unit 2: evolution lesson # 3 12.1: the fossil...
TRANSCRIPT
Unit 2: Evolution Lesson # 3
12.1: The Fossil Record
Answer the journal question in your notebook
Group Discussion
• Video Link
• Answer the questions in your lab notebook • What is a paleontologist?
• What do they study?
• What do we use this information for?
Objectives
• Describe the process of permineralization
• Explain the role of isotopes in dating fossils
Perminearlization Fossils
• Key concepts: Permineralization requires rapid burial in an area with water
• Over time, bones in the organism are replaced with minerals
• See page 361
Other Types of Fossils
Other Types of Fossils
What about this guy?
What about this guy?
Relative Dating
No, I don’t mean dating your cousin…
How is Age Determined?
Relative dating
• Estimates when an organism lived by comparing the location of fossils in layers of rock.
• Older organisms are in lower layers, younger organisms are in top layers.
Radiometric Dating
• Key Concept: Radiometric dating is a process that uses the half life of an isotope to calculate the age of a material.
Radiometric Dating
• Video • Graphing of the half life of class
Com
mon
Iso
tope
s U
sed • Carbon – 14: 5,730 years
• Uranium – 238: 4,468,000,000 years
• Potassium – 40: 1,300,000,000 years
• Uranium – 234: 80,000 years
Radiometric Dating
• How old is the Earth? • Which element should we use to date
the Earth?
Time for a Refresher
• How old is the Earth?
• Was early Earth hot or cold? Would you want to live then? Why or why not?
• How are permineralization fossils formed?
• What is a half life?
How to Date a Fossil Activity
• Get into groups of two
• Listen carefully to the instructions
Due Dates
• Geologic Timeline Due TODAY
• How to Date a Fossil Activity is due next class