Transcript Tuesday 1/23/01 – Origins of Agriculture

EEB 304 Lecture 4 – Origins of
Agriculture
Reading: Chapter 2
Tuesday February 1/subject to change!
Class will meet at McClung Museum
- meet in entry area, benches by fountain
- bring materials to take notes
Assignment #3
List 5 plant foods that you have consumed this week (they may
be foods that consist entirely of the plant; or foods that contain
the plant as one of the ingredients). Prepare a one page world
map that is labeled to show where each plant food originated
(use Table 2.1 of your textbook as your source of information)
Due Date: Tuesday 2/1
Can Be Returned as Hard Copy or File Attachment to
e-mail message
Quiz
1. Where and when did agriculture begin?
2. Which continents are considered to make
up the New World?
Important Concepts
• Timing – When did farming begin?
Important Concepts
• Timing – When did farming begin?
- sudden origin
- gradual conversion
Important Concepts
• Timing – When did farming begin?
- sudden origin
- gradual conversion
• Evidence for adoption of agriculture
- dating
- plants
Important Concepts
• Timing – When did farming begin?
- sudden origin
- gradual conversion
• Evidence for adoption of agriculture
- dating
- plants
• Changes involved in plant domestication
Important Concepts
• Timing – When did farming begin?
- sudden origin
- gradual conversion
• Evidence for adoption of agriculture
- dating
- plants
• Changes involved in plant domestication
• Where did farming begin
- independent invention vs. cultural diffusion
Important Terms Related to
Origin of Agriculture
Cultivation
Domestication
Agriculture
Horticulture
I. Background
How long have people been on our planet?
• Homo - ca 3 million years
• Fire - ca 1.4 million years
• Homo sapiens - In Africa ca 400,000 years ago
I. Background
How long have people been on our planet?
Cooking?
• Homo - ca 3 million years
• Fire - ca 1.4 million years
• Homo sapiens - In Africa ca 400,000 years ago
How long have people been on our planet?
• modern humans - ca.
100,000 years ago
How long have people been farming?
• ca. 10,000 years
• before farming - hunter gatherer type of existence
Origin of Agriculture – Sources
of Evidence
1. Physical evidence: Human encampments or settlements
2. Temporal evidence
Origin of Agriculture – Sources
of Evidence
1. Physical evidence: Human encampments or settlements
- plant remains
2. Temporal evidence
Origin of Agriculture – Sources
of Evidence
1. Physical evidence: Human encampments or settlements
- plant remains
- cooking utensils
- tools
- human skeletons
2. Temporal evidence
Origin of Agriculture – Sources
of Evidence
1. Physical evidence: Human encampments or settlements
- plant remains
- cooking utensils
- tools
- human skeletons
2. Temporal evidence
- stratigraphy
Origin of Agriculture – Sources
of Evidence
1. Physical evidence: Human encampments or settlements
- plant remains
- cooking utensils
- tools
- human skeletons
2. Temporal evidence
- stratigraphy
- isotope dating
Origin of Agriculture – Sources
of Evidence
1. Physical evidence: Human encampments or settlements
- plant remains
- cooking utensils
- tools
- human skeletons
2. Temporal evidence
- stratigraphy
- isotope dating
- tree rings
Carbon-14 Dating
Isotopes of Carbon:
C12 - 98.89%
Carbon-14 Dating
Isotopes of Carbon:
C12 - 98.89%
C13 - 1.11%
C14: 0.00000000010%
Carbon-14 Dating
Isotopes of Carbon:
C12 - 98.89%
C13 - 1.11%
C14: 0.00000000010%
1 C14 atom for every 1,000,000,000,000 C12 atoms
[=1 trillion]
Carbon-14 Dating
Isotopes of Carbon:
C12 - 98.89%
C13 - 1.11%
C14: 0.00000000010%
1 C14 atom for every 1,000,000,000,000 C12 atoms
Atmosphere
Cosmic ray neutrons 
14N + neutron => 14C + proton
Carbon-14 Dating
Isotopes of Carbon:
C12 - 98.89%
C13 - 1.11%
C14: 0.00000000010%
1 C14 atom for every 1,000,000,000,000 C12 atoms
Atmosphere
Cosmic ray neutrons 
14N + neutron => 14C + proton
Spontaneous decay:
14C => 14N + beta particle
Carbon-14 Dating
Isotopes of Carbon:
C12 - 98.89%
C13 - 1.11%
C14: 0.00000000010%
1 C14 atom for every 1,000,000,000,000 C12 atoms
Atmosphere
Cosmic ray neutrons 
14N + neutron => 14C + proton
Spontaneous decay:
14C => 14N + beta particle
Over time, this reaction has reached an equilibrium in the
atmosphere
Carbon-14 Dating, continued
1. Plants incorporate carbon from
the atmosphere as CO2 into their
tissues – at this point, the proportion
of C-12/C-14 will be the same as for
the atmosphere
Carbon-14 Dating, continued
1. Plants incorporate carbon from
the atmosphere as CO2 into their
tissues – at this point, the proportion
of C-12/C-14 will be the same as for
the atmosphere
2. Herbivores consume plants – the C-12/C-14
ratio will be maintained,and the lifetime of an
animal is too short for there to be any
detectable difference
Carbon-14 Dating, continued
1. Plants incorporate carbon from
the atmosphere as CO2 into their
tissues – at this point, the proportion
of C-12/C-14 will be the same as for
the atmosphere
2. Herbivores consume plants – the C-12/C-14
ratio will be maintained,and the lifetime of an
animal is too short for there to be any
detectable difference
3. People utilize animals for
food – animal bones go
into the garbage dump
after the flesh is eaten
Carbon-14 Dating, continued
4. The animal bones lie in the corner of
the cave where they are preserved
Carbon-14 Dating, continued
4. The animal bones lie in the corner of
the cave where they are preserved
Over time, the
proportion of C-14
to C-12 drops,
because C-14
spontaneously
decays whereas
C-12 is stable.
Carbon-14 Dating, continued
Laboratory studies have shown that the half-life of C-14 is 5568 years
– that is, in 5,568 years, half of the C-14 in a sample will be changed
into N-14 through radioactive decay. Using this information, a graph
can be prepared that shows the relationship between the proportion of
C-14/C-12 in a sample and its predicted age. Dating of samples whose
age is known has verified the technique (see graph below).
See Fig. 2.2,
p. 42
Carbon-14 Dating, Errors
Contamination:
- residues from microorganisms
- infiltration with carbon-containing water (e.g. carbonates) or
organic-containing leachates
Carbon-14 Dating, Errors
Contamination:
- residues from microorganisms
- infiltration with carbon-containing water (e.g. carbonates) or
organic-containing leachates
Special advantages/problems with wood:
- relatively abundant; likely to be present as charcoal
- wood may have been made much earlier than when it was used
Carbon-14 Dating, Errors
Contamination:
- residues from microorganisms
- infiltration with carbon-containing water (e.g. carbonates) or
organic-containing leachates
Special advantages/problems with wood:
- relatively abundant; likely to be present as charcoal
- wood may have been made much earlier than when it was used
Sampling errors:
- apply to all statistical techniques; lessen by replication
Tree Ring Analysis
Wood = secondary xylem
Temperate regions, often a ring of
secondary xylem is produced each
year - the ring is produced by
differences in size between cells
produced early in the season
(large) and those produced late in
the growing season (small).
The width of a tree ring provides
information about the growing
conditions of that season.
Tree Ring Analysis, continued
Development of master
sequence – can then be used
to date individual artefacts
Tree Ring Analysis, continued
An example of a comprehensive data set for a given region (Aegean).
Identification of Plant Remains
1. Macroscopic appearance
See Fig. 2.1,
p. 41
Identification of Plant Remains
1. Macroscopic appearance
2. Pollen grains (instant fossils)
Sunflower pollen
See Fig. 2.1,
p. 41
Identification of Plant Remains
See Fig. 2.1,
p. 41
1. Macroscopic appearance
2. Pollen grains (instant fossils)
3. Phytoliths (also very resistant to degradation)
Sunflower pollen
2 phytoliths – SEM micrographs
Identification of Plant Remains
See Fig. 2.1,
p. 41
1. Macroscopic appearance
2. Pollen grains (instant fossils)
3. Phytoliths (also very resistant to degradation)
4. Indirect – wear data on human teeth; changes in Carbon
isotope ratios (C-12/C-13) in human bones
Sunflower pollen
2 phytoliths – SEM micrographs
Origin of Agriculture: Cultural Myths
Many Cultures Have Stories About How People Learned to
Cultivate Plants
- Egypt
- Greece
- China
- Mesoamerica
- Judeo-Christian
See Figs. 2.4,
2.5, 2.6, 2.7, 2.8
pages 44,45,46
Apples – the Fruit of the Garden of Eden?
See Fig. 2.8, p. 46
Traditional Depictions Show the Apple as
the “Forbidden Fruit”
Apples – the Fruit of the Garden of Eden?
See Fig. 2.8, p. 46
Traditional Depictions Show the Apple as
the “Forbidden Fruit”
Problems:
- apples did not occur in relevant
geographic area, nor were they part of the
diet of the peoples there
- Hebrew word means both fruit and apple
Apples – the Fruit of the Garden of Eden?
See Fig. 2.8, p. 46
Traditional Depictions Show the Apple as
the “Forbidden Fruit”
Problems:
- apples did not occur in relevant
geographic area, nor were they part of the
diet of the peoples there
- Hebrew word means both fruit and apple
Suggestion: Forbidden fruit was
probably another plant, possibly the
apricot (text) or the fig
Apples – the Fruit of the Garden of Eden?
See Fig. 2.8, p. 46
Traditional Depictions Show the Apple as
the “Forbidden Fruit”
Problems:
- apples did not occur in relevant
geographic area, nor were they part of the
diet of the peoples there
- Hebrew word means both fruit and apple
Suggestion: Forbidden fruit was
probably another plant, possibly the
apricot (text) or the fig
Medieval Propaganda: Choice of Apple
denigrates traditional Celtic Religious
Beliefs
Origin of Agriculture: Cultural Myths
Many Cultures Have Stories About How People Learned to
Cultivate Plants
- Egypt
- Greece
- China
- Mesoamerica
- Judeo-Christian
Contrast: Gift or Burden
See Figs. 2.4,
2.5, 2.6, 2.7, 2.8
pages 44,45,46
Origin of Agriculture: Cultural Myths
Many Cultures Have Stories About How People Learned to
Cultivate Plants
- Egypt
- Greece
- China
See Figs. 2.4,
2.5, 2.6, 2.7, 2.8
pages 44,45,46
- Mesoamerica
- Judeo-Christian
Contrast: Gift or Burden
Bottom Line: other explanations have been sought
What caused the origin of agriculture?
• climate change?
What caused the origin of agriculture?
• climate change?
• accident of how people lived
(a) offshoot of fisherman culture  more sedentary
(b) dumpheap concept
What caused the origin of agriculture?
• climate change?
• accident of how people lived
(a) offshoot of fisherman culture  more sedentary
(b) dumpheap concept
• population pressure?
What caused the origin of agriculture?
• climate change?
• accident of how people lived
(a) offshoot of fisherman culture  more sedentary
(b) dumpheap concept
• population pressure?
• interaction with religious rituals?
What caused the origin of agriculture?
• climate change?
• accident of how people lived
(a) offshoot of fisherman culture  more sedentary
(b) dumpheap concept
• population pressure?
• interaction with religious rituals?
• single brilliant person?
Alternative Views – Origin of
Agriculture
“Classical View” – sudden, dramatic event; requires explanation
-
raises issue of single vs. multiple origins
Alternative Views – Origin of
Agriculture
“Classical View” – sudden, dramatic event; requires explanation
-
raises issue of single vs. multiple origins
New View (Box 2.1, text) – gradual transition
-
issue of origin less significant
Alternative Views – Origin of
Agriculture
“Classical View” – sudden, dramatic event; requires explanation
-
raises issue of single vs. multiple origins
New View (Box 2.1, text) – gradual transition
-
issue of origin less significant
Major Points:
1. Once adopted, agriculture stayed with culture
Alternative Views – Origin of
Agriculture
“Classical View” – sudden, dramatic event; requires explanation
-
raises issue of single vs. multiple origins
New View (Box 2.1, text) – gradual transition
-
issue of origin less significant
Major Points:
1. Once adopted, agriculture stayed with culture
2. Agriculture adopted in various parts of the world, with
differing sets of plants
Where did agriculture originate?
• 4-5+ Centers
• Near East
• area now
parts of Turkey,
Iran, Iraq:
probably oldest,
archaeological
materials
showing early
agriculture
known from ca.
10,000 years
ago
Barley, Wheat, Lentils, Chickpeas, Olives ...
Where did agriculture originate?
• 4-5+ Centers
• Southeast Asia
• Possibly 9,000
years ago, in
Thailand:
because of
warm, humid
climate, there is
poor
preservation of
materials
Rice, Millet, Soybeans ...
Where did agriculture originate?
• 4-5+ Centers
• Sub-sahara Africa
• somewhat
later date,
again
preservation is
a problem
Sorghum, Millet, Okra, Coffee, Cotton ...
Where did agriculture originate?
• 4-5+ Centers
• Mexico
• Tamaulipas,
7500-9000
years ago;
clearly by 7000
years ago
maize in
cultivation
Corn, Common Bean, Cocoa, Chili Pepper, Sweet Potato
Where did agriculture originate?
• 4-5+ Centers
• South America:
• Peru, 8000
years ago
Potato, Tomato, Manioc, Peanut, Pineapple
Where did agriculture originate?
• 4-5+ Centers
• North America
Sunflower, sumpweed, chenopod in cultivation before arrival of
corn and beans
Assignment #3
List 5 plant foods that you have consumed this week (they may
be foods that consist entirely of the plant; or foods that contain
the plant as one of the ingredients). Prepare a one page world
map that is labeled to show where each plant food originated
(use Table 2.1 of your textbook as your source of information)
Due Date: Tuesday 2/2
Can Be Returned as Hard Copy or File Attachment to
e-mail message
Thursday Lecture – Origin of
Agriculture, continued
- Geographical origin of plant crops
- Changes under domestication