1. A Growing Human Population

2. Societies

3. 1. Hunter-Gatherers Small populations (25-30 people) Widely dispersed
Obtained their food by hunting, fishing and gathering wild plants
Used hand tools

4. Nomadic according to availability of plants and animals
Used only what they needed for survival
Caused very little damage to the environment

5. 2. Agricultural Society
10,000 years ago people began to raise animals and grow crops
Occurred at many different places at about the same time

6. Allowed people to produce more food than gathering wild plants
Used horses and ox drawn equipment
Began creating their own ecosystems
Increased the carrying capacity of the land
human population began to grow
larger families advantageous

7. 3. Industrial Revolution

8. Industrial Revolution -
Raised standard of living
Goods produced in factories
Tractors used in agriculture
Required large amounts of fossil fuels
Improved sanitation
Improved nutrition
People could shop for their food

9. Most people able to survive through childhood to reproduction
Improved medical care
Decrease in death rates is the biggest factor contributing to the explosive growth during the last 200 years
Most people able to survive through childhood to reproduction
Use of technology may allow the human population to surpass the Earth’s carrying capacity

10. Human Population Continues to Grow

11. Human population grew very slowly for thousands of years, but began rapid growth in the 1800’s
Human population doubled between 1800 and 1930
1975 the human population reached 4 billion, and exceeded 5 billion by 1987

12. Population Histograms

13. Population Histograms
Graph that shows data frequency
x-axis: % of population
right females
left males
y-axis: birth year or age y
males
females
age x 50 50
% of population

14. Growing Population More births than deaths Pyramid shape
Developing countries

15. Stable Population
Births = Deaths
Developed Countries
Column shape

16. Declining Population More deaths than births Indented at the bottom
Developed Countries

17. Demographic Transition
In 2010 the world’s population surpassed 7 Billion
Today, the world’s population is over 7.3 billion
7,345,000,000 - World
324,292,000 - U.S.
Human population continues to grow, but growth has slowed due to lower birth rates in most parts of the world
most of the increase in human population is occurring in the developing countries

18. Birth and death rates are both high in preindustrial societies and results in slow, if any, population growth
Improved health care increases a population: higher birth rates and longer life span

19. Birth rates fall until they roughly equal death rates and population growth slows and stops
marry later
have children later
birth control
parents realize children are likely to grow to adulthood
consider the number of children they can care for
children recognized as an expensive responsibility