still growing but at a slower pace

5. Comparing Population Growth
Demography: examines characteristics of human population and attempt to explain how populations change over time
Birth rates
Death rates
Age structure

6. Demographic Transition
Stage I: birth rates and death rates are high
Stage II: nutrition, sanitation, medicine
lead to low death rates; birth rates remain high
Stage III: levels of education and standards of living rise so birth rates fall