The BiomorphBounce Applet

You're not loading applets -- maybe your browser doesn't support them,or maybe you don't trust me :-). Either way, you're welcome to the source code.

A non-technical description of BiomorphBounce

This applet draws biomorphs, plausibly lifelike forms invented by the brilliant evolutionary biologist Richard Dawkins and first presented to the world in his book The Blind Watchmaker. (Giving credit where due, my biomorph-drawing code is derived from code written by Shane McKee.) In this exhibit, the biomorph's DNA changes with time, and the result is continually updated in the applet's window. I believe that most computers can easily show 50-100 of these per second, but I think update rates of 10-25 look nicer.

To get an idea of how the biomorph is changing, imagine that there is a knob associated with each of the eight genes comprising the biomorph's genome. Each knob slides smoothly and independently, and the biomorph is redrawn after each change. You can see that the knobs move smoothly because each biomorph is very much like the previous one -- that is, each individual change is minor. Each knob moves in a set direction at a constant speed until it reaches its maximum (or minimum) value, then it bounces back the other way. This is why the biomorphs are oriented up, then down, then up again -- one of the genes controls upness or downness, and its knob is bouncing back and forth along with the others. (When I get some time, you won't have to imagine this any more -- I'll actually have the applet show you!)

BiomorphBounce illustrates two points. First, it shows what a wide variety of forms is possible even with a very limited genome -- you may see forms that look like insects, trees, letters of the alphabet, and so on. Eight of the genes can take on eleven different states, and another can take on five different states -- a total of 1,071,794,405 different biomorphs! With over a billion different biomorphs, you're not likely ever to see the same one twice.

Second, the exhibit demonstrates how an accumulation of changes can turn one form into a quite different form, even when each individual change is very small.

You're welcome to the source code.