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Online Course for Teachers: Teaching Evolution

About this Course 

SESSION 3

SESSION 3: What Is the Evidence for Evolution?

Explain Part A: Fossil Evidence

Darwin used multiple lines of evidence to support his theory of evolution by natural selection -- fossil evidence, biogeographical evidence, and anatomical evidence.

I look at the geological record as a history of the world imperfectly kept, and written in a changing dialect; of this history we possess the last volume alone, relating only to two or three countries. Of this volume, only here and there a few lines. Each word of the slowly-changing language, more or less different in the successive chapters, may represent the forms of life, which are entombed in our consecutive formations, and which falsely appear to have been abruptly introduced.

(From Charles Darwin, On The Origin of Species. [New York: The Modern Library, 1993] p. 443)

Fossils are rare, and it is difficult to find ancestral fossil species that show a line of evolution from a common ancestor. Yet, scientists have amassed fossil data that explains much of the evolutionary history of life. Use the resources listed below to gather information on fossil evidence.

1. 

Watch these video segments from Evolution Shows Three and Two:

Image of a man hiking up steep mountainous terrain.  Image of humpback whales underwater.

Permian-Triassic Extinction
View in:
QuickTime | RealPlayer

Whale Evolution
View in:
QuickTime | RealPlayer

2. 

Read Chapters 9 and 10 of The Origin of Species at the Online Literature Library Web site to learn about Darwin's interpretation of the fossil evidence available in his time.

3. 

Review the fossil record section of Evidence Supporting Biological Evolution on the National Academy of Sciences Web site.

4. 

View examples from the fossil record at the Geology Wing of the University of California Museum of Paleontology Web site.

5. 

To learn about transitional fossil evidence, look at these pages on the Talk.Origins Web site:

• 

All About Archaeopteryx

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Transitional Vertebrate Fossils. Why do gaps exist? (or seem to exist)

6. 

Now, answer these questions.

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What are some key examples that illustrate how fossil evidence supports the theory of evolution?

• 

Describe why fossils are rare and why it is difficult to find ancestral fossil species that show a line of evolution from a common ancestor.

• 

What questions remain unanswered using just the fossil record?

 



 

Facilitator Note 2

 

Next: Explain Part B: Biogeographical Evidence

 
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