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


- sudden origin

- gradual conversion

Important Concepts


- sudden origin


• Evidence for adoption of agriculture

- dating

- plants

Important Concepts


- sudden origin



- dating

- plants

• Changes involved in plant domestication

Important Concepts


- sudden origin



- 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



- plant remains




- plant remains

- cooking utensils

- tools

- human skeletons




- plant remains

- cooking utensils

- tools

- human skeletons


- stratigraphy



- plant remains

- cooking utensils

- tools

- human skeletons


- stratigraphy

- isotope dating



- plant remains

- cooking utensils

- tools

- human skeletons


- stratigraphy

- isotope dating

- tree rings

Carbon-14 DatingIsotopes of Carbon:

C12 - 98.89%


C12 - 98.89% C13 - 1.11% C14: 0.00000000010%


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%


Carbon-14 Dating

Atmosphere


Spontaneous decay: 14C => 14N + beta particle

Isotopes of Carbon:

C12 - 98.89% C13 - 1.11% C14: 0.00000000010%


Carbon-14 Dating

Atmosphere


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%


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


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




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




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


1. Macroscopic appearance

2. Pollen grains (instant fossils)

Sunflower pollen

See Fig. 2.1, p. 41




3. Phytoliths (also very resistant to degradation)

2 phytoliths – SEM micrographsSunflower pollen

See Fig. 2.1, p. 41




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


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


Problems:



Suggestion: Forbidden fruit was probably another plant, possibly the apricot (text) or the fig

See Fig. 2.8, p. 46


Problems:



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



- 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



- 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?


• climate change?

• accident of how people lived

(a) offshoot of fisherman culture more sedentary (b) dumpheap concept


• climate change?



• population pressure?


• climate change?




• interaction with religious rituals?


• climate change?




• 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




New View (Box 2.1, text) – gradual transition

- issue of origin less significant






Major Points:

1. Once adopted, agriculture stayed with culture






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 ...


• 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 ...


• 4-5+ Centers

• Sub-sahara Africa

• somewhat later date, again preservation is a problem

Corn, Common Bean, Cocoa, Chili Pepper, Sweet Potato


• 4-5+ Centers

• Mexico

• Tamaulipas, 7500-9000 years ago; clearly by 7000 years ago maize in cultivation


• 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


• 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

EEB 304 Lecture 4 – Origins of Agriculture Reading: Chapter 2.

Documents

Transcript of EEB 304 Lecture 4 – Origins of Agriculture Reading: Chapter 2.