Guns, Germs and Steel Chapter 7 QS: Due 10/27


1. What is DiamondŐs definition of domestication?

Ňgrowing a plant and thereby, consciously or unconsciously, causing it to change genetically from its wild ancestor in ways making it more useful to human consumers.Ó 


2. Why is animal dispersal not domestication?

It doesnŐt involve humansŐ conscious or unconscious selection.


3. What 5-6 criteria did early humans look for when selecting plants? size, tastiness, fleshiness (fruits), oily seeds, long fibers.


4. South, west and north of Chico, farmers grow almonds on thousands of acres that used to provide resources for indigenous hunters and gatherers.  Having read Ch. 7, explain how that is amazing. Use the terms in your explanation: cyanide, mutation, watermelon.

The seeds of wild almonds produce a compound, amygdalin that is bitter and which the human digestive system can break down into cyanide, a poison. A single gene mutation in an almond tree prevents the production of amygdalin and results in sweet-tasting almonds. These mutants are the ancestors of the almond trees that fill orchards in so much of the Central Valley.  Humans domesticated other bitter or poisonous plants, including the watermelon.  We value it for its sweetness, but in its wild, natural state it is bitter or poisonous.


5. What four changes did early farmers/domesticators make to plants that were not visible to them? 1. Selection of non-popping pea mutants; and 2. non-shattering wheat and oat plants; 3. Sow-grow-harvest-grow cycle favored plants which had thin seed coats and lacked germination inhibitors; 4. selected for mutants that developed seeds without pollination and/or hermaphrodites that could pollinate themselves. 


6. What is a hermaphroditic plant? Why is it important to domestication?

Hermaphroditic plants have both male and female reproductive organs. In a wild setting, many plants depend on cross-pollination for production of fruit or seed. Hermaphroditic plants that can pollinate themselves were important to early farmers because they would not lose, through cross-pollination, the features selected by humans.


7. What commonly eaten plants were all developed from cabbage?

cabbage, kale, kohlrabi, brussel sprouts, cauliflower, broccoli


8. What were the three stages of domestication? Identify some of the plants domesticated during each stage.

1. Wheat, barley, peas (annual cereal plants) from Fertile Crescent. Productive as wild plants, easily grown, easily stored, self-pollinated, little genetic change from wild to domesticated.

2. First fruit and nut trees: olives, figs, dates, pomegranates, grapes. Required several years to produce, but could be grown easily: vegetatively or by seed.

3. Trees such as apples, pears, plums and cherries. More difficult because they canŐt be grown from cuttings, nor easily from seed.  Instead they have to be grafted, which is much more difficult.   


9. Why does Diamond spend so much time talking about cereal/pulse combinations?

Diamond emphasizes cereal/pulse combinations because early agriculture often was based on a high carbohydrate cereal and a high protein pulse: Wheat and peas in the Fertile Crescent, maize and beans in Mesoamerica, rice and soybeans in China.


10. Why did New World farmers sow multiple plants in a garden with sticks instead of using a plow and planting only one plant in a field?

New World farmers did not have large domesticated draft animals that could pull a plow. So, farmers planted seeds of several food plant species in holes that they made with sticks.


11. Why have humans not domesticated oak trees for food?

1. slow growth of trees.

2. squirrels.

3. oak acorn bitterness is controlled not by a single gene, like almonds, but by many genes.