Andrea Pless EVERITT MIDDLE SCHOOL, WHEAT RIDGE, CO
7th Grade Science : Unit #11 - Adaptation: Natural Selection in the Wild : Lesson #1

Natural Selection in the Wild Discovery

Objective: Students will be able to use a computer simulation to model natural selection.
Standards: MS-LS4-4 MS-LS4-6 SP1 SP2 SP3 SP4 SP5 SP8
Subject(s): Science
60 minutes
1 Teachers' Lounge - 0 minutes

Purpose of Lesson:

The purpose of this lesson is to let students apply the concept of natural selection to a limited situation. As we move through this unit, students broaden their focus until they are analyzing several adaptations in a real population.

 

Major Strategies to Watch for:

1. Video lesson -  I use a short video that showcases me, teaching this lesson. By showing a video to the students, I free myself to walk around and interact with students.

2. Computer simulation lab -  Students use a computer simulation to ask questions, take and analyze data and make conclusions.  

2 Ready. Set. Engage! - 5 minutes

Learning Goal:  Discover the ideas of Natural Selection at work in a computer simulation. 

Opening Question: What does the word "advantage" mean in natural selection?

Today, I'm interested in hearing from the students what traits they think might be advantageous to survival.  I let the students answer out loud to the whole class and build off of each other's answers.  At the end of the class I go back to this question and connect it with the simulation asking them what trait was the most advantageous in the simulation.

Students record their opening question on their learning goal sheet and are ready to start class 3 min after the bell has rung.  I reward students who get started early with ROCK STAR SCIENTIST tickets.  

Follow the links to learn more about the beginning of class strategies and ROCK STAR scientist tickets.   

3 Hook - 5 minutes

For the hook today, I want students to have a preview of the simulation we are going to use. I show this self-made video to introduce them to the parts of the simulation. Using a video like this, instead of teaching it myself, gives me the freedom to walk around the room and help struggling students. If the whole class needs to catch up, I can stop the video, check for understanding and then go on. Sometimes, having short taped lessons can free you to help individual students and keep the class going at pace.

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At the end of the video, students have used their own computers to get to the site and now understand the basic premise of the lesson. I ask all students to stop and shut their computers for the next part of the lesson.  

4 Pre-assessment - 5 minutes

I start each unit with a pre-assessment to open up the student thinking and help uncover misconceptions. This allows be to modify my teaching, compact curriculum, form appropriate groups, and measure growth. By far the best formative probes I've found are by Page Keeley. She's written several books such as Uncovering Student Ideas in Science Volume 1, 2, 3 and 4. In this probe, Habitat Change, students learn about an small animal living on an island. The habitat goes through a drastic change and the students have to decide what will happen to the animal. This gets directly at the misconception that many students have that organisms can adapt at will.  

The student work shows that the student does have a strong idea that the animal will probably die. However, he also states that the animal could change behaviors to survive. This shows that they didn't connect to the other aspects of the habitat change, the lost of leaves and ants. This student is ready to learn this unit where we will focus on adaptations and survival. 

Pre-Assessment
Checks for Understanding

In the past, I haven't been the biggest fan of pre-assessment.  It seemed to me that most of my students came to me with pretty much the same level of knowledge about science (low) and the process of science (even lower).  I felt like assessing that up front was a waste of time because I already knew they didn't know anything.  It seemed to me that one of the worst ways to use pre-assessment was to give the test at the beginning of the unit (check- they know nothing) and then give the test at the end of the unit (check- They learned! Growth!)

Recently, my ideas about this have changed greatly and I now think that pre-assessment is much less about proving growth and much more about uncovering though processes.  This is why I like the Page Keeley books so much.  Every probe is carefully designed with common misconceptions in mind and they help show where students are in the core concepts.  These probes are truly meant not to MEASURE instruction but to INFORM instruction. 

One method for planning instruction after use is to use a percentage system like below;

10% of students have a misconception-  Call in those students individually for a conversation to probe for thinking.

10-30% of students have a misconception- Pull small groups during class to address the thinking using an activity.

30-50% Organize a tiered lesson with different objectives.

Over 60%- Consider more universal instruction using problem based learning, a discrepant event, or a guided analysis lab.  

5 Discovery Activity - 10 minutes

I love having my students use computer simulations to do "real" lab reports. I believe this helps students to also understand computers as tools instead of only as gaming devices. In this lab, the students are going to use the simulation to predict how the organism will change over time.

Students can work individually or in partners for this lab. I think it is best practice for students to work with one other person so that they can have critical thinking discussions.

This evolution simulation involves creatures with head grabbers eating flies. In the Natural Selection Lab, students are only going to take data every five rounds. This reduces some of the tedium of data recording and speeds up the lab. Students are asked to graph the data in the way they think it is best displayed. It is always interesting to see which students simply copy one of the graphs from the simulation and which choose to create their own method. Either way is fine because I am more interested in the discussion of WHY they chose to represent the data in that way.  

Once students are done with the labs and graphs, students should answer the conclusion using the sentence starters. I've put the sentence starters on the lab, but at some point you should start taking the sentence starters away for the students. I have found that unless students have to do their OWN thinking on exactly what to write, how, and why, they never truly become proficient conclusion writers.  

In this video a student discusses using the simulation and what they learned about natural selection from the simulation.

Link

6 Discussion - 7 minutes

The purpose of this section is to process the lab as a whole class.  

There are many important points in the simulation that need a check for understanding. I am most concerned with whether students understood how the organisms changed and why they died. Some of the questions I ask the class are:

  • How many organisms died every turn? Is that like real life?  
  • How did an organism get to live the longest?
  • What trait helped an individual survive?
  • How did they get that trait?
  • Did ALL the individuals with long grabbers live? Why or why not?
  • How did the species change over time?  Did individuals change the size of their neck?
  • If every round takes 1 year, how long does it take for most of the organisms to have a grabber that reaches 3 or 4 boxes?
  • What if a giant catastrophe kills all the flies but allows the organism to eat worms? How would this change effect the selection process of the species? Why?
7 Closure - 2 minutes

Closing Statement: Today we studied an evolution simulation on the computer.  

Closing Question:  What trait was advantageous in the simulation?  How is this like real life?  How is this NOT like real life?  

Closure depends greatly on timing and is not as easy to plan in advance as opening.  You can find more information about how I manage closure here.