Name:___________________________

Coevolution Models

Coevolution is where two or more species reciprocally influence each other and their evolution of various adaptations. Coevolution is similar to an arms race: as one species develops a dense against another species, the other species adapts to that other species adaptations. Evolution can be driven by a number of factors, biotic, abiotic, and luck. The survival of a species coevolving with another is dependent on the population size, the mutation rate, and the pressure on the population to adapt. This class activity will use NetLogo to mimic coevolution between bugs and birds in various scenarios.

Link to model: http://netlogoweb.org/launch#http://netlogoweb.org/assets/modelslib/Curricular%20Models/BEAGLE%20Evolution/Bug%20Hunt%20Coevolution.nlogo

Video explaining a famous coevolution example:

https://oeta.pbslearningmedia.org/resource/tdc02.sci.life.evo.leaf/ancient-farmers-of-the-amazon/

1) Open netlogo

2) Find “Bug Hunt Coevolution” in the Models Library under Beagle Evolution Folder.

3) Click on the Info tab at the bottom of the pate and read about the model

a. What does this model show? (in your own words)

b. What is the INITIAL-BIRD-VISION AND INITIAL-BUG-VISION?

c. How does vision help in a predator-prey relationship?

4) Click on the “Code” tab and scroll through it. What do the different colors of the bugs indicate?

5) For initial setup, these are the original settings for future reference:

a. Number-bugs: 30

b. Number-birds: 10

c. Wiggle? On

d. Show-vision-cone? On

e. Bug-flee-strategy: nearest

f. Bug-pursuit-strategy: nearest

g. Initial-bug-speed: 2

h. Bug-speed-mutation: 1

i. Initial-bug-vision: 0

j. Bug-vision-mutation: 0

k. Initial-bird-speed: 2

l. Bird-speed-mutation: 1

m. Initial-bird-vision: 0

n. Bird-vision-mutation: 0

6) Go back to the Interface tab. Click “Setup”, then click “go”.

a. Let the model run for 10,000 ticks

b. Screen shot the results and paste it here.

c. How many bugs were caught?

d. What happened in the plot “Avg. Speed vs. Time? (to see what the indicate, right click on the plot and select Edit. This will define the variables.)

i. Why?

e. What happened in the plot “Avg, Vision vs. Time”? Why? (hint, look at your settings.)

7) Using the sliders, change the “initial-bug-vision”, “initial-bird-vision”, “bug-vision-mutation”, and “bird-vision-mutation” to 0.5. Click “Setup” and “Go”

a. Run the model for 15,000 ticks.

b. Screen shot the results and paste it here.

c. How many bugs were caught?

d. What happened to the bug vision compared to the bird vision?

i. Why do you think this happened?

e. How did the speed of both species change over time?

8) Using the sliders, change the “”bug-speed-mutation” and “bug-vision-mutation” to 0. Click “Setup” and “Go”

a. Run the model for 15,000 ticks

b. Screen shot the results and paste it here

c. How many bugs were caught?

d. What happened to the bug vision compared to the bird vision?

i. Why do you think this happened?

e. Comparing the results to #5, what does this tell you about mutation rate and coevolution?

9) Let’s move to exploring mutation rates about speed. Reset everything to the original setting as stipulated in #5. Now change the bug-speed-mutation to 0 and bird-speed-mutation to 0

a. Run the model for 15,000 ticks (remember to click setup before running the model)

b. Screen shot the results and paste it here

c. How many bugs were caught?

d. Based on the color of the bugs after 15,000 ticks, what speed were they at?

e. Will the speed ever change if you run the model for longer than 15,000 ticks?

10) Now change bug-speed-mutation to 0.5.

a. BEFORE RUNNING THE MODEL: What do you think will happen to the bug speed evolution if bugs have a speed mutation rate and birds don’t?

b. Click setup and go.

c. Run the model for 15,000 ticks (remember to click setup before running the model)

d. Screen shot the results and paste it here

e. How many bugs were caught?

f. Based on the color of the bugs after 15,000 ticks, what speed were they at?

g. What happened to the bugs evolution? Why did this happen? Was it what you predicted?

11) On your own, develop your own scenario:

a. Number-bugs:

b. Number-birds:

c. Wiggle?

d. Show-vision-cone?

e. Bug-flee-strategy:

f. Bug-pursuit-strategy:

g. Initial-bug-speed:

h. Bug-speed-mutation:

i. Initial-bug-vision:

j. Bug-vision-mutation:

k. Initial-bird-speed:

l. Bird-speed-mutation:

m. Initial-bird-vision:

n. Bird-vision-mutation:

o. What is your prediction for how the bugs and birds evolve?

p. How long did you run the model?

q. Screen shot your results and paste here:

r. How many bug were eaten?

s. Explain what happened to your populations and their mutations.

12) Save this document and upload it to blackboard for grading.