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Can selection happen without people?

Can selection happen without people?

Lesson narration:
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Predict 1 of 2: What do you think might have happened to the green anoles, once the brown anoles arrived in Florida and started to get hungry?




Predict 2 of 2: Not all of the green anoles are exactly the same. Which green anoles do you think the brown anoles are most likely to catch?

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#Want to know more about how scientists study lizards?
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# Extensions
Below are ideas for extending this topic beyond the activity & exploration which you just completed.
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# Natural Selection Simulation

To show that selection can happen without people, play the Peppered Moth game. Here’s how:

  • Open the link. Click on and read “how to play” aloud. At the start of the game, half the moths are light-colored and half are dark.
  • Click “play game.” Choose to hunt for moths among trees with pale bark or trees with dark bark. Before choosing, ask students whether they think the color of the tree’s bark will make any difference to the moth population.
  • Make your choice. Suddenly, you’re a hungry bird, pecking at moths. In the upper left corner, you’ll see a timer and a count of how many moths you’ve eaten. Down below, you’ll see graphs that show how you have affected the moth population.
  • When the game ends, make a note of how the moth population changed. Then play again. This time choose the other type of forest. Once again, at the start, half the moths are light colored and half are dark. Note the results of the game.
  • Discuss as a class: How would you explain these results?
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species


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one specific kind of living thing that has similar characteristics and can produce offspring with one another
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predator


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an animal that hunts and eats other animals
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survive


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to stay alive
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trait


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something you can observe about a living thing, such as the number of toe scales of a lizard
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inherited trait


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a trait of a living thing that comes from its parents
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natural selection


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a process where certain traits help a living thing survive, so those traits are more likely to be passed to the next generation of offspring
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variation


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the different versions of a trait, such as the number of toe scales of a lizard
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adaptation


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a trait that helps a living thing survive in its environment
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population


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how many there are of a particular type of living thing
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generation


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all the living things born and living at around the same time
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graph


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an image that helps you understand information
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Image & Video Credits

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Exploration
Anole on rocks by JamieS93 , used under CC BY-SA
2 Anoles by numbers by Seadevil
tropical island by Christopher Michel , used under CC BY
brown geko by Michel Pierfitte , used under CC BY-SA
catching Anoles by Adam Algar
green geko by Tambako the Jaguar , used under CC BY-ND
white geko by Nick Hobgood , used under CC BY
Tokay climbing wall by Tokay Gecko
holding small Anole by txbowen , used under CC BY
green lizard with long tail by Melissa Gutierrez , used under CC BY-SA
Anole on log by Paul Hirst , used under CC BY-SA
lizard holding branch by L Church , used under CC BY
Cuban Anole by Thomas Brown , used under CC BY
cargo boat by Gerolf Drebes , used under CC BY-SA
large green lizard by Euku , used under CC BY-SA
fishermen by Anole Annals Blog
lizard on flowers by www.GlynLowe.com , used under CC BY-ND
Anole on pipe by Daniel Ramirez , used under CC BY
Lesson narration:

Activity Prep

Print Prep

In this lesson, students learn about an example of how nature, not human beings, can slowly change the appearance of an animal using the process of selection. In the activity, Lizard Island, students simulate how natural selection affects a group of tree-climbing green lizards when their island is invaded by hungry brown lizards. This simulation only works for groups of 16 or more students. If you have a smaller group, use the Small Group Version of this activity found in Prep Instructions.

Preview activity

Exploration

10 mins

Wrap-Up

5 mins

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