The Columbian Exchange
Before 1492
Two very
different
ecosystems
Two different
disease pools
Two sets of
culturally
diverse
peoples
Two sets of
flora and fauna
“...all the trees were as different
from ours as day from night, and
so the fruits, the herbage, the
rocks, and all things.”
-- Christopher Columbus
Two biological ecosystems interchanged
to create a new world ecology.
According to historian
Alfred Crosby, the
exchange of plants,
animals and
pathogens between
the two hemispheres
was biologically “the
most spectacular
thing that has ever
happened to humans,"
and he coined the
phenomenon the
Columbian Exchange.
An Exchange of Pathogens
The smallpox virus
A Demographic Collapse
Aztecs afflicted with Smallpox
In Mexico alone, the native population fell from
roughly 30 million in 1519 to only 3 million in 1568.
Modern-day
victims of
smallpox
Livestock
A Plague of Sheep
Chickens and Eggs
The Cowboys of the Americas
Vaquero
Gaucho
Llanero
Cowboy
The greatest impact of the
Columbian Exchange was the
exchange of different food crops.
Sweet
Potatos
Cassava
Potatos
The Exchange of Plants and Animals
Originally from the Western Hemisphere
• Potato
• Maize (corn)
• Manioc (cassava, tapioca)
• Sweet potato
• Tomato
• Cacao (chocolate)
• Squash
• Chili peppers
• Pumpkin
• Papaya
• Guava
• Tobacco
• Avocado
• Pineapple
• Beans (most varieties, including
phaseolus vulgaris)
•
•
•
•
Peanuts
Certain cottons
Rubber
Turkeys
Originally from the Eastern Hemisphere
• Sugar
• Olive oil
• Various grains (Wheat, rice, rye,
barley, oats)
• Grapes
• Coffee
• Horses
• Cattle
• Pigs
• Goats
• Sheep
• Chickens
• Various fruit trees (pear, apple,
peach, orange, lemon, pomegranate,
fig, banana)
• Chick peas
• Melons
• Radishes
• A wide variety of weeds and grasses
• Cauliflower
• Cabbage
An Increase in Food Supply
Helped Populations to Rise
The eventual result of all the exchanging of different food
crops was a dramatic increase in food supply, which in turn
caused a rise in population. How and why did this happen?
An entirely new food plant or set of food plants permits the
utilization of soils and seasons that have previously gone
unused, thus causing a real jump in food production and,
therefore, population. The benefits went both ways.
Some Tropical Plants from the
Old World
Some Tropical Plants from
the New World
Maize/Corn
Sugar, Tobacco and Slavery
Africans lament the loss of
their fellow countrymen.
MAP 26.2 The Atlantic slave trade, 1500-1800.
The Potato
The potato grows
well in the
temperate climate
of northern Europe
and produces three
times as much food
per unit of land as
wheat or any other
grain.
The Poor Person’s Food
The Bank of England
Between 1781 and 1845, the Irish population doubled
from four to eight million. Probably half of this
population depended on the potato for survival.
The Great Irish Famine
Over one million died of starvation and
disease, and almost two million emigrated to
the United States and Britain.
The Columbian Exchange
The effects of the columbian
exchange are still with us today.
Bit by bit, we are becoming more homogenized,
and the world is becoming smaller.
Is the world growing more the same?