Bead Bug Activity
Key Vocabulary
Inherited Characteristic: a trait passed down from a parent to an offspring
Adaptation: an inherited trait that offers an advantage to a species (to survive and reproduce)
Evolution: a change in an inherited trait over time within a species
Species: organisms that can mate and produce fertile offspring
Population: two or more species with variations in their inherited traits that live in the same geographical area
General Information
In this lab activity you will observe of a population of bead bugs undergoing evolution. Available to you is a
species of insect called a bead bug (represented by the beads) and an environment in which the bead bugs live
(forest-like paper). Here are some important facts:
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Bead bugs live in the leaves and branches of the forest, and feed on the leaves.
Bead bugs only die by being eaten by birds (predators)
Each year birds each 50 percent of the bead bugs
Each year the bead bugs reproduce
During reproduction, bead bugs experience a variation in their color
Procedures
1. You will start with 20 bead bugs: 10 yellow and 10 reddish-brown.
2. Choose one member to spread the beads randomly in the environment.
3. Choose a member to act like a bird. Acting like a bird, fly over the area and choose the easiest bead
bugs to see and catch. One at a time, select a total of 10 bead bugs.
4. After feeding, count the number of each color left in the forest, and record your data.
5. Simulate reproduction, and add an equal number of beads for each color. For example, if 7 yellow
beads are left then add 7. Record your data. You should have a total number of 20 bead bugs
6. Simulate a variance in reproduction, remove one yellow and one reddish-brown bead bug, and replace
them with a light green bead bug. Record your data. You should still have 20 bead bugs.
7. Plot your data on the chart using columns to represent each color bead bug. For example:
6
4
Series 1
2
Series 2
0
Series 3
Category 1 Category 2 Category 3 Category 4
Repeat the above steps for each generation.
Name(s)______________________________________________________ Date_______________________
Bead Bug Activity (Evolution)
Generation
1
Before Feeding
After Feeding
After Reproducing
After Variation
2
Before Feeding
After Feeding
After Reproducing
After Variation
3
Before Feeding
After Feeding
After Reproducing
After Variation
4
Before Feeding
After Feeding
After Reproducing
After Variation
# of Yellow Bead
Bugs
# of Reddish Bead
Bugs
# of Light Green Bead
Bugs
# of Bead Bugs
10
10
0
20
10
20
20
20
10
20
20
20
10
20
20
20
10
20
20
20
18
16
14
12
Yellow Bead Bugs
10
Reddish Brown Bead Bugs
8
Light Green Bead Bugs
6
4
2
0
Generation 1
Generation2
Generation 3
Generation 4