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