Human Population

1
Human Population

• BIO 103
• Human Ecology
• Dr. Phoebe Smith

2
History of human evolution

• Homo habilis
• 3 mya in Africa
• Use of simple, stone tools
• Homo erectus
• 1 mya in Europe Asia
• Homo sapiens
• 1.3 mya in Africa
• Out of Africa theory

3
Hunter-Gatherers

• Consumed about 0.1 of biological production in
  the ecosystem

4
Agricultural Revolution

• Ocurred 12,000 years ago in Middle East
• Led to domestication of plants (crops) and
  animals
• Increased percentage of biological production
  consumed
• Increased carrying capacity

5

• Largest populations in river valleys of India and
  China
• 14th c.--plague reduces world population by 25
• 16th c.--European colonialism and trade

6
Industrial Revolution

• 18th c.
• Agriculture wheat, corn, potatoes, sweet
  potatoes and rice
• Technology increased production and carrying
  capacity
• By the 19th c., large families (for labor) were
  no longer necessary

7
Green Revolution

• 40 years ago
• High-yield crop varieties (rice, wheat and corn)
• What are the environmental effects of
  fertilizers, pesticides, etc.?

8
Current population growth rates
9
Population regulation

• Are there cultural practices that limit
  population increase?
• Territoriality
• Polygamy
• Infanticide
• Breast-feeding

10
Consequences of population explosion

• Quality of life
• Lack of food
• Environmental refugees migrate to cities from
  rural areas
• Competition for resources
• War in Iraq
• May be controlled
• Birth control
• Education