Guns Germs and Steel
Chapter 7: How to Make an Almond
Selection of Desired Qualities
In nature, fruits are often fleshy to attract animals
the seeds of fruit are often bitter and are dispersed (and fertilized)
by passing through the animal.
Domestication of plants by humans also may have started in such latrines.
Eventually humans selected desired qualities:
Traits Selected Unknowingly
lack of bitterness
fiber length in plants.
Difficulty of Domestication
Dispersal mutations (peas that stayed in the pods, wheat that did not shatter)
Early germination of planted seeds -- those that did not readily germinate
were not selected for replanting (examples wheat, barley, peas)
Reproductive biology to be selfing (plums, peaches apricots, cherries,
Seed size: competition among planted seeds selects for qualities like seed
size differently than in nature.
Wheat and peas easy to domesticate in Fertile Crescent (8,500 B.C.)
Fruit and nut trees harder to domesticate(4,000 B.C.) due to long
Fruit trees that needed grafting took even longer
Cereals are low in protein, but the deficit is made up by pulses (beans,
peas, lentils) in most food systems.
Sowing by Broadcast
Grains in Eurasia were sown by broadcast, later in animal plowed fields
to give monoculture.
In new world, planting done by digging stick, (no plow animals domesticated),
leading to mixed gardens.
Almonds and Oaks
Almonds more easily domesticated:
Oaks never domesticated:
Only one gene for bitterness of seed.
fast squirrels replant acorns
multiple genes controlling bitterness.
Chapter 8: Apples or Indians
There are 200,000 species of plants
Only a dozen account for 80% of worlds production:
Wheat, corn, rice, barley, sorghum, soybean, potato, cassava, sweet potato,
sugar cane, sugar beet, banana.
All of these domesticated thousands of years ago.
No new plants domesticated in modern times
Several domesticable plants had large ranges, but domesticated
only in one place.
Why not in others?
Domestication required settling down, and had to be worth it with several
plants domesticated, not just one.
Fertile Crescent Attributes
Abundant wild stands of wheat that needed little change to be domesticated.
Hunter/gatherers settled down here before agriculture, living off grain
High percentage of self pollinating plants -- easiest to domesticate.
Fertile Crescent Advantages
Fertile Crescent Domestication
Largest Mediterranean climate with highest diversity of species.
High percentage of annual plants. Annuals produce seeds that dry down until
rainy season. Of large seeded grass species of the world, 32 of 56
Diversity of terrain and habitats: diversity of species to be domesticated.
Big animals for domestication: goat, sheep, pig, cow.
Agriculture launched by domestication of 8 crops (founder crops): emmer
wheat, einkorn wheat, barley, lentil, pea, chickpea, bitter vetch, flax.
Wheat and pulses gave balanced carbohydrate and protein.
Hunter gathering eventually not too productive, easily giving way
Domestication occurred from 9,000 B.C. to 6,000 B.C.
In Meso America, the only animals domesticated were turkey and dog
Maize was slow to domesticate.
Domestication occurred from 3,500 B.C. to 1,500 B.C.
In New Guinea or USA, food also independently domesticated, but limited
Indigenous peoples usually walking encyclopedias about wild foods.
Was it culture that rejected domesticated crops?
Unlikely since imported crops readily adapted and then populations
Problem was in the plants available for domestication.
Poor candidates for grain domestication
No large animal domestication,
Crops domesticated had limited calories and protein.
New Guinea crop was Taro:
Low in protein, leading to eating of
USA crops were squash, sunflower, sumpweed and goosefoot.
Not enough of a crop package to sustain large populations without
hunting and gathering, until Maize imported 2000 years later.
Therefore it was the lack of an entire suite of animal and plants
available for domestication that was responsible for the late start of
food production in N. America.
Chapter 9: Zebras, etc
Of the 14 large (over 100 lb) successful domesticated animal species
in the world
13 are from Eurasia,
one from South America.
Why the huge disparity?
Why did Africa have none?
Of 148 large herbivorous or omnivorous species in the world
Not a Cultural Issue
Eurasia had 72
When the big 5 Eurasian domesticates (Cow, sheep goat, pig, horse) were
introduced into Africa and the Americas they were readily adopted.
All peoples have experience taming wild animals, keeping pets. But
not all tamed animals can become domesticated.
All major animal domestication occurred between 8,500-2,500 B.C. with almost
none since then.
Those of the 148 possible species capable of being domesticated were domesticated.
Some species like cows, dogs, pigs independently domesticated in different
parts of the world. These animals were well suited for domestication.
Modern attempts to domesticate eland, elk, moose, musk ox, zebra, American
Bison are only marginally successful.
Why have 134 out of 148 big species not been domesticated?
1) Diet too finicky (ex: koala)
2) Growth rate too slow (ex: elephants, gorillas)
3) Captive Breeding. Some animals have elaborate mating rituals that
they won't do in captivity (ex: cheetah, vicuna)
4) Nasty Disposition. (ex: grizzly bear, African buffalo, onager, zebra,
5) Tendency to panic. (ex: deer, antelope, gazelles).
6) Social structure.
Need animals that live in herds with hierarchy and have overlapping ranges
Humans can then take over dominance position.
Solitary animals hard to domesticate (only cats and ferrets have
Territorial animals hard to pen up with others (ex: Africa antelope, rhino).
Animals without dominance structure are hard to herd (ex: deer, antelope.
Chapter 10: Spacious Skies and Tilted Axes
Easier to spread East-West
It was easier for domestic plants and animals (later, technology like
wheels, writing) to spread East-West in Eurasia than North- South in Americas.
Some crops (lima beans, common beans, chili peppers) domesticated
independently in both S. America and Meso America due to slow spread
Most crops in Eurasia domesticated only once.
Rapid spread preempted same or similar domestication. Fertile Crescent
crops spread to Egypt, N. Africa, Europe, India and eventually to China.
East-West spread of plants, animals easier due to same day-length,
similar seasonal variations.
By contrast, spread of these crops stopped past Sahara due to tropical
climate, and thus didn't reach temperate S. Africa until colonists came.
Tropical crops spread West to East in Africa with Bantu culture, but did
not cross to S. Africa due to climate.
Amber Waves of Grain
Distance between cool highlands of Mexico and Andes was only 1,200
miles but separated by low hot tropical region.
Thus, no exchange of crops, animals, writing, wheel.
Only maize spread.
It took 2,000 years for maize to cross 700 miles of desert to reach U.S.A.
It took another 1000 years for maize to adapt to U.S.A. climate to be productive.
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Food Issues Webpage
Geographic barriers like mountains and deserts can also slow spread
of crops East-West
agriculture spread from U.S.A. southeast to southwest slowed by dry Texas
and southern great plains
Amber waves of grain did not stretch from sea to sea in N. America, but
did in Eurasia.
Not a Cultural Issue