Evolution of Animals

 

STUDENTS WILL BE ABLE TO:
- Discuss role of evolution in development of adaptations.
- Explain the concept of natural selection.
- Identify that organisms change over time as a result of evolution.

GUIDING QUESTIONS:
How did organisms get their adaptations?
What happens to organisms when conditions change?

MATERIALS:
- Selected reading on evolution
- Cards listing major events in the history of the Earth

CLASS ACTIVITIES:
Day 1: Wonder
1. Open class by reading and discussing a short literary passage describing an adaptation in response to a changing environment. Suggested topics/books to select from include:

• The Song of the Dodo: Island biogeography in an age of extinctions - by David Quammen or other readings on island biogeography
• The Beak of the Finch: A story of evolution in our time - Jonathan Weiner
• Climbing Mount Improbable - Richard Dawkins
• Writing on near-extinction of cheetahs
• Discussion of salmon in the Pacific Northwest (Suggested: a comparison of the response of salmon to recent damming of rivers versus the effect of the gradual damming of rivers in the most recent Ice Age.)
• Reading on urban ecology - consider what animals live in the city and why
• Case study of moths in Great Britain in response to pollution from the Industrial Revolution

2. Discuss the reading, focusing on how the changing environment affected the organisms in both the short and long term.
3. Review or introduce the term evolution.
4. Hand out a stack of cards naming major events in the Earth's history. The list should include events such as the most recent ice age, development of an oxygen-rich atmosphere, the formation of Pangea, and the Industrial Revolution. It should not yet include events directly involving animals (for example, the extinction of the dinosaurs).
5. Working as a class, students should try to stand in chronological order.
6. If necessary, correct the timeline, putting students into the proper order. Post the timeline in a prominent place in the classroom.
7. Place on the timeline a few major events in the evolution of life. Ask students what would happen to living things during all of the subsequent events. Add mass extinction events to the timeline.
8. Assign groups of students extinction events to research. Selected events can be worldwide historical events, such as the Permian extinction, or can be more localized events, such as the eruption of Mt. Saint Helens or a local fire or storm.

Day 2: Explore
1. Groups should begin research. Students should focus on these questions:

• What was lost?
• What survived?
• Are there any patterns of what survived? For instance, were smaller or larger animals more likely to survive? Generalists or specialists?

Day 3: Identify
1. Students should complete research and develop a presentation (roughly 3 minutes long) of their findings.

Day 4: Round Table
1. In groups, students can present their findings.
2. Identify any trends observed.
3. Brainstorm current or potential changes to your local ecosystem. (Depending on your area, students may name changes such as habitat loss, temperature change, rising sea level, etc.) How might current animals respond to these changes?
4. Discuss: Do humans change or do they change their habitat?
5. Use remaining time to go over the lesson plan students will teach the following day.

Optional Extension:
1. Students should pick a particular animal adaptation and write a fable giving a fictional account of how that adaptation developed.