EXPLAINING SNAIL SHELL DESIGNS

TEAM

karen JONH
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?

Intended Audience

Middle School

8th Grade Integrated Science

Time Frame

6-7 hours (3 block periods or 6-7 short class periods)

Standards

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.

LS4.C:  Adaptation
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:

Patterns
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.

Mathematics:

6.SP.B.5 Summarize numerical data sets in relation to their context.

Resources & Materials

Diagrams

Mollusc Family:

http://palaeos.com/metazoa/mollusca/images/mollusc_classes.jpg

Gastropod Anatomy:

http://www.uwosh.edu/faculty_staff/hiatt/Teaching/Historical/gastropod_parts.jpg

Graphs by Geerat Vermeij with explanations and writing prompts

http://shapeoflife.org/lesson-plan/sol/shell-shocked-lab-activity-snails-vs-shell-breaking-predators-middle-school-lesson

Student Worksheets

See Shape of Life “Shell Shocked” Lab Activity (can be adapted for ELs)

http://shapeoflife.org/lesson-plan/sol/shell-shocked-lab-activity-snails-vs-shell-breaking-predators-middle-school-lesson

Articles

Mollusc Fact Sheet:

http://shapeoflife.org/sites/default/files/global/Mollusc-Factsheet.pdf

“An Interpretation of Vermeij’s Data” (adapted from Shape of Life’s “Shell Shocked”)

http://shapeoflife.org/lesson-plan/sol/shell-shocked-lab-activity-snails-vs-shell-breaking-predators-middle-school-lesson

Video clips:

Shape of Life: Mollusc Animation: Abalone Body Plan

http://shapeoflife.org/video/mollusc-animation-abalone

Shape of Life: Mollusc Animation: Shell Repair

http://shapeoflife.org/video/mollusc-animation-shell-repair

Shape of Life: Pycnopodia Chases Abalone

http://shapeoflife.org/video/molluscs-pycnopodia-chases-abalone

Shape of Life: Moon Snail Preys on Cockles

http://shapeoflife.org/video/molluscs-moon-snail-preys-cockles

Shape of Life: The Survival Game

http://shapeoflife.org/video/molluscs-survival-game

You Tube: Killer Cone Snails (National Geographic)

 

Informative websites:

Video resources about The Story of the Animal Kingdom:

www.shapeoflife.org

Blog about cone snails by Jonathan Hendricks:

Panamanian Fossil Record of the Killer Cone Shells

Atlas for information on fossil mollusk species:

http://neogeneatlas.org/

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

Photos

Images of cone snail patterns under UV lamp

http://neogeneatlas.org/wp-content/uploads/Conus_adversarius-SO047-1-2000px2.jpg

Guiding questions

  • 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.

Objectives

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

Assessments

  • Data table of Snail Shell Observations
  • Data analysis explanation
  • Questions asked during Interview of a Scientist
  • Reflective Blog on learning

Teaching phase

What sequence of teaching and learning experiences will equip students to develop and demonstrate the desired learning goals? Include agenda and time estimates.

Day 1

FOCUS QUESTIONS:
Who/what lived in these fossil shells?
What are molluscs?

SCIENCE STARTER:

Students revisit Gatun Fossil Guide,

Pair-Share: What are Gastropods and Bivalves?

MOLLUSCS

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

Day 2

FOCUS QUESTION: Why do molluscs make so many different shell designs?

SCIENCE STARTER

  •             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

Day 3

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”?

SCIENCE STARTER

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)

Day 4

FOCUS QUESTION: What is an “evolutionary arms race”?

SCIENCE STARTER

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

Day 5

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?

SCIENCE STARTER

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

Day 6

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?

SCIENCE STARTER

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

Student questions

HENDRICKS’ RESEARCH

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?

Day 7

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?

SCIENCE STARTER

Get notebooks and iPads ready

REFLECTIVE BLOG     

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.

Learning Progression

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

Current Knowledge/Skill

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

 

 

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