ORIGINS OF AGRICULTURE
David S. Seigler
Department of Plant Biology
University of Illinois
Urbana, Illinois 61801 USA
seigler@life.illinois.edu
http://www.life.illinois.edu/seigler
Origin of agriculture
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hunter-gatherer societies
past - resources available
sedentary vs. nomadic
cooking and other detoxification methods
knowledge needed to begin agriculture
theories for how agriculture began
the origins of specific crops
READING
CHAPTER 1: Read over chapter one: Plants and Their
Manipulation by People. We will refer to material from this
chapter throughout the semester.
CHAPTER 2: Origins of Agriculture.
Introduction
Important points to consider:
• We are absolutely dependent on plants.
• Ultimately, only plants can "harvest" the sun's
energy by photosynthesis.
• All nutrients and energy are cycled.
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Although we tend to think that we are less
dependent on plants today, this is partly a
U.S. and European bias. This is not true for
most people in the world. We are dependent
on fewer species of plants than formerly, but
even in the U.S. we are highly dependent on
plants.
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Petroleum is the remains of former plants.
What will we do when we use it up?
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In this course, we will talk about
domesticated plants, gathered plants, and
wild plants.
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Perhaps 10,000 plants (of possibly
350,000) are used by the peoples of the
earth, but all human civilization depends
mostly on 10 or fewer.
Processing of foods
• Cooking makes foods more edible
• There is an association of cooking and
detoxification of plants.
• Cooking made more plants usable by humans.
• Cooking arose before agriculture.
• Humans were using fire as much as one
million years ago
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The cultivation of plants began about
17,000 years ago.
Evidence for domestication of plants goes
back to about 12,000 years ago.
Text: page 41 ff. on dating methods.
There were, perhaps, 10,000,000 people on
earth at that time. By 2000 years ago, most of
the major peoples and regions of the earth
practiced agriculture.
By 1900, there were 1.6 X109 people.
Today there are about 6 X 109.
Before agriculture, humans were huntergatherers.
• By 1900, hunter-gatherer societies were
restricted to small areas that were too dry, too
cold or too wet for agriculture.
• In good areas, people of hunter-gatherer
societies don't have to learn to plant.
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Many hunter-gatherer societies know all
they need to know about growing plants, but
don't.
Some gatherers do plant seeds. Some
gatherers replant parts of root crops.
Most cultures are based on seeds, not
root crops, although many root crops are
important in the lowland tropics.
Some gatherers also irrigate.
Gatherers learned how to cook or
otherwise detoxify food plants.
• Our system requires energy input,
whereas gathering produces excess
energy.
Ethnobotanical humor
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There was an association of agriculture and
sedentary society.
• Cultivation may have arisen in the zones
between sedentary and hunter-gatherer
societies.
• Agriculture never arose in California and in
the sub Saharan African savanna.
• On the other hand, some sedentary people
never developed agriculture (e.g., fishermen).
• Studies of present day hunter-gatherers indicate
that they have considerable leisure time.
• Until recently, the !Kung bushmen of the Kalahari
desert were gatherers. They mostly ate 14 plants.
They recognized 105 species of edible plants. Their
diet was quite good in protein and in total calories.
They worked about 2.5 days per week to gather
food.
• Agricultural societies work harder.
• Most hunter-gatherers eat (ate) plants.
How do we know that? 12C/13C ratios,
dentition, abrasion on teeth.
Archaeology.
• Meat was an occasional luxury.
• Populations of hunter-gatherer peoples
usually are maintained below the
carrying capacity.
Origin(s) of agriculture?
• Why did agriculture arise?
• Where did agriculture begin? Almost all of the
oldest records are from the Near East.
• How do we know the plants they used were
cultivated?
Domesticated animals
• Domesticated animals (dog, sheep, goat,
cow) all arose about the same time as
domestication of plants. Only about 50
animals were ever domesticated.
• Animals may have been linked to religion.
• Animals were used to till fields mostly in the
Old World.
• Did agriculture arise as an extension of
gathering?
Theories of origin of plant domestication
1. religious: Many peoples viewed
agriculture as a gift from the gods.
Some have felt that agriculture arose for
religious reasons, i.e., for sacrifices
(more probable for animals).
2. "genius" or "eureka" theory (see "The
Source" Mitchener).
More theories ….
3. refuse heaps - Edgar Anderson.
This
might have been especially true around
houses or cattle pens. Both are also
disturbed areas. Parts of the plants that were
utilized were often discarded.
4. Carl O. Sauer felt man had to be sedentary
first. He favored SE Asia as the place of
origin. But many nomadic peoples grow
plants for food. The Near East center clearly
did not develop in the tropics.
Even more theories ….
5. Edgar Anderson saw weeds as
potential domesticates. They "preferred"
disturbed habitats.
Origins of particular crops
Alphonse De Candolle - in 1882, wrote a book on the
origin of cultivated plants. He based his ideas on
historical writings, archaeological information,
ethnological data, linguistics etc.
(1806-1893)
N. I. Vavilov
• N. I. Vavilov - added genetics, chromosome
studies, and anatomical data. He was
interested in the presence of wild ancestors.
• Vavilov concluded that the most likely areas
of origin were where the plant was cultivated
and the wild ancestors grew.
• Further, the areas of origin should be areas in
which there was lots of variation. He decided
that there were 8 major areas that met these
requirements.
Vavilov’s Centers
• These were: Mexico and Central America, the
Central Andes, Abyssinia, the Mediterranean,
Indian (Middle East), SW Asia, China, and SE
Asia.
• Later, he added more till he got up to about 20
or so. At this point you couldn't really call all of
them "centers".
Nicholai Vavilov
(1887 – 1943)
Vavilov’s Centers
Jack Harlan
Harlan concluded that there were three "centers": the
Near East, Northern China, and Meso-America and
three other areas with diffuse origins (S.E. Asia, S.
America, and much of Africa) that he called "noncenters".
Further, it had become clear that a "center of origin"
often was not the same as a "center of diversity".
Harlan concluded that it is very difficult to separate the
origin and later expansion of a successful crop.
Jack Harlan
(1917–1998)
J. R. Harlan, Plant Scientists. Franklin Watts. New York. 1964.
Harlan’s Centers and Non-centers
Every model generated so far has evidence for and against
it.
Some were for ritual, magic, ceremony, or religious
sacrifice. Some were from "dumps". Some weeds gave rise
to crops. Some crops gave rise to weeds. Some weed-crop
complexes had common progenitors. Some crops arose in
Vavilov's centers, some did not.
Some people were sedentary before agriculture. Harlan
proposed a "no-model" model. That is, he left room for a
whole array of motives, actions, practices, and evolutionary
processes.
Early agriculture
Many people with hunter-gatherer life styles used fire to
control or manage both plants and animals in their area.
This became common at the end of the Pleistocene
Epoch about 11,700 years ago.
Much agriculture by so-called primitive peoples today is of
the slash-and-burn type.
Prairies and savannahs are difficult to farm. Much
agriculture is on the margin of forested lands.
The advent of the steel plow made possible settlement of
the prairies and plains in the U.S. and Canada in the
middle 1800's.
Burning forest in Madagascar
Courtesy Dr. Voara Randrianasolo
Fields in Madagascar
Courtesy Dr. Voara Randrianasolo
Preparing the field
Planting the crops
Slash and burn agriculture in Venezuela
Egyptian agriculture
B. Lehane, Power of Plants, McGraw Hill. New York. 1977
Plowing in Bengla Desh
Courtesy Dr. Ted Hymowitz