Eat Prey Live Practical and Lesson Plan
Summary: The goal of Eat Prey Live is to teach students about how natural
selection functions and to get students thinking about the different factors
that can affect the strength of natural selection.
Introduction
Populations change over time, and one of the strongest forces shaping populations is predation.
As predators hunt prey, they remove certain individuals, and as a consequence, the genes those
individuals carry, from a population. As a result, this changes the distribution of how individuals
look and behave over time.
In Eat Prey Live, students take the role of a predator that hunts dots that move across the screen.
Players begin playing the game by creating a population of dots (prey) of specified size and with
specified trait values, after which they begin hunting dots. The dots vary in speed and agility. The
result of each round is visualized for students at the end of the round so that students can see
how their hunting has affected the distribution of traits. At the end of the game, students can
progress through all the visualizations to see how their population has changed over all the 10
rounds.
After this lesson plan is a work sheet that we will provide for students in class, and they will work
through.
Setting up the practical
This game is best played in groups of students (3-4). Ideally, you should split students into 5-8
groups as this is approximately how many hypotheses students will be able to test in the lab (each
group will be given a different hypothesis).
One student in each group should volunteer to download the free app, and the other group
members will be using the same phone/tablet for the duration of the practical.
After downloading the app, students should play through the game once, selecting all the basic
attributes of the population (highlighted in the white square below).
Figure 1: the population setup screen
After students finish the level, you should engage them in a discussion to see what they observed.
Keep in mind that at this point, it is likely that the distributions that the groups end up with are
very similar. Here are some potential questions to encourage discussion:
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What did you notice happening to your success in catching your prey?
Why do you think it was more difficult to hit the dots over time?
Did any of the traits change over time?
How did speed and agility change over time?
Do you think the membership of your group made a difference in the end result of your
game?
After some discussion, encourage the students to work through the worksheet questions (below).
The first set of questions encourages discussion about how the other choices in the game selection
screen (Figure 1) would affect the population, students hunting behaviours, and therefore, the
strength of selection. This should take about 10 minutes.
Once the students answer their questions, have a class discussion about their answers and why
they think hypothesized those possibilities. These questions and hypotheses are the beginnings of
their experiments. Write the different hypotheses and questions in front of the class. Once these
are complete, ask students which other factors could affect individual hunting patterns and
selection.
Some other suggestions are: using a dominant or non-dominant hand, whether individuals are
gamers or don’t play video games, sex. See if you can encourage students to come up with these
ideas and encourage them to come up with others.
Once there are a number of factors, devise a set of hypotheses with the class (enough such that
each group has one hypothesis), assign a hypothesis to each group, and then ask students to
devise a methodology to test this hypothesis.
At the end of their experiment, ask students to take a screen shot of how their population looked
like at the end of the 10 rounds. Students can then summarize their results and show their
distribution at the front of the class in a 1 minute presentation. Alternatively, you collect each of
the different distributions (through email or texting), and display them in a powerpoint
presentation, smartboard, or projector.
You can then discuss what factors were important in determining whether a trait evolved. There
are three fundamental aspects necessary: variation in traits, that traits are heritable, and some
level of selection. You can then discuss how some of these factors can be seen in what we do
every day in either the human or non-human animal world. Here are some suggestions:
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Is this limited to predator-prey interactions?
Mate choice and behaviour in humans and non-humans
The success or failure of a product being sold.
Can culture evolve?
Eat Prey Live Practical on Natural Selection
Summary: The goal of Eat Prey Live is for students to learn how natural
selection functions via differential replication, and to get students thinking
about the factors that can affect the strength of natural selection.
Introduction
In this practical, you will be using the game Eat, Prey, Live a free mobile game. Ask your instructor
what size of group you should be in and then one of the members of your group (the one with the
largest screen size) should download the game from iTunes or the Google Play Store. If you can’t
find the game, search for ‘arludo’.
Once downloaded, follow the instructions to log in and give the game a try by selecting the basic
features (outlined in white in Figure 1 below).
Figure 1: the population setup screen
Once you complete the first attempt at the game, have a chat with your group members about
what happened and why you think it happened.
Start the game again and take a look at the other values that you can choose and in discussion
with your group members, answer the questions below.
1. How do you think whether traits are allowed to mutate would affect how the populations
change over time?
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2. What affect do you think the population size should have on the effect that predation (your
tapping) has on the traits in the population?
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3. The third choice determines how the traits (speed and agility) are correlated. ‘Speed only’
means that all individuals have the same agility, ‘High Correlation’ means that the faster the
dots are, the less agile they are (and vice versa), and ‘Weak Correlation’ means that faster
dots become less agile, but that agility changes more slowly with every increase in speed.
How do you think the correlation will affect how traits change over time?
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4. ‘Is there a cost’ determines whether hunting dots costs you energy. This means that if you
miss a dot, you will lose energy and come closer to death. As a result, you may not be able to
reach the end of all 10 levels.
How do you think this will affect your hunting behaviour, and therefore, how selection
functions?
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Experimental Design
This is where you will discuss the methods and outcome of the experiment that your group will
run. This should be discussed with the instructor before you begin.
What is the question your group is asking?
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What is your hypothesis?
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What is the methodology that you will use to test this hypothesis?
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What was your result at the end of your experiment? Was it what you expected? Why or why not?
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