Article on the Avida genetic programming system
Avida is an open-source software laboratory, which uses evolving computer programs to study evolution. Here’s an interesting article called Testing Darwin from Discover magazine, which is about interviews with the Digital Evolution Laboratory at Michigan State University (which develops Avida).
One of the most interesting parts is at the end, where researcher Ofria describes how the organisms even evolved ways to avoid being selectively killed by the experimentors.
Ofria had wanted to see what would happen if he killed off any organism with a beneficial mutation. So he ran a program which tested each organism for beneficial-ness. However, the organisms evolved to recognize regularities in the test environment, and to “play dead” when they were being tested, thereby avoiding being weeded out.