My Science Box

Sources

The Bird Beak Buffet activity is a classic in the teaching of natural selection and evolution. There are hundreds of write ups out there with all sorts of different variations. I first learned about the activity from Kimberly Tanner, currently faculty at San Francisco State University. I found a box of materials to borrow from Chris Giorni of Tree Frog Treks. Then I participated in a workshop with Karen Kalamuck of the Exploratorium Teachers’ Institute.

There are many variations of this activity on the web from many different organizations:

Assessment

1. Collect the students’ graphs and responses to the conclusion questions.
2. Before the activity, have students write a short essay about “what is evolution and how does it work?” These may be collected to give you as the teacher a sense of what their initial understanding may be. After the activity and discussion, have students revise their essay to reflect what they now know about evolution.

Lesson Plan
Day 1 - Introduction

1. Open class with a discussion of what human traits might help a person be more successful (Is it an advantage to be tall? Is it an advantage in America to be blond haired and blue eyed? How about in another country like Africa or Asia?) Leave the interpretation of “more successful” open and somewhat vague. If this seems to controversial for your group of students, then discuss variation in cat or dog traits and what might help a pet survive better (Is it an advantage for a cat to be shy? Is it an advantage for a dog to be friendly?).
2. Lead the discussion towards thinking about what “more successful” really means. Does that mean being more popular or making more money or more likely to live happily ever after? In scientific terms, what matters in the long run is whether you survive, find a mate, and reproduce, passing on your genes to the next generation.
3. Introduce the activity. Pass out the handout and describe the rules.
4. Check that students understand that all the birds are of the same species but have different beak traits. Similarly, all the beans are of the same species but have different color traits.
5. Check that students understand that the birds that eat the most food will have a baby with a similar beak and that the birds that eat the least will die. Similarly, surviving beans (those not eaten) will have one baby with the same color trait.
6. Finally discuss the data collection that occurs after each round. Each student is responsible for counting the number of each type of bean they eat and entering their data on the bird population data clipboards. Once all the bird population data has been gathered, then a volunteer from each group will report their data on the bean population data clipboard. 
7. If data will also be collected in lab notebooks, have students copy or paste the data tables and graphs into their notebooks.

Getting Ready

1. Purchase beans, cups and plastic utensils.
2. Make copies of the Bird Beak student handout for each student.
3. Make copies of the Bird Beak data tables. For each class that will do the activity you should have 3 copies of “_____-Billed Bird Population Data” and 1 copies of “Bean Population Data”. Attach these data tables to the 4 clipboards.
4. On the 3 “_____-Billed Bird Population Data” clipboards, fill in the blanks with “Fork”, “Spoon”, and “Blade”.
5. For each class or students, count out 100 red, 100 black, and 100 white beans and mix them together in a ziplock bag or cup.
6. Optional: mark the feeding ground boundaries with tape or string.

Teacher Background
Perhaps the most important idea in all of biology, or perhaps all of science, is the idea of evolution through natural selection. This idea by Charles Darwin provides the foundation of all of current scientific thinking in life science.

What is evolution? Quite simply, evolution is descent with modification. This includes both the idea that the frequency of a gene will change in a population over time as environmental conditions change and also the idea that new species descend from common ancestors over many generations. Ultimately, evolution can explain the vast diversity of life on this planet and the idea that all life on Earth shares a common ancestor.

Time
15-20 minutes introduction
45-50 minutes activity (The lesson plan is written so that the activity is introduced on one day and actually done the following day. It is also possible to introduce the activity and go through one or two years on the first day and complete the activity on the following day.)
15-20 minutes organize and summarize data
30+ minutes discussion

Inspired by observations of finches on the Galapagos Islands, Charles Darwin came up with an idea that is perhaps the most influential idea in all of science - natural selection. ...

Sources
This activity was adapted from a DNA earring design by Karen Kalamuck of the Exploratorium Teacher Institute and from the “Modeling DNA, the Code of Life” activity by the RAFT Education Department. I recently discovered another write up for this activity by Catherine Ross .

Instructions

1. String the following onto your wire: phosphate – sugar – base – correct number of seed beads (2 for A-T, 3 for C-G) – matching base – sugar – phosphate.
   
2. Onto one end, add: a base – correct number of seed beads (2 for A-T, 3 for C-G) – matching base. Do not push these beads down to meet the others.
   

Getting Ready

• Order beads (they take approximately 2 weeks to arrive from Enterprise Art)
• Organize beads so that each tray contains enough materials for each group of 4-6 students. You may want to precut the wire as well to avoid the delay of passing the spools of wire around the room.
• Optional: write the step by step guide onto the board or photo copy the instructions for each group of students.