The Center for Connected Learning and Computer-Based Modeling

the Center for Connected Learning (CCL)
and Computer-Based Modeling

affiliated with the departments of Learning Sciences and Computer Science
and the Northwestern Institute on Complex Systems at Northwestern University

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BugHunt -- Simulated Evolution
A Project Sponsored by OBONU 2009

How to Play | How it Works | Mechanisms | Evidence of Evolution | Play

What is the Evidence of Evolution in BugHunt?

The Camouflage Metric Graph

As you play bug hunt you will see a graph titled Camouflage % vs. # Caught. This graph shows how well camouflaged the population of bugs is. It measures how close the rgb value of each bug is to the rgb values of the pixels in the environment adjacent to it. As this value increases the bug population is becoming better camouflaged. If the value drops then it is becoming more poorly camouflaged. This value is always scaled to start at 0 for any environment.

If you and the other players were to close your eyes and randomly click around the screen you would find that the camouflage % would randomly fluctuate up and down and may drift in a direction (up or down), but repeated results would not show a clear and consistent trend upward or downward. This effect is a form of genetic drift.

But, when you and other players open your eyes and intentionally compete against each other, the camouflage % value will trend upward until toward the end of the competition when it eventually levels off (though it may continue to fluctuate). When the camouflage % shows this, where no further increase appears to occur, the bugs in the population are usually very difficult to find (though not impossible).

Snapshots in Time: Images of the Population Before and After the Competition

In addition to observing the graph you can study the starting and ending population of bugs from various competitions. For example, you can observe the following:

A typical starting population of
randomly colored bugs: What a typical population looks like
at the end of competition:

What the starting population of bugs looks like
in its environment at the start of the competition: What the population of bugs looks like in its
environment at the end of the competition:

Notice the coloring and placement of the bugs. The results of every competition are very similar. Bugs are colored similar to their surrounding at the end of the competition.

In different environments the coloring is different. In different competitions millions of variations can emerge in the population. But study any one of these outcomes and you will see evidence of camouflaging evolving in each BugHunt competition.

Here are some of the environments that you can play in and examine the outcomes:

PoppyField MarsSurface RainForest Glacier Seashore NUbreakwall NUevergreen NUpondshore

Or view top scores from the previous competitions.

How can I contribute a new environmental background to be included in the BugHunt competitions?

We encourage players to contribute photographs to be used as new environments for the bug population to evolve in. To contribute an image to be used as a new environment, simply send a jpeg file that is 486 by 486 pixels along with a short description of where and when the photo was taken to:
ccl-obonu@ccl.northwestern.edu

Images will be reviewed and added each week to BugHunt. So come back often to play BugHunt in these newly added environments.