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.