Evolution and Adaptation

I think it is important for students to understand the history behind the concepts we study and for them to recognize that these were at one point new discoveries.  

I begin this lesson by asking students the following question: Who is Charles Darwin and what was his contribution to science?  I have students share their responses, though the majority of students will be able to relate Darwin to evolution. To give students a mental picture of Darwin and his contribution I show the Evidence of Evolution video. (On a side note, if you have never used a Paul Anderson video in your class you are missing out on a great resource. He has tons of videos on so many topics - including NGSS.)

After viewing the video, I have students read Theory of Evolution By Natural Selection from CK12 which build off of the same information and provides students with some other examples. As they read the article, I have them complete the Note Taking Sheet. Students have used this before and are familiar with the format of summarizing what they learned and documenting questions broken up by headings found in the reading.  

This activity, Battle of the Beaks, comes form the University of California Museum of Paleontology, which is an excellent resource on all things evolution.

The materials needed for this activity are:

• scissors
• plastic spoons
• tweezers
• large binder clips
• 4-5 boxes of large paper clips
• 200 large rubber bands
• 4-5 boxes of toothpicks
• 2 cups of macaroni
• plastic cups (best if clear, one for each student)

Note: students will select scissors, plastic spoons, tweezers OR binder clips so the total of all four of those should equal the number of students in your class.  Also, this lab is best conducted outside, though any large open area will work.

Procedure:

Day 1 

1. Have students select either a spoon, tweezer, binder clip OR pair of scissors.
2. Hand each student a plastic cup and the Bird Beak Data Sheet and then have them sit quietly in a large circle.
3. Explain to them that they are now birds. They are very hungry birds. They can only eat with the implement they have selected and they can only use that implement for eating. The cup represents their stomach. It must remain upright at all times. They must hold their beak in one hand and their stomach in the other. They can only place food in their stomachs with their beaks.
4. Explain to them that certain food items will be placed in the feeding area (middle of the circle but spread out evenly towards the students/birds). When you say “go” they are to collect as much food and place it in their stomachs as possible until you say “stop.”
5. Take one of the food items (paper clip beetles) and distribute the clips within the feeding area. Say “go” and allow birds to feed for 1–2 minutes or until all of the food is gone. [NOTE: Depending upon your students you may need to caution about behavior. Even adults doing this activity become a bit more aggressive as the activity proceeds, but obviously safety is foremost. If some students are not responsible enough for this, have them be observers and take notes on the birds’ behaviors.]
6. Once you have said “stop” have students empty their stomachs and count the contents. Hand each a Recording Sheet to fill in. Have them return all food items.
7. Repeat this activity using each of the other food items (toothpick twigs, rubber band worms, macaroni munchies). By the end of the activity, each of the students should have completed his/her row for the beak type and filled in the total amount of food.
8. Pause for a class discussion:
      a) What did you notice about your feeding abilities?
      b) Did everyone with your type of beak have the same success rate with the same foods? Why or why not?
      c) What did you notice about your behavior and the behavior of others?
9. Examine the data: Tally up the class totals for each of the beak types in a grid on the board. Have the students create bar graphs that represent the class total for each of the beak and food types. This can be started in class and continued for homework.

 Note: I do not tell my students the type of graph they need to create as we have been working on the skills they need to determine that on their own. The lesson Student Designed Lab: Graphing the Results has this information if you are interested.

Day 2

1. When all of the graphs have been completed, have students pick up their beaks and stomachs once again and return to their circle. Explain that obviously most habitats have more than one kind of food available. Ask: What will your strategy be if all of the food types are available?
2. Spread out all of the materials into the feeding circle. Allow about 4 minutes for feeding. Gather the data and have students help to sort out the food items once again for clean up.
3. Again continue with the class discussion. What were your strategies? How was this different from the previous eating experiences?
4. Assess student understanding by posing these questions: 

• What would happen if all the bird types we have been working with flew to an island where no birds had been before and the only food type available was macaroni munchies. 
• Which bird beak type would be most likely to be successful? Explain your answer.

Extensions:

Give a food value for each of the food types. Would this change your feeding strategies? How much more of one type of food would you have to eat to equal only one of something else, etc. What would happen if there was a change in the environmental conditions (drought, etc) causing the loss of one of the food items. What would happen to the bird populations?

To conclude this lesson, I show the students Ten Astounding Cases of Modern Evolution and Adaptation from Popular Science (one of my all time favorite resources for science articles that are great for students!) I created this PowerPoint, 10 Astounding Cases of Modern Evolution and Adaptation, with the exact same information just because it is easier to use in class, though I link the original site on my webpage for the students (I like that it links to other resources if the students are interested).

The PowerPoint shows the photograph from the website and asks students to guess what the "astounding" adaptation might be.  Some are absolutely impossible to guess but I think it is fun to see what the students will come up with and it definitely gets them thinking.

The last slide of the PowerPoint asks students to notice the organisms they encounter on a daily basis and look at them through a new lens as they attempt to determine their adaptations and how those adaptations have helped them survive within their ecosystem.  

This is another formative assessment that I grade using a 3 point scale:

3 - Demonstrates strong understanding of the concept.

2 - Demonstrates good understanding of the concept with only minor misunderstandings

1 - Demonstrates poor understanding of the concept with major misunderstandings

If time allows, I show students the following video that depicts the evolution of the eye.  I love how this connects back to our information processing unit where we designed cyborg eyes.  The more ways I can connect concepts to other lessons, especially lessons that students loved, the more likely students are to remember what they learned.