The History of Life

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The History of Life The Theory of Evolution

• Chapter 14

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Early Earth.

• What was it like?

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Who studies the Earths History?

• a. Geologists
• b. Anthropologists
• c. Archeologists

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Who studies the history of life?

• d. Paleontologists!

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Clues to the past.Evidence of Life

• FOSSILS (see figure 14.1)
• FOSSIL TYPES
• a. TRACE
• b. CAST
• c. PETRIFIED
• d. IMPRINTS
• e. AMBER-PRESERVED (frozen)
• f. MOLDS

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Fossil Types

• Trace

• Cast

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Fossil Types

• Petrified

• Imprint

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Fossil Types

• Amber-preserved

• Molds

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Fossil Formation Dating

• Relative Dating vs. Radiometric Dating
• Figure 14.3

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More about Relative vs. Absolute Dating

• What is the principle of superposition?

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Determining Age

• Carbon dating can be used for organisms less than
  ________ years old

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The changing Earth

• What is continental drift?
• Who came up with the idea?

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The sea floor is spreading

• What is
• sea floor
• spreading?

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Plate Tectonics

• It is a combination of 2 ideas
• Pangaea continental drift
• What is happening to the Pacific Ocean? The
  Atlantic Ocean?

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The Geological Time Scale

• It is a calendar of the Earths history
• ERA large span of time on the scale
• They are subdivided into PEROIDS
• Mass extinctions seem to have occurred between
  eras
• Divisions on the scale are distinguished by the
  organisms that lived at that time

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Further Divisions
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Other types of time scales
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Other types of time scales
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The 4 Eras of the Timescale

• Precambrian
• Paleozoic
• Mesozoic
• Cenozoic