EEB 304 Lecture 4 – Origins of Agriculture Reading: Chapter 2.
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Transcript of EEB 304 Lecture 4 – Origins of Agriculture Reading: Chapter 2.
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 #3List 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. BackgroundI. 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. BackgroundI. 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
Cooking?
How long have people been on our planet?How long have people been on our planet?
• modern humans - ca. 100,000 years ago
How long have people been farming?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 DatingIsotopes of Carbon:
C12 - 98.89%
Carbon-14 DatingIsotopes of Carbon:
C12 - 98.89% C13 - 1.11% C14: 0.00000000010%
Carbon-14 DatingIsotopes 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
Atmosphere
Cosmic ray neutrons 14N + neutron => 14C + proton
Isotopes of Carbon:
C12 - 98.89% C13 - 1.11% C14: 0.00000000010%
1 C14 atom for every 1,000,000,000,000 C12 atoms
Carbon-14 Dating
Atmosphere
Cosmic ray neutrons 14N + neutron => 14C + proton
Spontaneous decay: 14C => 14N + beta particle
Isotopes of Carbon:
C12 - 98.89% C13 - 1.11% C14: 0.00000000010%
1 C14 atom for every 1,000,000,000,000 C12 atoms
Carbon-14 Dating
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
Isotopes of Carbon:
C12 - 98.89% C13 - 1.11% C14: 0.00000000010%
1 C14 atom for every 1,000,000,000,000 C12 atoms
Carbon-14 Dating, continued1. 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, continued1. 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, continued1. 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, continuedLaboratory 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, ErrorsContamination:
- residues from microorganisms
- infiltration with carbon-containing water (e.g. carbonates) or organic-containing leachates
Carbon-14 Dating, ErrorsContamination:
- 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, ErrorsContamination:
- 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, continuedAn 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
1. Macroscopic appearance
2. Pollen grains (instant fossils)
3. Phytoliths (also very resistant to degradation)
2 phytoliths – SEM micrographsSunflower pollen
See Fig. 2.1, p. 41
Identification of Plant Remains
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
2 phytoliths – SEM micrographsSunflower pollen
See Fig. 2.1, p. 41
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?Traditional Depictions Show the Apple as the “Forbidden Fruit”
See Fig. 2.8, p. 46
Apples – the Fruit of the Garden of Eden?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
See Fig. 2.8, p. 46
Apples – the Fruit of the Garden of Eden?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
See Fig. 2.8, p. 46
Apples – the Fruit of the Garden of Eden?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
See Fig. 2.8, p. 46
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
- Mesoamerica
- Judeo-Christian
Contrast: Gift or Burden
Bottom Line: other explanations have been sought
See Figs. 2.4, 2.5, 2.6, 2.7, 2.8 pages 44,45,46
What caused the origin of agriculture?What caused the origin of agriculture?
• climate change?
What caused the origin of agriculture?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?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?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?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?
• single brilliant person?
• interaction with religious rituals?
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
Barley, Wheat, Lentils, Chickpeas, Olives ...
Where did agriculture originate?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
Rice, Millet, Soybeans ...
Where did agriculture originate?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
Sorghum, Millet, Okra, Coffee, Cotton ...
Where did agriculture originate?Where did agriculture originate?
• 4-5+ Centers
• Sub-sahara Africa
• somewhat later date, again preservation is a problem
Corn, Common Bean, Cocoa, Chili Pepper, Sweet Potato
Where did agriculture originate?Where did agriculture originate?
• 4-5+ Centers
• Mexico
• Tamaulipas, 7500-9000 years ago; clearly by 7000 years ago maize in cultivation
Where did agriculture originate?Where did agriculture originate?
• 4-5+ Centers
• South America:
• Peru, 8000 years ago
Potato, Tomato, Manioc, Peanut, Pineapple
Sunflower, sumpweed, chenopod in cultivation before arrival of corn and beans
Where did agriculture originate?Where did agriculture originate?
• 4-5+ Centers
• North America
Assignment #3List 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