Diffusion Plants Animals and Diseases Ronald Wiltse September
Diffusion: Plants, Animals, and Diseases Ronald Wiltse September 2006
I. Types of diffusion A. Natural (“biodiversification”—Alfred Crosby) 1 Spread of plants by wind and bird 2 Spread of diseases from one species to another
I. Types of diffusion B. Human caused —Alfred Crosby) 1 purposeful 2 accidental (“diffusion”
II. Contacts between closed areas A. Migration B. Trade C. Conquest D. Exploration
III. The closing of the world Community
IV. Examples A. Ancient B. Islamic Empire C. subsequent to the discovery of America D. Recent examples
A. Ancient rice (Pakistan, to China and Japan; to medieval Europe) wheat (SE Turkey, to S Asia, Nile, Greece by known in this time) 6000, to China by 2000 BC; the Western Hemisphere at
carrots (Afghanistan to Spain to Medieval Europe) citrus fruit (India to Iberian Peninsula) B. Islamic Empire (“The Islamic Exchange”) cotton (brought to Europe ca AD 800) okra (Africa to India) sugar cane (Polynesia to China and India, ca. 1000 BC; to Egypt, Iberian Peninsula)
B. Islamic Empire (“The Islamic Exchange”) 1 land use in Spain at the time of the Islamic conquest a. Roman “natives” grew wheat, grapes, barley, olive oil, and a few vegetables.
B. Islamic Empire (“The Islamic Exchange”) 1 land use in Spain at the time of the Islamic conquest b. The Visigothic rulers preferred herding.
B. Islamic Empire (“The Islamic Exchange”) 1 land use in Spain at the time of the Islamic conquest c. The new overlords wanted to introduce new plants which required more water;
B. Islamic Empire (“The Islamic Exchange”) 1 land use in Spain at the time of the Islamic conquest c. thus, they built irrigation systems. Central to these systems were. . .
B. Islamic Empire (“The Islamic Exchange”) 1 land use in Spain at the time of the Islamic conquest c. . norias, waterwheels which used the power of flowing water to raise some of the water to a higher level.
C. Subsequent to the discovery of America 1 Plants a. From the Eastern Hemisphere cotton (but already known in the Western Hemisphere) onions
C. Subsequent to the discovery of America 1 Plants a. From the Eastern Hemisphere rice (to South Carolina, 1685) sugar wheat
C. Subsequent to the discovery of America 1 Plants b. From the Western Hemisphere avocados maize (corn) white potatoes sweet potatoes tomatoes
C. Subsequent to the discovery of America 2 Animals a. From the Eastern Hemisphere new varieties of dogs horses donkeys pigs cattle goats sheep barnyard fowl
C. Subsequent to the discovery of America 2 Animals b. From the Western Hemisphere nothing significant
C. Subsequent to the discovery of America 3 Diseases a. From the Eastern Hemisphere bubonic plague cholera malaria
C. Subsequent to the discovery of America 3 Diseases a. From the Eastern Hemisphere measles smallpox (note spread in North America, culminating in 1779 -1780 among Plains Indians, due to the rise of mobility caused by the introduction of horses, over the preceding century)
C. Subsequent to the discovery of America 3 Diseases b. From the Western Hemisphere perhaps none (why so few in the Western Hemisphere? Perhaps it is because of the lack of propinquity to barnyard animals).
D. Recent examples P = purposeful, A = accidental, PA =import purposeful, spread accidental, N = natural, i. e. , no human interaction
P = A = PA = N = purposeful, accidental, import purposeful, spread accidental, natural, i. e. , no human interaction D. Recent examples 1. Russian thistle (tumbleweed) A from Russia to US
P = A = PA = N = purposeful, accidental, import purposeful, spread accidental, natural, i. e. , no human interaction D. Recent examples 2. Kudzu PA from Japan to US 1876 Centennial Exposition, Japanese exhibit ► 1920 s Florida nursery sells it as a source of animal feed
P = A = PA = N = purposeful, accidental, import purposeful, spread accidental, natural, i. e. , no human interaction D. Recent examples 2. Kudzu ► 1930 s Soil Conservation Service promotes kudzu as an erosion fighter (“the miracle vine”) ► 1972 USDA declares kudzu a weed ► 2050 s government of the US collapses as kudzu covers 90% of US
P = A = PA = N = purposeful, accidental, import purposeful, spread accidental, natural, i. e. , no human interaction D. Recent examples 2. Kudzu PA from Japan to US 1876 Centennial Exposition, Japanese exhibit ► 1920 s Florida nursery sells it as a source of animal feed
P = A = PA = N = purposeful, accidental, import purposeful, spread accidental, natural, i. e. , no human interaction D. Recent examples 3. Killer bees P from Africa to Brazil, N to the US 4. Armadillo N Central America to US
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