1. Human Populations

2. Human Population Growth
Like other organisms, the human population increases with time
For most of human existence, growth rate was slow
Life was harsh, food was scarce, incurable diseases
50% of children didn’t survived to adulthood
500 years ago: population began to grow rapidly
Agriculture and industry
Reliable food supply
Sanitation, medicine, and health care

3. Patterns of Population Growth
Demography – study of human population growth
Birthrates, death rate, age structure of a population
Demographic Transition: dramatic change in birth and death rates

4. Demographic Transition
Begin Demographic Transition
Death rate begins to fall, and birthrates remain high
Rapid Growth: births greatly exceed deaths
South America, Africa, and Asia
Growth Slows: birth falls
Increased levels of education
Higher standards of living
Families have fewer children

5. Demographic Transition Cont.
Growth Stops: demographic transition is complete
birthrate falls to meet the death rate
US, Japan, much of Europe
Most of the population growth occurs in 10 countries
India & China

7. Age Structure Diagram Graphs of # individuals in each age group
Used to predict future growth
United States: slow growth
Rwanda: double in 30 years

9. Future Growth Prevalence of life-threatening diseases
AIDS, Malaria, and cholera
2050: 9 billion people