Evolution Lab – A New Beak How did such a wide diversity of beaks evolve? To find out, you’ll try a new twist on an old favorite: A simulation of bird beak evolution! Comparing bird beak designs through simulated food competition is an old evolution lab standby. Often, evolution lessons model and compare the effectiveness of different adaptations, testing models to determine the best one. But why stop there? Genetic variation doesn’t! Genetic variation is the process (by mutation, diverse mating, and other means) by which genetic differences are introduced into a population. Changes build on each other, positive or negative, and genetic variations occur to a baseline that itself was changed, for better or worse, in previous generations. Evolution can move much faster than we think! Adaptations arise over long and short horizons, from multiple sources such as diversity, mutation, environmental conditions, mating patterns and more. Adaptations appear and are tested in the natural environment, and populations that display more helpful traits often have a stronger record of survival. In this activity, success can build on successful variation, allowing you to participate in an exercise on competition, where successful designs are given greater opportunities to adapt and improve. In nature, these changes arise through the confluence of random chance, external conditions, and internal changes such as mutation. Part 1: Design A Bird Beak How do bird beaks, bills, and rostrums work? Actually, they’re just like our jaw! There is an upper and lower mandible that open and close to capture and consume food. Using the design thinking steps outlined below, you will research, design, and build a beak that you think will be good at capturing and consuming food. Working through this process will take the majority of one class period. a) Design and build a beak. Using the following materials, begin the process of designing and prototyping your bird beak. As you work, step through each of the design thinking steps, recording your process. Beak Making Materials: Tape (masking, clear, duct, or whatever you have in your classroom) Scissors Glue Card stock Cardboard Popsicle sticks Rubber bands Paper clips Plastic forks Plastic spoons Part 2: Test Your Beak! You are going to test how well your designed beak can consume different food types and model evolution by natural selection at the same time. You will have 15 seconds to collect as much food as possible. Birds that forage more effectively have more energy and less disease and parasites, and therefore they are more likely to reproduce successfully and bear more offspring. In this simulation, the amount of “food”, and the quality of each food type, will determine how many offspring you are able to produce. The number of offspring you produce determines how much genetic variation (represented as build and redesign time) you will move forward with for the next round of “natural selection” (testing). In other words, more successful beaks will get more food and will be granted more time to implement improvements. Thus, the real-world impact of additional offspring is represented in the lab by additional time for modifications to your design before another round of testing. After multiple rounds of testing, your beak design will likely “evolve”! Why do successful beak designs earn more redesign time? Remember: you are modeling the process of mutation, natural selection, and evolution a process that occurs by chance—in the example of the Galapagos finches, the weather events that created the conditions for evolutionary success of a certain beak type were random and unpredictable, and other events could have led to other outcomes. The process of iterative design in this lab is meant to illustrate the selective advantages that can occur through from random mutation. The effect of such events is modeled by the design choices you made, however the real-world phenomenon of genetic variation occurs by chance! Feeding Simulation Setup Materials Dixie cups (20-30) Lab Handout pencil Bird “Food” Lab Setup Dixie cups, each filled with an equal amount of one type of “bird food” An empty cup for each beak tester as a collecting cup for gathering consumed “food” A flat plate or tray where “bird food” will be spread out for each test Testing Procedure 1. Pour the first bird food type onto the tray. 2. When the time-keeper says go (and starts the stopwatch), the beak-tester has 15 seconds to “eat” as much food as possible by using the beak the collect food and place it into the collection cup WITHOUT using any part of their hands, only the beak! 3. After 15 seconds is up, record the amount of food on the group’s data table in the row for that food type, spilled and dropped food does not count! 4. Repeat steps 1-3 for each food type using the same beak. 5. Use the beak evolution lab guide to calculate the number of offspring your bird beak earned, and then calculate how much redesign time you earned to modify the team’s beak. Look at your data and answer the reflection questions on the beak evolution lab guide. 6. Keeping track with the stopwatch, make any changes you want to the design of your beak within the amount of redesign time that you earned! The documentarian should record the changes made to the beak design with a photo, video, or labeled sketch. 7. Repeat steps 1-6 at least three times, to test the new beak design.