Transcript Origin of Agriculture

Origin of Agriculture
Introduction
• Knowledge of time and place of origin is
important
– For taxonomists and plant breeders
– Present day plants are much different than the
wild varieties
• Genetically and morphologically different
• Several genes (characterisitcs) are selected
– Loss of plants is loss of gene pools from
which new traits can be retrieved
Introduction
• Humans turned non-agricultural to
agricultural way of life.
• Agriculture; horticulture and domestication
• Study history by
– Carbon dating
– Fossils
– Phytoliths
Why farm?
• Work by Lee and Devore
– !King bushmen of Kalahari desert of southern
Africa
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Selected plant for adequate diet
105 species were used
Did not work hard
Not due to mal-nutrition or poverty
• Not revolution but evolution
De Candolle (1883)
• Pioneering work
• Criteria for recognizing centers of origin
– Places where a plant grows spontaneously in
a wild state
– Places where fragments of plants in old
deposits and buildings (archeological and
palaeobotanical) are found
– Archives describing the adventures of
travelers.
– Philogical (naming) origin
Vavilov (1927)
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Center located in 20-45 degrees latitude
6-8 centers
China
India
Central Asia
Near East
Mediterranean
Ethiopia
Mesoamerica
South America
Zhukovsky (1968)
• Megagene centers
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China
Indochina - Indochina
Australia - New Zealand
India
Central Asia
West Asia
Mediterranean
Africa
Europe - Siberia
Mexico & Central America
N. America
Centers of Origin
• Primary center: Places where initial
formation of species has taken place
• Secondary centers: new species formed
due to mutations and hybridization. Has
wide variety of subspecies
Harlan (1971 and 1992)
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Centers and non-centers: three each
Recently related biomes to cultivation
Tundra – no cultivation
Tropical: Sugar cane, banana, orange, mango
and cocoa. Root crops and coffee
• Temperate: cheery, apple, pear, grapes walnut,
millets and wheat
• Mediterranean: maize, rice, sorghum, cassava,
sweet potato, bean, peanut, yams
• Sea coast: coconut, cabbage, cotton, beet
Old World Centers
• The near east: 9,000 – 14,000 years ago.
Fertile crescent of Mesopotamia. Wheat,
barley, peas and vetch
• The far east: 7,000- 8,000 years ago.
China, Thailand, India. Rice, millet, rape
and hemp
New World Centers
• Eastern North America: Cherokee
Sunflower and cranberries
• Western North America: Pueblo Dwellers
Trees and shrubs; pine nuts and pigweed
• Mexico: Aztecs and Mayans; Corn and
beans
• South American: Inca; Potato and
chocolate
Agriculture to day
• 3% of land is used for cultivation
• US: 1.9 billion acres
– 310million acres for crop
– 650 million acres for animal
• Four major crops: 80% Corn, wheat soy
and hay
• All fruits and vegetable – 7% land
• Cotton – 4%