Darwin’s Theory of Evolution
Sri Lanka Elephants Experiment
Background Information:
In this experiment, you will simulate Darwin’s Theory of Evolution using different colored beans
to represent elephants that live in Sri Lanka. Some elephants on the island of Sri Lanka are
born with tusks and others are born without tusks. Asian elephants on the island of Sri Lanka
are hunted or “poached” for the ivory in their tusks. The ivory is used in jewelry and other
trinkets around the world and is extremely valuable to poachers.
Materials:
Paper bag labeled “Sri Lanka” with 20 red beans and 20 white beans
15 red beans in a bag labeled “Babies”
An empty bag labeled “Death”
Hypothesis/Prediction:
Which trait do you think will be the better adaptation to have? Why? (To have tusks or to not
have tusks)
Procedure:
In this simulation, you and your team will represent the forest and the poachers.
The person with the bag labeled “Sri Lanka” represents the forest.
The rest of the team will represent the poachers.
Round 1: A poacher should choose a bean from the Sri Lanka bag without peeking.
If the bean is RED: This elephant is tuskless and the poacher lets it stay in the forest. Put
this bean back and add two more red beans to represent the babies this elephant will have.
If the bean is WHITE: This elephant has tusks. The poacher kills the elephant. Place this bean
in the “death” bag. Do not add any additional beans to the Sri Lanka bag.
Repeat the steps for at least 10 rounds.
AFTER all ten rounds, count the number of red beans and the number of white beans left on the
island (in the Sri Lanka bag). Share your results with the class
START
Red Beans
20
White Beans
20
After 10 Rounds
Class Data
Conclusions:
Answer the following questions based on the experiment we did with the beans.
1. What has happened to the population of tuskless elephants?
2. What has happened to the population of elephants with tusks?
3. What is happening to the tusk trait?
4. Over time, what do you predict will happen to this trait?
Fill in the chart below using the beans in the bags to represent the elephants. Think about the
sea turtle example we went through in our notes to help you.
Beans
Overproduction
Many beans in the bag
Variation
Some red, some white
Struggle to
Survive
Trying not to end up in
the “death” bag
Survival of the
Fittest
Red beans go back in the
bag and white beans are
put in the death bag
Inheritance of
Traits
If a red bean goes back in
the bag, two more red
beans are also added
Elephants