January 16, 2002
Global Change 2
The Cultural Transformation of the Environment II
The major change in human history that effected the environment was the beginning of
domesticated plants and animals. These events, independent in various places in the
world after 12,000 years ago resulted in agriculture, an increase in predictable food
supplies and a rise in the human population.
To understand domestication we must examine the ecosystem and humans as biological
populations.
OVERHEAD #7 A Simplified Ecosystem
The ecosystem is the interrelations among populations of organisms and their abiotic
environment. We can delimit the ecosystem by tracing the flow of energy through the
system of interconnected parts.
Primary producers are the green plants. The chemically convert solar radiation , water
and dissolved minerals and chemicals into food. They consist of many plants within an
ecosystem.
Consumers are the animals that browse or graze upon the plants. As we examine each
level in the ecosystem the amount of food available diminishes because of heat loss from
respiration, search movement to get the food, and inefficient digestion. Consumers are
deer, mammoths, cows, sheep, pigs, llamas, etc.
Omnivores consume plants and animals. There numbers are controlled by the relative
amount of each that they consume. Human hunters and gatherers (bands) have smaller
numbers because of mobility to reach the plants or to search for animals. Sedentary
farmers (tribes/chiefdoms) have greater numbers because their food (calories) comes
from staple crops supplemented with animal products. Beyond humans omnivores
include coyotes, bears, raccoons.
Predators eat consumers but as you would expect there numbers are fewer yet. These
would include wolves, lions, and tigers.
Higher predators would be those at the top of the food pyramid like eagles and hawks.
As these organisms die fungi, bacteria, worms, and other organisms that comprise the
detritus organisms consume them. These are essential for decomposing organic
material within the ecosystem and for recycling geo-chemicals. Their by-products go
into the soil where they are dissolved in moisture and are available to the roots or hyphae
of other organisms.
With the advent of agriculture humans transformed ecosystems and with population grow
them dominated them to the extent that they created new ones by substituting
domesticated plants and animals in the areas once occupied by wild organisms. A
consequence of agriculture was the domination of ecosystems by humans. At the local
level this happened before the rise of states or cities.
SLIDE #1: Plant Husbandry and Production
Humans manipulated plants by a number of means. The gathered them with little change
in their abundance or future availability. They also cultivated them. This is the human
intervention in the annual life cycle of plant species to increase abundance or the yield of
a particular product, e.g., fruit or nuts. Methods of cultivation include the use of fire to
stimulate plant growth, weeding out competitors, sewing seeds, tilling the soil to aerate it
and oxidize chemicals that could hinder plant growth, or transplant them to new areas.
Humans made new ecosystems by creating gardens. These are human defined spaces
with growing plants that normally would not be found together. Humans could control
these spaces through hunting or by regulating resources needed for plant growth, e.g.,
water. Within gardens mutations to plants would be observed and might be preserved by
humans as a form of incipient domestication. We expect that gardens were the source of
the first domesticated plants and women probably discovered them.
Domesticated plants and animals are artifacts. They do not occur in nature and are a
product of human genetic manipulation. Most cannot reproduce without humans and all
would become extinct if humans did not maintain them across the generations.
With domestication and the need to perpetuate these predictable and highly productive
plants and animals, the landscape was further changed. Some could be planted in fields.
Animals could be raised in pastures. New varieties could be formed as a consequence of
raising them in unique habitats where new mutations might arise or cross-breeding
happen to produce new forms.
The first domesticated animal was the dog. It evolved from the wolf in the Upper
Paleolithic in the Near East. It was used for protection and for hunting.
The first domesticated plant was the bottle gourd. We find it as the baseline plant in
South America, Africa, and Southeast Asia. It has a hard, light, but very durable shell. It
was used for carrying liquids, ground paint (red ochre), and small items.
Domestication was important for two potentials to support human populations.
Plant Calorie Revolution – domesticated plants provided more calories per plant
and a greater number per unit of land than did wild ancestors. This is true of all the major
domesticated plants and especially the earliest - maize (corn) in Mesoamerica, potatoes
in the Andes, wheat and barley in the Middle East, and rice in Southeast Asia.
The domestication of maize in Mexico is an excellent example of the plant
domestication process for cultural reasons.
SLIDE 2: Map of Mexico: Area of first Maize domestication
SLIDE #3: Teosinte, the ancestor of maize. Note that it did not have cobs.
Those are a creation by humans by selecting for genes that increase productivity
SLIDE #4: Coxcatlan Cave in Puebla, Mexico. This is a dry thorn forest where
teosinte grows as a “weedy” grass in disturbed openings in the forest. Diminutive cobs
came from here some 4,000 years ago.
The first maize was not terribly productive and some wild plants like mesquite had a
greater yield. With further selection maize cobs increased in size and useful wild plants
became secondary as the land was cleared for maize.
SLIDE #5 Schema of Maize- Wild Plants in Mexico 6000-7000 years ago
SLIDE #6: By 3000 years ago Native Americas had selected for a great many varieties
of maize
SLIDE #7: Maize was carried to South America, the Caribbean, and the United Stares
from Mexico by exchange between bands.
SLIDE #8 and 9 Stages in Maize Evolution
SLIDE # 10 Corn Evolution
Animal/Plant Protein Revolution. For the most part plants provide calories and
animals provide protein. The first domesticated animal was the dog during the Upper
Paleolithic. Dogs came with the first humans across Beringia.
Domesticated animals led to the development of two food strategies: dead animal and
live animal.
Dead Animal Strategy. This is when animals are killed for their meat and hides. It is
practiced by hunters and gatherers and was the first results of hunting by human
ancestors.
Live Animal Strategy. This use of domesticated animals involves keeping the animal
alive but using by-products of the animal – wool, milk ( and new products like butter and
yogurt).
The Old World had many more domesticated animals than the new. There we find sheep,
goats, pigs, cattle, camels, horses, and water buffalo. The New World had the llama and
alpaca in South America but they never were brought across the tropics of Panama into
the northern latitudes.
Some plants also provide a vegetable protein and they were domesticated very soon after
the first grains. These include peas, chickpeas in the Near East, soybeans in China and
common beans in the Americas.
In the New World the first domesticated plant was the gourd squash (Cucurbita pepo). It
was domesticated for its hard shell as a container and its oily seeds for food.
SLIDE # 11
Landscape Changes
Domestication provided a dependable and predictable food supply unlike what hunters
and gatherers faced most of the time. Dependence upon domesticated plants led to land
clearance to increase the area dedicated to food production. If we examine an example
from the Lower Illinois Valley, USA, we find that people were living in mobile bands but
required ample territory in order to have a variety of plant species and alternative
locations for their growth.
SLIDE #13 Large Band Territories to Meet Food Needs
With domesticated plants and gardens the territories could be smaller and provide the
same or more calories.
SLIDE #14 Smaller Band Territories with Domesticated Plant and Garden but greater
disturbance to the landscape.
In all parts of the world the greater the number of domesticated plants and animals, the
larger the population and the more land that had to be cleared or new landscapes created.
First we find large field especially for staple grain or root crops. In arid areas, farm land
is created through the use of irrigation to bring water to the plants. In mountainous
regions, terracing the land makes new fields. This human technology increases the
productivity of the land.
For animals their needs are met with increased pasture. Animals could extend human
influence more efficiently by being used as draft animals or for transportation of goods or
people.
Human Population Explosion – Changing Social Institutions
OVERHEAD #8
The increase of human populations led to social problems that required resolution.
Bands could live in single dwellings or a few together. (A on your chart)
SLIDE #15 A Jomon hut in Japan occupied by a band family
With agriculture we have more people living in a community for protection and for
ceremonies necessary for a good harvest. (B on your chart)
SLIDE #16: Yayoi Village of Rice Agriculturalist in Japan. They were organized into
Tribes
In North America the most complex social organization were chiefdoms. They were
found in the Mississippi drainage after AD 900. Their villages were multiple with the
chief living in a large ceremonial center often with several earthen mounds. (C - D on
your chart)
SLIDE #17: Reconstruction of Powers Fort, a Mississippian mound site in Missouri.
Although like other Mississippian sites it only had domesticated dogs, it
did depend upon extensive field of corn with beans and squash also
grown.
State controlled large numbers of people, often of more than ethnic or linguistic group.
They have a monopoly of power and can support large public projects that will increade
the food supply. Cities are part of states The technological projects sponsored by states
can be quite massive. Irrigation works on the deserts on the Middle East, southwest
China, and Mexico are striking examples of what they accomplished.
SLIDE 18: A massive irrigation work in Mexico built by the Aztecs
They also terraced lands in South America, Southeast Asia, the Philippians, China, and
Japan. The largest were built under state authority to increase food supplies.
SLIDE 19: Inca Built Terracing in Peru
Pre-industrial cities were created by states and controlled by them. Here one could find
markets, public architecture, and municipal services. Cities, however, had enormous
environmental demands. They needed food for the large resident populations. They
required fuel for heat and cooking. This meant that forests were cut for firewood. They
had sanitation problems that could spread diseases. Many cities were population sinks,
places were epidemic diseases could reduce the population substantially. The polluted
water meant that the purest beverage was beer!
HANDOUT # 9 The Evolution of Social Complexity
When we examine bands through state organizations throughout the world, we find
similar social institutions in each everywhere. Bands are kin-based with ephemeral
leadership, egalitarian status for the residents, and an informal economy.
Tribes have more complex kinship groupings and more formal rituals but otherwise they
duplicate many of the band attributes.
Chiefdoms are very different. The leadership is hereditary and often revered.
States are very different. They are familiar to use because they had to deal with social
order and correct problems as we do. We find bureaucracies, systems of law, standing
armies (and the draft), and taxation. States and their market system demanded fancy
sumptuary goods to distinguish the elite from lower classes. This led to mining on a
large scale, the exploration for exotic minerals, smelting, and exceptional craft
production.
Empires and Colonization
Colonization of Exotic Foods
Population Crises
Ecological Imperialism
Pests and Plagues
Homogenization of the Global Environment
Empires
Empires are mega-states. They are formed through the military conquest of one state by
another. They cover large expanses of territory and control millions of people. We think
of the Roman Empire and the British Empire (where the sun never set). But after the
15th century the world was changed forever because of the ecological consequences
created by empires.
This was the era of colonization and the intercontinental movement of foods. People
migrated from one continent to another. Crops were introduced across the seas. Maize
was brought to Europe, Africa, and Asia. Wheat and barley came to the New World.
North America that had only the domesticated dog and turkey in the Southwest now had
cattle, sheep, goats, horses, pigs, and chickens. Cacao and spices were traded around the
world. One of the largest New World trade goods that have impacted the health of the
world ever after was tobacco.
The new foods in old economies led to previously marginal land devoted to agriculture.
In China sandy soil unsuited for rice now supported sweet potatoes and peanuts.
Mountainsides could grow corn and potatoes. In parts of China and Asia a marked
increase in population resulted with a more diversified economy lessening the threat of
starvation.
Ecological imperialism also resulted from the introduction of diseases and pests into
new areas. The people of the Western hemisphere had not been exposed to most of the
dieses of humankind before 1492. Within 100 years their numbers had been reduced
90%. Smallpox, influenza, diphtheria, the plague, malaria, and even the common cold
were unknown until Europeans brought them to a virgin population. In return Europeans
brought home syphilis as their gift from the New World.
Rats, mice, insects, and plant crop weeds all came to disrupt ecosystems in the
Americans, Africa, and Australia. The result was the homogenization of the earth’s
environment. Never again would the continent be pristine.
Human populations have grown enormously with the advent of agriculture. They have
grown with the importation of exotic foods after 1500. The social consequences resulting
from the spread of agriculture are profound and dramatic. Before agriculture, some
12000 years ago, the lifestyle of the earth’s inhabitants was 100% hunters and gathers.
Agriculture had spread to such a degree that by AD 1500 of the people then alive 1% was
hunters and gatherers. By 1985, within our lifetime, their numbers were reduced to
.0001% in remote parts of the Arctic, the Congo and pockets in the Australian desert. By
AD 2000 the world has a population of 6 billion but no hunters and gatherers.
We will now learn why and what this economic shift to full dependence on agriculture
means for the environment.
Suggested Readings:
Adams, Robert McC.
1966 THE EVOLUTION OF URBAN SOCIETY. Aldine
Boserup, Ester
1981 POPULATION AND TECHNOLOGICAL CHANGE. Chicago
Crosby, Alfred W.
1993 ECOLOGICAL IMPERIALISM: THE BIOLOGICAL
EXPANSION OF EUROPE, 900-1900. Cambridge
Diamond, Jerad
1995 “Easter’s End,” DISCOVERY: THE WORLD OF SCIENCE 16(5):
62-69
1997 GUNS,GERMS, AND STEEL: THE FATES OF HUMAN
SOCIETIES. W.W. Norton.
Pyne, Stephen J.
1998 “Forged in Fire: History, Land, and Anthropogenic Fire,”
ADVANCES IN HISTORIC ECOLOGY pp. 64-103
Smith, Bruce D.
1998 THE EMERGENCE OF AGRICULTURE. Scientific American
Library