human population

Human Population

BIO 103

Human Ecology

Dr. Phoebe Smith

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

Hunter-Gatherers

• Consumed about 0.1% of biological production in the ecosystem

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

• Largest populations in river valleys of India and China

• 14th c.--plague reduces world population by 25%

• 16th c.--European colonialism and trade

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

Green Revolution

• ~40 years ago

• High-yield crop varieties (rice, wheat and corn)

• What are the environmental effects of fertilizers, pesticides, etc.?

Current population growth rates

Population regulation

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

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