Learning Guide: Speciation and Extinction
Bill Activity #12
To Think About: How does evolution by natural selection explain both the diversity of life and the adaptations
of organisms? What patterns of species and extinction have occurred in Earth’s past?
1st Read About: Hybrid zones and patterns of speciation and extinction
Pgs. 498- 504, pgs. 519-531 Campbell’s Biology 9th edition (Title your notes in your BILL
notebook. Also please use “2-sided column notes” or Cornell style format with the key points
on the left and the notes on the right, feel free to leave space at the bottom of each page to
write a summary, also add color and highlighting for the important ideas and key
points. These are your notes you will be using for in class discussions and studying
from.)
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Hybrid zones
 Hybrid zones provide opportunities to study factors that cause reproductive isolation. Describe
what a hybrid zone is and the causes for the unique pattern of allele frequencies in these zones.
 Sketch and describe the formation of a hybrid zone and the three possible outcomes for hybrids
over time.
 Explain the outcomes of hybrid zones by discussion three real world examples: European
flycatchers, cichlid fishes and Bombina.
Speciation rates
 Stephen Jay Gould and Niles Eldridge coined the term punctuated equilibria. What is meant by a
punctuated pattern? Contrast it with gradualism.
 Explain why rates of speciation can vary. Include several examples. What can we learn from this
data?
The rise and fall of groups of organisms in Earth’s past
 Changes in the fates of groups of organisms have been influenced by three major large-scale
processes. Explain each process in terms of their effects on speciation and extinction of life.
Include examples.
Evo-Devo
 Explain the two areas of biology that are merged in this field of study commonly called evodevo.
 Describe how heterochrony can cause the evolution of different body forms.
 Explain why it is likely that Hox genes have played a major role in the evolution of
morphological forms.
2nd Interact… Watch Mr. Andersen’s Speciation and Extinction video
 Draw arrows on the attached concept map and answer the video questions. Feel free to add additional
notes on the video guide as needed.
Supplementary Resources: Click the links below for more information to help you learn more about this
lesson.
 Crash Course: “Speciation”
 Kimball’s Biology Pages: Speciation
 UC Berkeley’s Understanding Evolution: Speciation
 UC Berkeley’s Understanding Evolution: Evo-Devo
 Nature article: “Darwin’s Finches Tracked to Reveal Evolution in Action.”
 University of Utah Learn.Genetics: Stickleback Evolution
 University of Utah Learn.Genetics: Foundational Toolkit Genes (Building an Eye)
 DNA From the Beginning: Master Genes Control Basic Body Plans
 University of Miami: Reproductive Isolation
Learn More: For more examples of speciation, use the links below:
 BBC’s GCSE Bitesize Biology:Natural Selection and Speciation
 TalkOrigins.org: Examples of Speciation
 Brown University: Case Histories of Speciation
 UC Berkeley: Evidence for Speciation