|Karen F. Schmidt
Rolling Hills Middle School, CA
| Dr. Jonathan Hendricks
San Jose State University, CA
Driving Questions for Lessons
- Why do marine snails have so many different shapes and designs?
- In what ways do different snail shell designs “solve a problem”?
- How similar are ancient and modern marine snail designs?
8th Grade Integrated Science
6-7 hours (3 block periods or 6-7 short class periods)
NGSS Performance Expectations:
MS-LS4-2: Natural Selection and Adaptations
Apply scientific ideas to construct an explanation for the anatomical similarities and differences among modern organisms and between modern and fossil organisms to infer evolutionary relationships.
MS-LS2-2: Interdependent Relationships in Ecosystems
Construct an explanation that predicts patterns of interactions among organisms across multiple ecosystems. (Examples: competition and predation)
NGSS Disciplinary Core Ideas:
LS4.A: Evidence of Common Ancestry and Diversity
Anatomical similarities and differences between various organisms living today and between them and organisms in the fossil record, enable the reconstruction of evolutionary history and the inference of lines of evolutionary descent.
Adaptation by natural selection acting over generations is one important process by which species change over time in response to changes in environmental conditions. Traits that support successful survival and reproduction in the new environment become more common; those that do not become less common. Thus, the distribution of traits in a population changes.
Developing Possible Solutions
ETS1.B: There are systematic processes for evaluating solutions with respect to how well they meet the criteria and constraints and of a problem.
Relevant Science & Engineering Practices:
Planning and Carrying Out Investigations
Analyzing and Interpreting Data
Constructing Explanations and Designing Solutions
Engaging in Argument from Evidence
Relevant Crosscutting Concepts:
Structure and Function
Cause and Effect
Relevant COMMON CORE STANDARDS:
Reading, Writing and Speaking:
RST.6-8.1 Cite specific textual evidence to support analysis of science and technical texts.
WHST.6-8.2 Write informative/explanatory texts, including the narration of historical events, scientific procedures/experiments or technical processes.
SL.8.1 Engage effectively in a range of collaborative discussions (one-on-one, in groups, teacher-led) with diverse partners on grade level topics, texts, and issues, building on others’ ideas and expressing their own clearly.
6.SP.B.5 Summarize numerical data sets in relation to their context.
Resources & Materials
Graphs by Geerat Vermeij with explanations and writing prompts
See Shape of Life “Shell Shocked” Lab Activity (can be adapted for ELs)
Mollusc Fact Sheet:
“An Interpretation of Vermeij’s Data” (adapted from Shape of Life’s “Shell Shocked”)
Shape of Life: Mollusc Animation: Abalone Body Plan
Shape of Life: Mollusc Animation: Shell Repair
Shape of Life: Pycnopodia Chases Abalone
Shape of Life: Moon Snail Preys on Cockles
Shape of Life: The Survival Game
You Tube: Killer Cone Snails (National Geographic)
Video resources about The Story of the Animal Kingdom:
Blog about cone snails by Jonathan Hendricks:
Panamanian Fossil Record of the Killer Cone Shells
Atlas for information on fossil mollusk species:
Specimens: Sets of 8 different gastropod shells, such as fossils from Gatun that include cone snails, olives, whelks, turritellas, etc. One set of modern marine gastropod shells could also be looked at for comparison.
Student science notebooks
Guest speaker: Jonathan Hendricks, Professor of Paleontology and expert on cone snails, interview by Skype or Google Hangouts
Images of cone snail patterns under UV lamp
- Who/what lived in these fossil shells?
- What are molluscs?
- Why do molluscs have so many different shell designs?
- Why are some features—such as spirals—common?
- What eats a marine mollusc and how?
- How do molluscs defend themselves?
- How do molluscs grow their shells?
- What materials are seashells made of?
- Which kind of gastropod has the best design to defend itself against predators?
- What is coevolution and how is it “an arms race”?
- What evidence do scientists use to explain coevolution of molluscs and their predators?
Key Academic and/or Scientific Language
Mollusc, gastropod, bivalve, cephalopod, predator, prey, aperture, protrusion, shell wall, spire, siphonal canal, coevolution, arms race, trait, adaptation.
What knowledge and skills will students acquire?
Students will be able to:
- Observe, compare, describe, and evaluate snail shell design features
- Explain how specific shell structures have a defensive function
- Explain predator-prey relationships
- Analyze and interpret graphs of data related to the evolutionary arms race between marine snails and shell-breakers
- Read a nonfiction article for information about how and why molluscs have evolved
- Data table of Snail Shell Observations
- Data analysis explanation
- Questions asked during Interview of a Scientist
- Reflective Blog on learning
What sequence of teaching and learning experiences will equip students to develop and demonstrate the desired learning goals? Include agenda and time estimates.
Who/what lived in these fossil shells?
What are molluscs?
Students revisit Gatun Fossil Guide,
Pair-Share: What are Gastropods and Bivalves?
Use diagram to add notes on Mollusc Classes: bivalve, gastropod, cephalopod
Q: How are they similar to each other? How are they different?
Q: What are some familiar molluscs living today? (land snails, squid)
Video Clips: Shape of Life: Mollusc Animation: Abalone Body
Common structures: shell, radula, foot
FOCUS QUESTION: Why do molluscs make so many different shell designs?
- Read Aloud to partners: MOLLUSC FACT SHEET
- Video Clips: Shape of Life: Mollusc Animation: Shell Repair
- Pair Share: What is a mollusc? Where do their shells come from?
PLANNING AN INVESTIGATION
Focus Question: Why do molluscs make so many different kinds of shells?
Hypothesis Pair-Share: Students offer best guess of an answer
Focus on protection and defense
Q: How could we test this idea? Compare gastropods
Tools: caliper, fossil guide, bag of 8 different shells, magnifier
Measurements: thickness of shells
Data: Defensiveness scores
INVESTIGATING SNAIL SHELL DESIGN
Introduce Gastropod Anatomy diagram and vocabulary
Example: How to score, show for one shell, enter data in table
Continue with group work
FOCUS QUESTIONS: Which kind of gastropod shell has the best design to defend itself against predators? In what ways do different snail shell designs “solve a problem”?
Video Clip: Shape of Life: Pycnopodia Chases Abalone
Video Clip: Shape of Life: Moon Snail Preys on Cockle
INVESTIGATING SNAIL SHELL DESIGN
Groups continue work examining and assigning defense scores to Gastropods
Share out from groups: Which gastropod scored the highest? Which the lowest?
Look closely at shells with doc camera to describe defensive features
REFLECTION ON SCIENCE PRACTICES
Q: Which Science Practices were you doing today with your group?
(Conducting an investigation, Engaging in Argument from Evidence, Analyzing Data)
FOCUS QUESTION: What is an “evolutionary arms race”?
Turn in labs with Data Tables for grading
VIDEO NOTES: The Survival Game (15 mins)
Pair-Share, Class discussion on information learned
READING A SCIENCE ARTICLE
Silent reading of “An Interpretation of Vermeij’s Data” with underlining
Teacher Read Aloud with Graphs on Doc Camera
Key vocabulary—predator, prey, coevolution
FOCUS QUESTIONS: What is coevolution and how is it “an arms race”?
What evidence do scientists use to explain coevolution of molluscs and their predators?
Review Graphs of Vermeij’s Data
INTERPRETATION OF VERMEIJ’S DATA
Class discussion of graphs, answer questions within article
*QUESTIONS ABOUT CONE SHELLS
Prepare to interview a scientist
Video clip: You Tube: Deadly Cone snail
Students brainstorm and list what to ask during Skype interview
FOCUS QUESTIONS: What can be learned from cone snails? How similar are ancient and modern marine snail designs? How do you interview an expert scientist?
Add to questions about Cone Snails
INTERVIEWING A SCIENTIST—Dr. Jonathan Hendricks, Professor of Geology
Summary of why he went to Panama, what he found out
Slides showing Cone Snails with Colors and Patterns
DEMO: Gatun cone snails under a UV light
Q: What can the patterns tell you? Which kind of cone snails do we have in our collection?
FOCUS QUESTIONS: How did you use Science Practices while studying fossils? What have you learned about what paleontologists do? What have you learned about why molluscs have so many different shell designs?
Get notebooks and iPads ready
Write about the Focus Questions and add it to your Digital Portfolio
Reading | Writing | Speaking | Listening Strategies
- Students read a Fossil Guide, a Fact Sheet and a science article for information.
- Students write short explanations to answer focus questions in their Science Notebooks, to draw conclusions about an investigation, and later to reflect on learning in a Blog.
- Students regularly do verbal Pair-Shares and speak with peers in groups
- Students ask a scientist their questions about cone snails.
- Students listen to teacher explanations, video clips, and to a scientist’s answers to their questions.
Prior Knowledge needed for this lesson (or to be revisited):
–Science & Engineering Practices
–Familiarity with Gatun fossil shells
–How to use a Fossil Guide
–What a fossil is
–What a paleontologist does
Same as objectives listed above.
Future Skill Connections
–Writing a Reflective Blog about science learning
–Using fossils to build a record of Earth’s history
–Understanding the geologic time scale
–Explaining extinction and its causes
–Understanding the process of natural selection and evolution
–Creating phylogenetic trees based on common ancestry
–Biomimicry as inspiration for engineering design