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Natural Selection
In this simulation you will investigate populations of birds living on an island. You will begin by selecting three birds that will represent phenotypes for several traits in one population that lives in the southwest portion of the island. You will explore how this population changes over time in the southwest. Then you will explore how the population evolves over long time periods in various environments on other areas on the island.
Choose plumage, body size, and beak traits for each bird.
  • plumage light green
  • plumage light brown
  • plumage yellow
Body Size
  • body size. medium small
  • body size. medium
  • body size. medium large
  • medium short
  • medium
  • medium long
  • slight
  • curved
  • medium
Mountain Range
This part of the simulation represents 500,000 years. A bird
population exists in the southwestern portion of the island.
During this time, mutations may change the fitness of some
birds and their descendents in the environment.

Birds with traits that enhance their fitness are
more likely to survive and reproduce.
In the southwest, your birds will find: seeds and edible insects for
food, no predators, and light green foliage.

You have selected three phenotypes for birds that are representative
of the large range of phenotypes that could be present in the
population of birds. Of those that you selected, how fit do
you think each phenotype is in the current
environment? Record your ideas on the Student Sheet.
You will observe how phenotypes and number of birds
change in the three populations as thousands of years pass.

When prompted to do so, discuss with your group your
ideas and record them on the Student Sheet.
Predator Icon: If present, the size represents the
threat posed by available predators.
Population count (pink means it's declining)
Resource Icons: The size represents the ability
of this bird phenotype to utilize the resource, if
Foliage color in the environment
Years Have Passed
Bird 1
Bird 2
Bird 3
After 500,000 Years
With your group, discuss how the bird populations changed over the course of 500,000 years. Were your ideas about the fitness of each phenotype you selected correct? Explain why or why not. Record your ideas on your Student Sheet. Compare how your bird populations changed with the bird populations of another group of students.
Record the similarities and differences you notice.
Mountain Range

A hurricane has hit the island and some of your birds have been blown to three new areas!

Each area has a unique environment. Work with your group to create the Northeast environment. The other two environments will be created for you.

The simulation in the next part will stop every 50,000 years beginning at 500,000 years and ending at 1,000,000 years. This will give you a snapshot of the major changes in the bird populations and the environment during that time. While there are many other changes that could be occuring in the environment and the bird populations, they are not shown in this simulation.

Each time the simulation stops
  • Observe and record on the Student Sheet the changes that have occurred in you assigned area.
Then click "Next" and
  • Discuss with your group the changes that occurred and the reasons for the changes.
1. Northeast
2. Northwest
3. Southeast
Discuss with your group which birds are more likely to be most fit and least fit in each new environment. Record your ideas on the Student Sheet and explain your reasoning.
Select the first environment

For FOOD, you may only spend 3 points:
Selecting some costs 1 point
Selecting plentiful cost 2points

When you have selected all the environment variables, click CONTINUE.

The NORTHWEST and SOUTHEAST environments will be created automatically.
500,000 Years Have Passed
After a million years of natural selection how much different are the
most recent birds from the original birds?
Original Birds
After 500,000 years ...
After 1,000,000 years ...
Restore simulation from previous save point
Select a restore point:
You save the state of your simulation and restore it within 30 days.

Please enter a description to identify your save point (E.g. John Smith)
All Populations Extinct
All phenotypes have gone extinct. Please restart the activity and select more varied phenotype characteristics.