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EEB 304 Lecture 4 – Origins of Agriculture PowerPoint Presentation
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EEB 304 Lecture 4 – Origins of Agriculture

EEB 304 Lecture 4 – Origins of Agriculture

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EEB 304 Lecture 4 – Origins of Agriculture

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

  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

  3. 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

  4. Quiz • Where and when did agriculture begin? • Which continents are considered to make up the New World?

  5. Important Concepts • Timing – When did farming begin?

  6. Important Concepts • Timing – When did farming begin? • - sudden origin • - gradual conversion

  7. Important Concepts • Timing – When did farming begin? • - sudden origin • - gradual conversion • Evidence for adoption of agriculture • - dating • - plants

  8. Important Concepts • Timing – When did farming begin? • - sudden origin • - gradual conversion • Evidence for adoption of agriculture • - dating • - plants • Changes involved in plant domestication

  9. 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

  10. Important Terms Related to Origin of Agriculture Cultivation Domestication Agriculture Horticulture

  11. 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

  12. 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

  13. How long have people been on our planet? • modern humans - ca. 100,000 years ago

  14. How long have people been farming? • ca. 10,000 years • before farming - hunter gatherer type of existence

  15. Origin of Agriculture – Sources of Evidence • Physical evidence: Human encampments or settlements • Temporal evidence

  16. Origin of Agriculture – Sources of Evidence • Physical evidence: Human encampments or settlements • - plant remains • Temporal evidence

  17. Origin of Agriculture – Sources of Evidence • Physical evidence: Human encampments or settlements • - plant remains • - cooking utensils • - tools • - human skeletons • Temporal evidence

  18. Origin of Agriculture – Sources of Evidence • Physical evidence: Human encampments or settlements • - plant remains • - cooking utensils • - tools • - human skeletons • Temporal evidence • - stratigraphy

  19. Origin of Agriculture – Sources of Evidence • Physical evidence: Human encampments or settlements • - plant remains • - cooking utensils • - tools • - human skeletons • Temporal evidence • - stratigraphy • - isotope dating

  20. Origin of Agriculture – Sources of Evidence • Physical evidence: Human encampments or settlements • - plant remains • - cooking utensils • - tools • - human skeletons • Temporal evidence • - stratigraphy • - isotope dating • - tree rings

  21. Carbon-14 Dating Isotopes of Carbon: C12 - 98.89%

  22. Carbon-14 Dating Isotopes of Carbon: C12 - 98.89% C13 - 1.11% C14: 0.00000000010%

  23. 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]

  24. 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

  25. 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

  26. 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

  27. 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

  28. 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

  29. 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 • People utilize animals for food – animal bones go into the garbage dump after the flesh is eaten

  30. Carbon-14 Dating, continued 4. The animal bones lie in the corner of the cave where they are preserved

  31. 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.

  32. 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

  33. Carbon-14 Dating, Errors • Contamination: • residues from microorganisms • infiltration with carbon-containing water (e.g. carbonates) or organic-containing leachates

  34. 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

  35. 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

  36. 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.

  37. Tree Ring Analysis, continued Development of master sequence – can then be used to date individual artefacts

  38. Tree Ring Analysis, continued An example of a comprehensive data set for a given region (Aegean).

  39. Identification of Plant Remains See Fig. 2.1, p. 41 • Macroscopic appearance

  40. Identification of Plant Remains See Fig. 2.1, p. 41 • Macroscopic appearance • Pollen grains (instant fossils) Sunflower pollen

  41. Identification of Plant Remains See Fig. 2.1, p. 41 • Macroscopic appearance • Pollen grains (instant fossils) • Phytoliths (also very resistant to degradation) Sunflower pollen 2 phytoliths – SEM micrographs

  42. Identification of Plant Remains See Fig. 2.1, p. 41 • Macroscopic appearance • Pollen grains (instant fossils) • Phytoliths (also very resistant to degradation) • Indirect – wear data on human teeth; changes in Carbon isotope ratios (C-12/C-13) in human bones Sunflower pollen 2 phytoliths – SEM micrographs

  43. 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

  44. Apples – the Fruit of the Garden of Eden? See Fig. 2.8, p. 46 Traditional Depictions Show the Apple as the “Forbidden Fruit”

  45. 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

  46. 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

  47. 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

  48. 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 Contrast: Gift or Burden

  49. 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 Contrast: Gift or Burden Bottom Line: other explanations have been sought

  50. What caused the origin of agriculture? • climate change?