Choice of the parameters that can and can not evolve can be controversial as well as details of the model of the world. However, it is not just a problem of selecting solutions that I or someone else like. Many solutions leads to worlds that are always (or almost always) ecologically unstable. After three months of playing with the model and its parameters I decided to make the program available to others, as it will probably never reach really mature state. Right now I am trying to put as many parameters into animals so that they can evolve. This approach always leads to problems - bitozoa are complicated enough to be not able to survive if all parameters have random values, yet some must survive for simulation to continue. If the world at the beginning is full of food which makes initial survivability easier simulation soon slows to a crawl as the world becomes full of animals. It is not easy to find the balance between all opposing requirements, but I am working on it.
Here is an example of a possible problem. At some point I allowed bitozoa to "select" best numbers for the stamina breed level and for the inherited stamina. This proved to be a disastrous solution. Soon the world was full of large carnivores that were unable to breed (breed level was almost equal to stamina level for asexual reproduction). Evolution was shortsighted - it has found that optimal solution for the moment will be to not use sexual reproduction and to slow reproduction process. In effect whole species became extinct some time later, when its prey evolved so that it was able to avoid most of the attacks.
Bitozoa are sponsored by dysleksja, ChemBuddy chemical calculators, pH meter, titration site.