How do humans make a living, Part II: Agriculture
February 25, 2005
How do humans make a living?
• Social Characteristics– Subsistence– Exchange Patterns– Ecological Relationships– Cultural Practices (religion, ritual)– Trade goods
Part I: How did this happen?
• Traditional View: Revolutionary innovation leading to a better life
• Foragers managed the land– Burning– Weeding
• Gradual, seasonal back and forth• Adaptive strategy for managing risk.
Part I: How did this happen?
• Strategy:
Foraging FarmingReturn: Low HighRisk: Low HighDelay: Short
Long
Part I: How did this happen?
• Foragers become farmers when:– Return on effort increases and– Risk and Delay decrease
• Diamond: – Degradation of environment and
resources (game animals)– Climatic changes
Part II: When did this happen?
• Earliest evidence for domestication is 10,000 ybp (Fertile Crescent).
• Evolutionary “blink of an eye.”
Part III: Where did this happen?
• Middle East (Wheat, barley, sheep, goats, cattle, pigs – 10,000bp)
• South China (Rice, water buffalo, dogs, pigs – 8,500)
• North China (Millet, Dogs, pigs, chickens – 7,500)
• African Sahel (Sorghum, pearl millet, rice – 4,000)
Part III: Where did this happen?
• Mexico (Maize, beans, squash, dogs, turkeys – 4,700)
• Andes (Potato, quinoa, llama, alpaca, guinea pigs – 4,500)
• Eastern U.S. (Goosefoot, marsh elder, sunflower, squash – 4,500)
Part III: Where did this happen?
Part IV: Why did it happen there?
• Climate• Species available for domestication• Topography• Latitude
Part IV: Why did it happen there?
Why the Middle East?
• Largest Mediterranean zone with most climatic variation (seasons)
• Greatest species diversity.• Greatest topographic diversity• Less competition from hunter
gatherers
Part V:Adaptive Strategies in Farming
• Benefits – Costs = Net Benefit• Extensive agriculture:
– Low input, low cost, high net benefit
• Intensive agriculture– High costs, high net benefit
• In terms of the factors, neither is inherently better.
Extensive: Swidden Agriculture
Extensive: Swidden Agriculture
• Population Size• Growth Cycles; rotating fields
Extensive: Swidden Agriculture
Intensive Agriculture
• Labor Intensive• Land Intensive• Capital Intensive• Machinery Intensive
Labor Intensive
Land Intensive
Capital/Machinery Intensive
Part VI: What were the consequences?
• Population growth• Intensifying food production• “Flourescence”
– Hopewell– Mississippian
Part VI: What were the consequences?
• Declining health• Increased workload• Social Changes
Declining Health
Declining Health
Increasing Workload
Social Changes
• Mississippian Flourescence – Increased population– Larger settlements– Social complexity– “Mound Builders”
Green Revolution
• Effort by USAID, agencies and governments to end hunger through technology
• Increase crop yields by focusing on “inputs”– Seed hybrids, fertilizers, pesticides,
irrigation and machinery
Green Revolution
• Debt• Environmental Degradation• Land reallocation (former land
owners became poor tenant farmers)• Loss of control of farming methods• Increase in production• Increase in poverty
Green Revolution
• Food First estimates 786 million hungry people in the 1990s
• Governments tried to store grain that people couldn’t afford to buy.