Cultivation - first step - encouragement of growth of useful plants

Domestication - Selection of particularly useful individuals that results in genetic alternation of plants, would be logical followup of cultivation.

Human have existed for about 100,000 years.

When did agriculture begin?

Evidence - Plant and animal remains in garbage dumps
Pollen grains found on pots, pollen grains are useful because of
1. resistance to decomposition
2. have features which often allow identification of plant.

Dating is done by C14 method - measuring ratios of C12/C14 - works for 500-50,000 years bp. Equilibrium betwen C14 and C12 in atmosphere is constant, once organism dies, does not take up anymore C14 and C14---->C12.

Earliest sites for agriculture are in the Fertile Crescent but there is debate that agriculture began at about the same time independently in Central America and Asia. Time is generally given as 10,000 ybp.

Ratio of 10,000 years to age of earth is 1/400,000.

Myths of origin of agriculture have developed and one thing that is common is that agriculture is a gift from the gods. One exception is Judeo-Christian version in which agriculture was a burden imposed on mankind due to original sin.

There is evidence that nonagricultural peoples knew how to grow plants. Why did human culture decide to adopt agriculture? Recent studies of so-called primitive hunter-gatherer tribes indicate that people in these societies do not have to work harder to obtain adequate food than primitive agriculturalists. There is some indication that they have to work less, live longer and are less subject to famine. Current ideas are that humans had developed a sedentary lifestyle before adopting agriculture and didn't until they had to
- Stress from population increases - no evidence of correlation.
- Pressure from climatic changes.

Origins of crops - Nikolay Vavilov

Centers of origin
1. Areas where wild relatives occur are likely sites of originial domestication.
2. Great amounts of natural variation in crops grown in centers.

Eight major centers of crop domestication.
1. Chinese - apple, onion, peach, soybeans
2. Indian Center
A. Main Center - rice, organge, sugar cane, pepper
B. Indo-Malayan Center - banana
3. Central Asiatic Center - wheat, pea mustard, cotton, carrot, grapes
4. Near Eastern Center - wheat, rye, oats, alfalfa, cherry
5. Mediterranean Center - wheat, beet, lettuce, spice plants
6. Abyssinian Center - wheat, sorghum, coffee
7. South Mexican and Central American Center - maize, amaranth, cotton, cherry tomato, sweet potato, pepper
8. South American Center - potato, lima bean, tomato, pepper, tobacco, peanut, pineapple, cashew

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