Chapter 2- Origins of an Agricultural Way of Life
Humans turned from a nonagricultural to an agricultural way of life.
Agriculture
This caring for plants can be minimal or intensive, ranging from the nuturing of essentially wild plants to carefully sowing and
rearing selected species.
Farming
Horticulture
Domestication
In most cases, domestication follows closely behind sustained cultivation.
Artificial selection can lead to cultivated crops that are so distinctive in appearance that it can be difficult to trace them back to
wild species.
When did humans first become farmers rather than hunter-gatherers?
Another source of data is fossilized plant material in archeological digs
that differ significantly in quantity from local wild plants.
The plant and animal remains used for such analyses are found in:
Pollen grains are particularly useful for identifying plant remains.
Phytoliths and starch grains have been increasingly important
to identify fossilized plant remains as domesticated or wild.
Dating Plant Fossils
The Carbon-14 method uses the natural occurrence of radioactive carbon isotope that decays at a known rate.
Radioactive isotope
An isotope in which the nucleus of the atoms decays, and gives off particles and energy.
The Carbon-14 method uses the natural occurrence of radioactive carbon isotope that decays at a known rate.
Dating Plant Fossils
Accelerator Mass Spectrometry (AMS)
Molecules of carbon compounds are accelerated and smashed with detectors that analyze the ratio of C 12 to C14 atoms.
http://pages.vassar.edu/realarchaeology/files/2014/09/AMS-picture.jpg
What have analyses of fossilized plants revealed?
Was there a cradle of agriculture?
Because the earliest dates indicate that the large-scale practice of agriculture comes from archeological sites around the
eastern edge of the Mediterranean, this region has been labeled the cradle of agriculture, or the Fertile Crescent.
Was there a cradle of agriculture?
-Rice was cultivated about 10,000-11,000 years ago in the Yangtze River Valley of eastern China.
-Phyotliths from millet husks in northern China indicates domestication between 8,700 to 10,300 years ago, and
11,000 ybp in southern China.
-Seeds of domesticated squash found in Oaxaca, Mexico, was dated 10,000 ybp.
-Dates for the domestication of corn from phytoliths from grinding stones in Balsas Mexico are about 9,000 ybp.
From this evidence, it seems improbable that the practice of agriculture could have spread from a single source.
How did humans learn to cultivate plants?
Both oral history and written history are full of ideas about how people first learned about agriculture.
In the Old World, Mediterranean cultures have myths of goddesses as the keepers of agriculture.
How did humans learn to cultivate plants?
Greek myth of Demeter and her daughter Persephone
Osiris taught humans about growing grain and brewing beer.
Chinese legend also gives him credit for the knowledge of how to clear and burn forests.
How did humans learn to cultivate plants?
In Central America, the Aztec god, Quetzalcoatl appears in many myths
Almost all native people developed their own explanations of how
humans learned the purposeful cultivation of plants.
In contrast to the myths of other cultures, the Judeo-Christian account
in the book of Genesis states that “the Lord God sent them from the
Garden of Eden to till the ground from whence they had taken.”
In more recent times, authors have tried to explain the origin of agriculture with other ideas.
Dump Heap Hypothesis (Edgar Anderson)
-Because the wild relatives of many cultivated plants occur in open and often disturbed habitats, then the seeds could
have germinated and produced a “vegetable garden.”
Carl O. Sauer
-Sauer hypothesized that people living in settlements in areas with abundant wild food, water and a diversity of plants
useful for domestication.
-In these villages, people had enough leisure time to think about making improvement.
How did humans learn to cultivate plants?
A considerable body of evidence now indicates that modern nonagricultural people had the knowledge to grow crops,
but chose not to until something “pushes them over the edge.”
Why did populations in different parts of the world shift
independently and completely to an agricultural way of life?
Modern studies suggest that primitive agriculture was a more
difficult way to make a living than traditional hunting and gathering
in a nonstressed ecosystem.
People turned to agriculture only when forced to do so.
Several theories have been proposed to explain why a change to
farming might have become necessary or why the balance shifted:
Climatic change has been a primary factor indicated for “forcing” a shift to farming
-The climate around the eastern Mediterranean became drier after the last major Pleistocene glaciation (12,000-10,000 ybp)
Abandonment of hunting and gathering
-Human populations outgrew wild plant resources available on a year-round basis.
-They gathered and stored wild plants like mature grains in large amounts.
Origins of Particular Crops
Although there is still some debate about why and how agriculture was adopted as a way of life, there is better evidence
for the possible times and sites of domestication of many specific crops.
Alphonse de Candolle was the first person to seriously study crop plants and their origins.
In 1882, he published a book titled Origins of Cultivated Plants which compiled information from the following sources:
The most comprehensive treatments of crop plant origins came from Nikolay Vavilov who tried to find the centers of origin
(“gene centers”) of cultivated species.
Vavilov made two assumptions:
Origins of Particular Crops
Vavilov distinguished 6, soon expanded to 8, major centers of domestication.
1-China (Chinese center)
2/2a-India/Indochina (Indian center)
3-Central Asia (N. India, Afghanistan, Turkmenistan) (Central Asian center)
4-The Near East (Middle East center)
5-Mediterranean Sea, coastal and adjacent regions (Mediterranean center)
6-Ethiopia (Abyssinian center)
7-Southern Mexico and Middle America (Mexico-Central American center)
8/8a-Northeastern South America, Bolivia, Ecudor, Peru/Isle of Chile (central Andean center)
Study outline-Chapter 2- Origins of an Agricultural Way of Life
-Understand the following definitions: agriculture; farming; horticulture; domestication; artificial selection
-When did humans first become farmers rather than hunter gatherers?
-What are the ways of finding and dating evidence?
-What are sources of fossilized plant material?
-material from garbage dumps; ancient hearths; pot fragments
-pollen grains
-phytoliths (Fig. 2.1)
-starch grains
-How are plant fossils dated?
-carbon-14/radiometric dating
-acceleration mass spectrometry (AMS)
-What have analyses of fossilized plants revealed?
-Where is the Fertile Crescent? (Fig. 2.3)
-Was there an actual “cradle of agriculture?”
-How did humans learn to cultivate plants from oral history and written history?
-Examples from Greek, Egyptian, Chinese and Central American mythology; Judeo-Christian biblical story
(Figures 2.5-2.9)
-Understand more recent scientific hypotheses about how humans learned to cultivate plants.
-Dump Heap Hypothesis (Edgar Anderson)
-Hypotheses of Carl Sauer
-Why did populations in different parts of the world shift independently and completely to an agricultural way of life?
-Understand theories that have been proposed to explain the shift to farming.
-Understand ideas about the origin of food crops.
-Alphonse de Candolle – Origins of Cultivated Plants
-Nikolay Vavilov- “gene centers”
-What were Vavilov’s main assumptions?
-What are Vavilov’s 8 major centers of domestication?
-What are some major plant examples from each center? (Table 2.1)