Chapter 11

The Lethal Gift of Livestock

Farmer Power

• Farmers have greater numbers than hunter/ gatherers – 10 or 100 to 1

• Own better weapons and armor• Have more powerful technology• Have centralized governments with

literate elites – better able to wage wars of

conquest• Breathe out nastier germs.

Major Killers

• Major killers of humanity throughout recent history are all infectious diseases that evolved from diseases of animals– Smallpox– Flu– Tuberculosis– Malaria– Plague (pictured)– Measles– cholera.

Disease victims in war• Until WWII, more victims

of war died of disease than battle wounds.

• 95% of Native Americans died from diseases brought by Europeans.

• Why not the other way around?

• Europeans had the animals and the large populations that produced the diseases.

How Diseases Spread

• Passively – Salmonella

• insect vector– Malaria

– Plague

– Typhus

– Sleeping sickness

• Lesions– Syphilis

– Smallpox

How Diseases Spread• Coughing

– Flu

– Cold

– Whooping cough

• Diarrhea

– Cholera

How Diseases Spread

• Killing humans is an unintended byproduct of disease growth and spread

How We Respond to Diseases

• Fever (bake out microbe)

• Immune response.

– This may give us lifelong immunity (measles, mumps, rubella, pertussis, smallpox)

– or not, if microbe evolves quickly (flu, malaria, sleeping sickness, AIDS)

• Natural selection.

– Not everybody dies, resistant genes selected for in population.

Children with AIDS

Epidemic Diseases

• Epidemic diseases spread quickly to an entire population

• Run their course quickly

• Result in either death or resistance.

• Tend to be restricted to humans.

– ex: measles, rubella, mumps, pertussis, smallpox

Smallpox

Epidemic Diseases

• Flu killed 21 million people at end of WWI.

• Black Death killed 1/4 of Europe's population between 1346 and 1352.

• Disease dies out if population is under a half million because everybody has been exposed and is either dead or resistant. Plague, 14th Century

Europe

Epidemic Diseases

• Disease only survives with travel between populations or between uninfected pockets within a population.

• These diseases cannot sustain themselves in small populations of hunters/gatherers

Diseases in Small Populations

• Dysentery from a sailor on a whaling ship killed 51 of 56 Sadlermiut Eskimos in 1902.

• Then disease died out.

Diseases in Small Populations

• Diseases in small populations restricted to

– ones that can live in animals:

• yellow fever

– ones that take a long time to kill:

• leprosy

– ones that humans don't develop immunity to.

• worms and parasites

Leprosy

Agriculture and Disease

• Why did agriculture launch the major infectious diseases? – high human

populations– Sedentary life among

sewage– Close proximity to

herd animals

Disease Transfer from Animals

• Four stages of animal to human disease transfer:• 1) diseases directly from animals.

– Don't get transmitted human to human – ex: brucellosis from cattle, leptospirosis from dogs

• 2) Does transfer human to human, but dies out – ex: Fort Bragg fever in 1942

• 3) Transfers human to human but not yet long-established – ex: Lyme disease, AIDS

• 4) long established epidemic diseases. – Diseases evolve to effectively work in new host – ex: syphilis

Role of Disease in Conquest

• Diseases played huge part in conquest of New World.

• Hispaniola had 8 million inhabitants in 1492, zero by 1535.

• There were estimated 20 million Indians in USA before European diseases. 19 million died

Role of Disease in Conquest

• Were 20 million in Mexico, reduced by disease to 1.6 million.

• With 20 million, why not more infectious diseases?

• Answer: No large domestic animals.

Chapter 12

Blueprints and Borrowed Letters

Writing

• Writing marched together with weapons, microbes and centralized political organization as a modern agent of conquest.

• Why did only some peoples and not others develop writing, given its overwhelming value?

Pizarro’s conquest of Atahuallpa

Strategies for Writing

• Three strategies for writing:

• 1) logogram– One symbol stands for a word

• Ex: Chinese

• Syllabary– One symbol stands for a syllable

• Alphabet– One symbol stands for a basic sound

Chinese

Invention of Writing

• Writing invented independently just four times

– Mesopotamia (3,000 BC)

– Egypt (3,000 BC)

– China (1300 BC)

– Mexico (600 BC)

• All others borrowed, adapted or inspired by these systems.

Egyptian hieroglyphics

Invention of the Alphabet

• Alphabet invented just once: by Semites starting 1700 BC

• Three steps in Alphabet development:

– Started with 24 Egyptian consonants, discarded all logograms

– Ordered the consonants in fixed sequence

• Greek: Alpha, Beta, etc. gave Alphabet its name

– Invented vowel symbols

“Blueprint” Copying

• “Blueprint” copying of Semitic alphabet (with modifications) led to these alphabets:

– Aramaic, Southeast Asian

– Persian, Phoenician

– Arabic, Greek

– Hebrew, Roman

– Indian, Cyrillic

“Idea Diffusion”

• Writing systems have also spread by “idea diffusion”

• Ex: Cherokee Indian named Sequoyah, 1820s– Illiterate– Devised a writing system for

Cherokee language – Was a syllabary of 85

symbols– Based only on knowledge that

English could be writtenSequoyah

“Idea Diffusion”

• Other writing systems originated by “idea diffusion”:– Korean

– Celtic Ogham

– PolynesianKorean alphabet: 24 letters

Early Writing

• Early writing was like shorthand– For record keeping– Required Scribes to write

• Arose in stratified societies that could support bureaucrats

• Hunter/Gatherers – No use for scribes– No extra food to feed scribes

• Since most societies acquired writing from others, isolated complex societies less likely to have it:– Incas– Sub-Saharan Africa– Native Americans in Mississippi valley

Egyptian scribe

Chapter 13

Necessity’s Mother

Technology

• Why did technology evolve at different rates on different continents?

• Many inventions are the mother of necessity– Without a clear need– In search of practical application– Or their application evolves

• Automobiles were not “needed” at first: toys of rich

• Phonograph was not for music: Edison objected!

             

              

Tinkering

• Inventors have to tinker for a long time for inventions to be accepted– TV

– Cameras

– Typewriters

Inventions

• Inventions rest on a long history of previous inventions:– James Watt’s steam engine

(1769) – Was based on Newcomb’s

(1712)– Which was based on

Savery’s (1698), etc.

• Therefore, if not Watt, would be someone else

Acceptance by Society

• Inventions depend on society being ready to accept or exploit the invention

• Four Factors influence acceptance:– 1) economic advantage – 2) social value and prestige– 3) vested interests

• QWERTY typewriters designed to slow down typing for 1870 typewriter

• Once widely accepted, can’t change although very inefficient

– 4) ease of observing advantages• English immediately saw

advantage of cannonsQWERTY keys once an advantage

Resistance to Technology

• For any given society, most inventions come from elsewhere – either accepted or not

• Many reasons societies resistant to technology adoption

• Each continent has more and less resistant cultures

• Reception to technology varies over time in the same culture– Japan adopted firearm technology in

1540s– improved them and became best in the

world– then banned them by 1600s.

Acceptance of Technology

• Societies accept technologies because:

• They see an advantage• Conquered by others

with technology• Invention spreads by

“Idea Diffusion”– Porcelain china

manufacture in EnglandBritish Porcelain China

Autocatalysis

• Technology begets more technology: Autocatalysis– Current rate very fast

• Reasons:– Advances depend on

previous mastery of simpler problems

• Ex: Metallurgy from copper to iron

– Combinations of technologies make new technologies possible

• Ex: Printing Press

Technology Development

• Three Factors in Technology Development:

• 1) Time of onset of food production

• 2) Lack of barriers to diffusion (isolation)

• 3) Human population size

• Huge advantage of Eurasia in all three areas!