week 5 reading for climate class - Early Agriculture and Civilization: Comprehensive Notes

Early Agriculture and Civilization

Origins and Independent Development

• Agriculture originated independently in several world regions within the last $12,000$ years.
• Earliest Developments (Largest Impact):
  • Fertile Crescent region of Mesopotamia (eastern Mediterranean).
  • Yellow River Valley in northern China (fig. 7.1).
• Later Developments (Thousands of years later):
  • Central American lowlands.
  • High terrain around the Peruvian Andes.
  • Tropics of Africa and New Guinea.
• Evidence of Independent Origin:
  • Geographic separation of these areas.
  • Each region possessed different natural food sources, requiring distinct forms of domestication.

Hunter-Gatherer Expertise and the Decision Not to Farm

• Botanical Experts: Studies of remote Stone Age cultures show them to be world-class botanists within their habitats, distinguishing hundreds to thousands of plants. This expertise was vital for survival.
  • Motivation: Gather food without making fatal errors (e.g., distinguishing poisonous roots, nuts, berries, mushrooms).
  • Example: A colleague nearly died from a wrong mushroom choice.
• Agriculture Was Not Inevitable: The switch from hunting-fishing-gathering was not a foregone conclusion, due to several factors:
  • Nutritional Balance: Hunter-gatherers in regions like the Fertile Crescent derived food from many sources, promoting natural nutritional balance.
  • Risk of Malnutrition: Overreliance on $1-2$ crops could lead to malnutrition due to insufficient protein or fat loss.
  • Energy Expenditure: Harvesting some wild grains in the Near East today requires less energy than cumulatively planting, tending, and harvesting their domesticated equivalents.
    • Early people likely made rational choices to maximize food, minimize time, and expend the least energy.

The Fertile Crescent: Factors Leading to Agriculture

• Unique Natural Bounty: The semi-arid grasslands of this region grew an unusual variety of edible wild grains ideal for domestication (table 7.1).
  • Cereals: Two types of wheat (emmer and einkorn), barley, and rye (easily gathered carbohydrate sources).
  • Legumes: Peas and lentils (good protein sources).
• Climatic Advantage: The semi-arid climate with long dry seasons encouraged plants to produce seeds for reproduction, which are convenient and edible food sources for humans.
  • Contrast: Well-watered forests yield little edible vegetation; deserts are barren.
• Combined Resources for Nutrition: People could rely on crops for a portion of their food but still supplement their diet through gathering wild seeds, hunting, and fishing, thus avoiding malnutrition.
• Early Technical Innovations (Coincident with Agriculture's Start):
  • Primitive stone sickles for cutting grain.
  • Woven baskets for carrying grain.
  • Mortars and pestles for grinding grain.

Transition to Agriculture in the Fertile Crescent

• Early Stages (Gathering): Initially, people simply gathered wild grains and legumes because they were available, tasted good, and were one seasonal food source among many.
• Human Intervention (by $11,000$ years ago): Cereals related to wild varieties began appearing outside their natural distributions (e.g., Tigris-Euphrates floodplain), indicating human manipulation.
• Unconscious Selection and Domestication:
  • Grain Enlargement: Slowly, preserved grains became larger than their wild forms; peas, for example, increased by a factor of ten.
  • Efficiency-Driven Selection: People repeatedly chose the largest grains/vegetables to gather more food in less time.
  • Parallel to Modern Breeding: This unconscious selection process gradually produced results similar to modern agricultural specialists developing improved crop strains.
• Seed Dispersal and Sprouting: Grains picked but uneaten were scattered around campsites or villages; some passed through human digestive systems and sprouted in waste piles, growing in fertile, moist locations handy for the next season.
• Intentional Planting: Slowly, hand-selected wild grains became a larger part of the diet. People began using sticks to poke holes and plant them, though still heavily reliant on hunting and gathering.
  • Grains were easy to plant and matured quickly (usually within $3$ months).
• Permanent Settlements (Nearly $10,500$ years ago):
  • First evidence: Farm villages with populations in the hundreds.
  • Remains: Mud-brick houses, animal bones indicating year-round butchering.
  • Significance: Direct evidence of conversion to farming, with people staying in one place to tend fields and watch over food stores.

Interdependence and Population Growth

• Human-Crop Interdependence: Over centuries, continuous selection of the largest seeds led crops to evolve into hybrids incapable of surviving in the wild against natural competition.
• Population Boom: With freedom from constant movement, reduced need to carry young indefinitely, and dependable food sources, people could have children more frequently, leading to population increases.

Animal Domestication in the Fertile Crescent

• Abundance of Suitable Wild Animals: The Fertile Crescent was naturally home to many types of wild animals easy to domesticate, as noted by Jared Diamond.
  • Challenge: Many mammal types are too wild, skittish, solitary, or small for domestication.
• Gradual Domestication: Wild predecessors of goats, sheep, pigs, and cattle evolved from herding semi-wild flocks to full domestication.
• Key Domesticates (By $9,500$ years ago): Goats, sheep, pigs, cattle.
  • Dogs: Guarded villages, scavenged, provided warmth, and occasionally food.
• Nutritional Impact: Milk, cheese, and meat from domesticated animals provided major sources of protein and fat, supplementing carbohydrates and protein from grains.
  • Result: Fertile Crescent offered all necessary nutrition for a new life based entirely on agriculture.

Geographic Spread of Agriculture (fig. 7.2)

• Tracing the Spread: Marked by the first occurrence of domesticated cereal and legume grains in radiocarbon-dated lake sediments in regions where these plants did not grow wild.
• Early Expansion:
  • By $9,000$ to $8,000$ years ago: Fertile Crescent crops reached eastward into India and westward into modern-day Greece.
  • By $7,000$ years ago: Spread southward into Egypt and Tunisia, westward into southern Italy and Spain, and northward into Germany.
  • By $6,000$ years ago: Farming was present in all of Europe where it is practiced today.
• Pace of Spread: Slow regionally, but often rapid on a site-by-site basis.
• Adaptation to New Climates: Cereals and crops adapted to semi-arid climates thrived abundantly in the moisture-rich climate of Europe.
• Regional Livestock Differences: Wild cattle and pigs (boars) were plentiful in central and northern Europe, becoming primary domesticated livestock there, unlike the goats and sheep common in southern Europe.

Independent Agricultural Developments in Other Regions

• Southeast Asia (Second Major Origin Region): Spans diverse environments.
  • Northeastern China (Yellow River floodplain, arid west):
    • Grew two kinds of millet; earliest remains $9,500$ years ago.
    • Associated with bones of domesticated chickens and pigs, stone tools, and pottery.
  • Tropical Southern China, Burma, Thailand (warmer, wetter regions):
    • Rice farming developed in steps, starting prior to $8,000$ years ago with gathering wild strains.
    • Intentional planting over the next two millennia.
    • Early farmers likely poked holes in moist ground to plant.
    • By $5,000$ years ago: Controlled irrigation of rice fields began.
• Indus River Valley (western India):
  • $9,000-8,000$ years ago: Distinctive Fertile Crescent crops arrived.
  • Locally domesticated crops like cucumbers and sesame added.
• Ganges Delta (east-central India):
  • By about $3,000$ years ago: Rice-farming techniques from Southeast Asia arrived.
• The Americas:
  • Squash grown almost $10,000$ years ago.
  • Avocados, beans, and corn by $9,000$ to $7,500$ years ago.
  • Potatoes and tomatoes also domesticated.
  • Corn (Maize) Domestication Example: A strikingly successful, slow process of human plant selection.
    • Wild predecessor (Teosinte) had tiny ears ($1$ inch / $2-3$ cm).
    • Millions of individual farmer decisions over several thousand years to select and plant kernels from larger forms resulted in modern-sized corn.
  • Other American Crops: Cotton, potatoes, peanuts, several kinds of beans domesticated and cultivated.
  • Achievement: Early Americans' cumulative plant selection rivaled Eurasia.
  • Animal Domestication Challenge: Animals suitable for domestication and harnessing were rare, partly due to extinctions nearly $12,500$ years ago.
    • Llama and alpaca: Suitable for wool and occasionally as pack animals, but no large draft animals (like horses and oxen).
  • Large-Scale Forest Clearance: Occurred in the Yucatan Peninsula (Central America) after $3,000$ years ago for agriculture (Mayan civilizations).
    • People double-cropped plants in raised fields among swampy lowlands.
  • Amazon Basin: Recent investigations confirm surprisingly large farming populations just prior to European arrival.
• Africa and New Guinea: Agriculture began early and independently.
  • Tropical rainforests and savannas yielded millet, oil palm, sorghum, and peas.
• Western South Pacific:
  • After $3,800$ years ago: Influence of southern Chinese agriculture and culture spread across Polynesia in two phases.
  • Brought breadfruit, yams, potatoes, taro, bananas, along with dogs, chickens, and pigs via ambitious sea voyages.

The Impact of Agriculture: Rise of Civilizations and Environmental Transformation

• Expanding and Diversifying Impact (Beginning ~$6,000$ years ago):
  • Textile and Utility Plants: Fibrous plants like flax, cotton, and hemp grown for clothing, blankets, and rope.
  • Animal Products: Wool from sheep, goats, llama, alpaca; leather from cattle; silk from silkworms.
  • Containers: Bottle gourds for carrying water.
• Spurring Civilization Growth (Major Threshold): Agriculture and other innovations initiated the growth of major civilizations, which in turn significantly impacted the environment.

Metallurgy: Leaving the Stone Age

• Early Observations: Probably began with simple observations around campfires: rocks lining hearths sometimes contained shiny metal veins that melted at low temperatures, flowed out, and solidified.
• Metal Extraction: In some regions, pure metal veins were apparent in rock outcrops.
• Technological Leap: The next obvious step was to melt and refine copper and tin, and later the alloy they created.
  • Bronze Age: Initiated $6,000$ to $5,500$ years ago in northern China. (By Roman times, metals were also used in tools, weapons, and currencies.)
  • Iron Age: Started by $3,300$ years ago in southern China.

Labor Transformation and Irrigation

• Domesticated Draft Animals (Nearly $6,000$ years ago): Water buffalo and horses were domesticated.
  • Provided much greater power for pulling plows than humans.
  • Result: Farming labor transformed, allowing ever-greater areas to be plowed and brought into production.
• Widespread Irrigation:
  • Primitive canals: In modern-day Turkey, dating back to $8,200$ years ago.
  • Spread: Down into the Tigris-Euphrates River valleys between $7,300$ and $5,700$ years ago.
  • Significance: Freed farmers from reliance on unpredictable river flooding (too little or too much water, erosion).
  • By $4,000$ years ago: Wide use in rice-growing regions across Southeast Asia.

Continued Technological and Agricultural Innovations

• The Wheel: Invented nearly $6,400$ years ago (west of the Black Sea), spread throughout Eurasia by $5,000$ years ago.
• Orchards (By $5,500$ years ago): People learned to plant cuttings or seeds for olives, figs, dates, and grapes. Later, using grafting, they planted apples, pears, cherries, and plums.
• New Domesticated Crops: Former