Name(s) ____________________________________________ Date ____________ Period ___
Understanding Evolution: Homology and Analogy
http://evolution.berkeley.edu/evolibrary/article/similarity_
hs_01
1. Read the first slide: Introduction to Similarities and
Differences
1. In the image, which pair represents an analogy and
which a homology? Label them.
2. Define homology:
3. Define analogy:
click “next”
Slide 2: The Tale of the Limb. Select the limb in the group that doesn’t belong (is not
homologous). Keep doing this until no more choices are given. The click “next.
Slide 3: The Tetrapod Limb.
1. What is a tetrapod?
2. What are the six bones found in all tetrapod legs?
3. Identify these limbs (to what animal do they belong)?
Click “next”
Slide 4: Inheriting homologies
1. What did the common ancestor of all modern tetrapods look like (describe)?
Click “next”.
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Slide 5: Homologies are everywhere
1. Look at the pictures. What structures on the beaver and the elephant are homologous?
Click “next”.
Slide 6: Not all similarities is homology
1. Similar structures that evolved independently are called _________________________.
Click “next”.
Slide 7: Analogies
1. What is the difference between a marsupial and a placental? (hint: click on the highlighted
links to find out)
2. What is Smilodon?
3. What is Thylacosmilus?
4. Look at the phylogenic tree diagram. Name a modern-day marsupial that is related to the
Thylacosmilus.
Click “next”.
Slide 8: How do analogies evolve?
Click the button to play the animation.
1. Describe how two unrelated flowers could evolve to have a similar appearance?
Click “next”.
Slide 9: Homology or analogy?
1. Are similarities between sharks and dolphins homologous or analogous? (Also, submit your
answer)
Click “next”.
Slide 10: Studying homologies and analogies
1. What is morphology? (hint: click the highlighted link)
2. What three criteria are used to determine whether something is a homology (not an analogy)?
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Click “next”.
Slide 11: Using homologies to reconstruct relationships
1. Fill in the blanks of the primate tree.
Click “next”.
Slide 12: Test your understanding
1. Considering all of the evidence, are the "wings" (actually flaps of skin stretched between the
legs) of sugar gliders and flying squirrels homologous or analogous structures? Give at least two
reasons why you would conclude this (also submit your answer on the website).
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