Natural Selection in the Wild Pre-Requisite
Lesson 2 of 8
Objective: Students will be able to analyze experimental data to show how some traits are more advantageous than others.
Purpose of Lesson:
The purpose of this lesson is to broaden the student perspective from one type of trait on one organisms in the computer simulation, to a trait that has a myriad of variations, the bird beak. As the unit continues, the students will continue to add complexity to their thinking looking at several traits at a time.
Major Strategies to Watch for:
1) Vocabulary Protocol - This is a collaborative method of preloading vocabulary for the mini unit.
2) Clipbird Lab - In this lab from the University of Berkeley, students get to see how a trait affects the survival of organisms over generations.
Ready. Set. Engage!
Learning Goal: Examine how over time adaptations can become more prevalent in a population.
Opening Question: How old do you think the Earth is? How long do you think life has had to evolve on Earth?
My purpose in asking this question is to find out where students are in understanding geologic time. If students don't have an understanding of the immensity of geologic time, than they will struggle to imagine natural selection taking place over billions of years. Today, I elicit student answers and then have them choose one of these as the age of the earth.
- A few thousand years
- A few million years
- A few billion years
Today, I do not give the students the answer but I hold onto the question and use that information in later lessons.
Students record their opening question/response on their learning goal sheet and are ready to start class 3 minutes after the bell has rung. I reward students who get started early with ROCK STAR SCIENTIST tickets.
Today's video hook, Adaptations: Different Beaks for Different Diets, is an interesting video produced by a couple who were running the length of South America to raise awareness of threatened ecosystems, meet and learn about the people of South America, and get to have an epic two-year running adventure in the wild. You can follow their adventure online.
I'm showing this video on different beaks to introduce the ClipBird lab we will do in class. I ask the students to watch the video and look for a relationship between the structure of the beak and the type of food. After the video, I ask students to discuss this relationship at their table. Then I pose the question, "How do the birds get just the right beak they need for the food they eat?" Students get a small amount of time to think and discuss and then we get ready for the vocabulary activity.
Now that students are ready to learn about adaptations it is a perfect time to introduce some vocabulary words. I use a multimodality strategy to introduce only about five to seven words, and do this in collaborative groups of four with each person having an assigned job.
1- Word person- states what they already know about the word or what the word means to them.
2- Image person- States what they think about the picture and what it means to them.
3- Definition person- Reads the definition and states what it means to them.
4- Sentence Person- Reads the sentence and states what it means to them.
I project the presentation on the board or put individual copies at the desks.
I use a timer and a bell. Each person gets 15 sec for their role. In the beginning of the activity the students need to be trained on what to do and it helps to give them some sentence starters, like "This means..." "When I hear this I think..."
After each person has rotated through their roles for the first word, I give the students 1-2 min of independent time to make their TIP charts (Term, Information, Picture) for that term. Then we move on as a class to the next term. Later in the year, when students are familiar with the process this can be released to them to manage their time. But in the beginning I manage the time to keep the class on track.
This work has meaning and purpose. Students keep these homemade glossaries in their folders and can use them on all the work we do in class including tests and quizzes. This is a great resource for them to use the rest of the year!
Below is a picture of the slide for the word "mutation" and a video of a student discussion.
The purpose of this section is to give students a second simulation process, this one that involves more student activity. The previous simulation can be found in the Discovery section of this unit.
The Clipbirds lab comes from the University of California Museum of Paleontology. In this lab students are using different size binder clips to eat different food. It is actually the second lab in a series on Natural Selection. In the first lab, students simulate competition using different types of beaks. That lab, Battle of the Beaks is also great fun if you are just trying to show how different beaks compete for food. Today I am concentrating more on variation within a species so I use the Clipbird lab for that purpose.
For the Clipbird lab, students use different size beaks to "capture" food. At the end of each round some of the birds do not survive and the birds that do survive reproduce. Students keep data during each round on the amount of food the birds "catch" and the amount of birds.
Closing Statement: Today we did another simulation showing traits can change over time.
Closing Question: What become more clear to you about Natural Selection today?
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.