Origin of Species: Beak of the Finch
Revised November 2018
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Natural Selection and the Evolution
of Darwin’s Finches
There are 13 different species of finch on the Galápagos Islands off the coast of Ecuador. On one of the islands,
Daphne Major, biologists Peter and Rosemary Grant have devoted many years to studying four of these bird
species. The Grants have studied the effects of drought and periods of plenty on the finches, and the results of
their experiments have had an enormous impact on evolutionary science.
For this lesson, you will first analyze the characteristics of the 13 species of finch found on the Galápagos Islands.
Then you will watch a short film, The Origin of Species: The Beak of the Finch
, about the research conducted by
the Grants. Based on the information presented in the film and your own observations, you will construct an
argument and make predictions about the role of natural selection on the evolution of finch populations.
• Finch cards (13 cards per student team)
• Large, white poster board or butcher paper
• Blue painter’s tape for attaching cards to poster board or butcher paper
• Access to a camera (optional)
• Sticky notes or index cards
• Graph paper
• Science notebooks or paper for writing
• Different-colored pens (optional)
Break into teams as instructed by your teacher. Each team will receive 13 cards of different finch species. Follow
the instructions below, recording observations and answers to questions as directed by your teacher.
PART 1: What Do You Already Know?
1. Working with others on your team, examine the cards of the Galápagos finches and arrange the species into
groups based on their characteristics. Grouping species according to shared characteristics can provide clues
to how they have evolved.
2. On a large piece of poster board or butcher paper, use the tape to attach the cards according to the groups
your team has created (or you can display the groups on your table). Give each group an informative name
and write that name down next to each group. On sticky notes or index cards, list the evidence for each
3. Pause for a gallery walk. Walk around the class and examine the displays by the other teams, paying
attention to the following:
• How were other teams’ groupings similar to your team’s? How were they different?
• What evidence did your classmates use to justify their groupings?
• How does the evidence they provided support their groupings?
On your own, write two questions about each team’s presentation on sticky notes or index cards. Initial your