You can insert such a thing into the bots' DNA, but it will probably quickly evolve to break it. Evolution is really good at breaking certain parts of the DNA, it's among the first things it "tries".
Sure, it's only logical. For further evolution the bots have to break any restrictions. More or less the bots are asexual so one bot's evolution has to occur at the expense of all others. One bot will break it first and then replace/destroy the others that have the restrictive genes. The same thing is commonly seen with Canni's.
I normally just use restricive or specific genes with the knowledge that evolution will come along and break them in sucessive generations. Normally something like:
'Last Gene
cond
*.robage 10000 >
start
.delgene inc
stop
works best. I've deliberatly tried restricting mutations with a dnalen restriction, and evolution still wins out. :)
They really like using the new flip mutation to do break them for some reason. I think it makes it easier, since it is more likely to affect more dna.
I don't know if we should call such behavior cancerous, technically the vegs are just playing the system. Evolution is "telling" them that the cost of attempting to reproduce is les than the penalties.
Basically the vegs are restricted by veggie population size and total veggie nrg. Since they can expand their total population size by continually reproducing it's better if they do. Increasing the total size decreases the chance of any specific vegie from being eaten. If they're being eaten this depletes total nrg and is again a good time to try and reproduce.