• Answer the Questions in Part A of Lab 7 Lab Report.
• Answer the Questions in Part B of Lab 7 Lab Report.
Co-evolution: Predator- Prey Interactions
1. 400 beans of four different colors will be scattered. The beans represent a prey population with considerable color variation (white, red, black and brown). For the first simulation, the numbers of each of these color variants are equal in the prey populations (100 of each).
2. Individual students will represent the predator population. The predator population will have structural variations for acquiring prey, just like different individual birds have slightly different shaped beaks.
The variations will be the tool used to gather the prey.
Group A: Forceps
Group B: Fork
Group C: Spoon
Group D: Knife
Think of this tool as the appendage, such as a beak or claw shape the predator was born with. Other than this variation, the predators are alike.
3. When instructed, begin hunting using your tool to gather prey into the cup you have been given. The cup represents your stomach.
No scraping or pushing of the prey into the cup is allowed and your cup may not touch the ground or table top. Remember that the more prey you capture, the more likely it is that you will be strong, healthy, and able to mate!
4. When instructed to stop, you must stop immediately. Count your "kills" (beans in the cup) and sort them by color. If you are in the process of a kill when told to stop, you must stop!
5. Record your data in your lab report and on the classroom tally on the board. This data represents one generation. You may following these rules to determine if your adaptation is successful.
a. If you have caught 10 or more prey, you survive and produce 2 offspring.
b. If you caught between 5-9 prey, you survive and produce 1 offspring.
c. If you caught 2-4 prey, you survive but do not reproduce.
d. If you caught less than 2 prey, you starve.
Based on this data, the predator and prey populations will be reconstructed for the next round/ generation. Analyze your classroom data. What color prey was "killed" most often? Which color adaptation led to increased survival? What do these numbers mean? As a class, determine how to set up the simulation for the next generation. In your class discussions, keep these questions in mind:
Would any population, color of prey, variety of predator, be considered extinct after this generation?
How will you represent reproduction in the prey population?
How will you represent reproduction in the predator population?
6. Set up the second generation based on your results. If time permits, you may simulate up to four generations.
Tally the classroom results in your lab report and answers the remaining questions in your Lab Report.
7. Fill in the tables and answer the questions in your Lab Report.
Suggestion for setting up generations 2-4.
Keep the population of prey at 400 individuals by using the % survived for each color variation. For example, if 10% of the white beans survived the next generation would have only 40 white beans (10% of 400).
There are two ways you can keep the Predator population with the same number of individuals. This way every student can still participate in the“kill”.
The simple way is to use the % killed for each killing tool. So, if 70% of the kills were by the spoon and there are 24 students in the class there would be 16.8 (round that to 17) spoons in the next generation.
The more complicated way is to use the information above stating if you survive and how many offspring you have and then determine the percent for each of these and use that percent to distribute killing tools to every student for the next generation.