Lesson 2Title: How do organisms respond to changes in their environment?

Grade Level: Third Grade

Benchmarks:

Next Generation Science Standards

(3.EIO.d) Use models to evaluate how environmental changes in a habitat affect the number and types of organisms that live there; some remain, move in, move out, and/or die.

(3.EIO.e) Use evidence to argue that some changes in an organism’s habitat can be beneficial or harmful to the organism.

Common Core State Standards

(CCSS.Math.Content.3.MD.B.3) Draw a scaled picture graph and a scaled bar graph to represent a data set with several categories. Solve one- and two-step “how many more” and “how many less” problems using information presented in scaled bar graphs. For example, draw a bar graph in which each square in the bar graph might represent 5 pets.

“Place holder” - Potential to add standards and objectives related to visual art appreciation and to develop an opportunity for students to respond in writing to the camouflage art of Lui Bolin. See engagement activity.

Objectives:

TLW use models to show how environmental changes affect the number and types of a species that live there. (3.EIO.d)

TLW use models to show how environmental changes can benefit or harm a population based on organism characteristics (adaptations). (3.EIO.e)

TLW draw a scaled bar graph based on data collected from a scientific model which represents changes in a population of animals over time. (CCSS.Math.Content.3.MD.B.3)

Materials and Setup:Engage:

Camouflaged animal pictures for projectionExplore/Explain:

access to http://phet.colorado.edu/en/simulation/natural-selection one computer for each group of two students

“Natural Selection PhET Simulation” worksheetElaborate:

one piece of graph paper for each student

Vocabulary:

Camouflage – an adaptation that helps an organism blend into their environment and avoid detection by predators

Procedure:

Engage:

Teacher says, “Let’s start today by looking at some pictures of animals in their habitats. Someone remind me what a habitat is.”

Students respond.

Teacher says, “And we have groups of habitat experts with us in the class today. Where are my ocean habitat experts? Desert? Forest? Tropical rain forest? [See lesson 1 for habitat groups.] Alright. I brought some pictures of animals that I will put up on the screen. As soon as you see the animal, put your pointer finger on your nose.”

Teacher shows pictures of camouflaged animals in a habitat.

#1 Zeeland fur sealhttp://www.socsdteachers.org/~kchristieblick/2007_01_01_mscbnz_archive.html

#2 Frog http://coveredbyhishand.wordpress.com/2010/05/11/camouflage-frogs/

← #3 Froghttp://coveredbyhishand.wordpress.com/2010/05/11/camouflage-frogs/

#4 Artist Lui Bolin Liu Bolin, Hiding in the City No. 71 - Bulldozer, 2008

#5 Moth imageDan L. Pearlman, EcoLibrary.org http://www.ecolibrary.org/page/DP84

← Teacher says, “Some animals have special characteristics, which allow them to survive and reproduce in their environment. The animals in these pictures are camouflaged. How would that help them survive?”

Students respond, “It helps them hide from things that want to eat them.”

Explore:Teacher says, “We’re going to continue discussing organisms and their habitats today by playing with bunny rabbits… virtual bunny rabbits. After playing with the virtual rabbits, I will expect you to answer the following questions:

How do changes in the environment affect the number and kind of organisms that live there? (3.EIO.d)

How do changes in the environment benefit or harm certain organisms? (3.EIO.e)

I will let you play with the simulation for five minutes so you can become are comfortable with the controls, and then we will get started analyzing the bunnies in order to answer questions and complete challenges on the worksheet (“Natural Selection PhET Simulation” Worksheet). We will work in groups of two, and the group members will work as a team to complete and turn in the worksheet. One student will drive the pointer with the mouse. The other student will navigate by telling the other student what to click on or try. The navigator should also write the responses on the worksheet. After completing an activity, the driver and navigator will exchange jobs.”

Instructions for students

Log on to: http://phet.colorado.edu/en/simulation/natural-selection or open the simulation if you downloaded it to your computer. Make sure your computer or sound system is turned ON.

Names: ____________________

Natural Selection PhET Simulation

1) Play with the simulation for five minutes. Be prepared to share what you have found!

2) Fill in the table below with your observations.

How can you… What did you change? How many generations did it take?

…make more white bunnies?

…make 20 brown bunnies?

3) Challenge 1: Find a way to make the bunnies take over with brown fur! Fill in the table with your selections.

Note: A “Selection Factor” in this simulation and on this worksheet is the answer the question “What did you change to affect the bunny population?”

Mutation Environment Selection Factor Observations

4) Challenge 2: Find a way to make 200 bunnies when food is a selection factor! Fill in the table with your selections.

Mutation Environment Selection Factor Observations

5) Challenge 3: Find a way for the bunnies to take over when the environment is the artic! Fill in the table with your selections.

Mutation Environment Selection Factor

Observations

6) On your own: Simulations are useful for understanding how natural processes work but are not always representative of the real world. How does this simulation differ from what might happen in a true ecosystem?

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7) On your own: What changes would you make the simulation to make it a better representation of a true ecosystem?

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Explain:

[Formative Assessment (3.EIO.d): Students explain their findings on the simulation and describe how environmental changes affect the number and types of a species that live there by answering the following questions as the teacher walks around and observes the groups. Some of these questions appear in teaching resources associated with the online simulation provided for classroom use by UTeach Outreach, and are included here for convenience]

1. What are a few differences between the desert and arctic environments? 2. Why do you think the wolves eat the white bunnies in the desert

environment? 3. What is missing from this simulation’s representation of a desert (arctic)

environment? Different predators, seasonal changes, different types of food.

4. What does the graph show? The number of bunnies in a population, how many bunnies have each trait.

5. What happens when you add the selection factor of Food, versus having No Factors?

6. Why do you think more bunnies die each generation with food, than without food? There is not enough available for all of them; they fight for food.

7. How does the simulation environment differ from a real wilderness environment? Limits predators to only wolves. Doesn’t allow for both food and predators at the same time. Doesn’t have seasons and weather changes.

8. What parts of the habitat are living? The bunnies. The wolves. The food.9. What parts of the habitat are not living? Climate/sunlight/weather. 10. What strategies did you use to answer the challenges? Study one mutation

at a time, wait lots of generations. Trial and error, thinking about what we have done in science class before.

11. If you were a scientist, when would a computer simulation be useful? To study things that are challenging to study in real life, to collect lots of data.

[Summative Assessment (3.EIO.e): Natural Selection PhET Simulation worksheets are used to assess the ability of the students to manipulate environments to affect bunny populations in beneficial and harmful ways. ]

Elaborate/Extend:

Using a graph of the bunny population from the simulation, have the pairs of students practice creating bar graphs of the bunny population at different times. Looking at a sample graph, students describe which changes in an environment could have caused changes reflected in the bunny populations represented on the bar graph.

[Formative assessment (CCSS.Math.Content.3.MD.B.3): Using the following graph from a simulation, students produce a bar graph with population on the y-axis and time on the x-axis. Students draw four bars at four different times (in order of occurrence) representing increases and decreases in the bunny population over time.]

Scientific Background for the Teacher

“Animal Adaptations to the Environment”, Smith, Thomas M., and Robert Leo Smith. Elements of Ecology. 8. United States of America: Pearson , 2012. 119-147. Print.

“Descent with Modification: A Darwinian View of Life”, Campbell, Neil, Jane Reece, Lisa Urry, Michael Cain, Steven Wasserman, Peter Minorsky, et al. Biology. 8th. San Francisco, Boston, New York: Pearson Education, 2008. 452-467. Print.

“The Evolution of Populations”, Campbell, Neil, Jane Reece, Lisa Urry, Michael Cain, Steven Wasserman, Peter Minorsky, et al. Biology. 8th. San Francisco, Boston, New York: Pearson Education, 2008. 468-486. Print.

“Population Ecology”, Campbell, Neil, Jane Reece, Lisa Urry, Michael Cain, Steven Wasserman, Peter Minorsky, et al. Biology. 8th. San Francisco, Boston, New York: Pearson Education, 2008. 1174-1197. Print.

Resources

Internet

PhET Simulation on Natural Selection http://phet.colorado.edu/en/simulation/natural-selection

The PhET exercises in this lesson were adapted versions of a 7th grade lesson developed by UTeach Outreach in Spring 2012 which can be found at http://phet.colorado.edu/en/contributions/view/3578.

The “Natural Selection PhET Simulation” worksheet embedded in this lesson can be found with an answer key at http://phet.colorado.edu/en/contributions/view/3578.

Books

Hard to See Animals http://www.scholastic.com/teachers/book/hard-see-animals

Camouflage art

Liu Bolin, Hiding in the City No. 71 - Bulldozer, 2008 http://www.ekfineart.com/artist/Liu_Bolin/works/