Sorry, Nums, I can't understand your point. At the end of your post you say "evolution, only works from the individul's point of view". And that's right. So, how can you say that the interest of single robots should be to keep their mutation rates at 0, because mutation is in the species' interest?
If evolution works from the individual's point of view, and species evolve, this must be because mutating is in the individual's interest.
View it this way. Many biologists even say that evolution works from the gene point of view, that is mutation is in the interest of the genes, not even the individuals. Suppose you have a robot with n genes, and one of those genes is able to specify the global mutation rates for that robot. That gene should be more likely to spread if it triggers little enough mutations to preserve the dna functionality, but, at the same time, it has to trigger some because this increase its probability to spread in an environment subject to slow changes.
Anyway, I did some experiments with DarwinBots some time ago. I took some kind of rather primitive robot (like C. Circumgirans, or so) and cloned it (loaded it two times in the same simulation), creating two teams. One of them had a zero mutation rate, and the other one a low mutation rate, greater than zero. Then a ran a few simulations, and - surprise!- usually the team with a non-zero mutation rate won the sim. Well, now you have teams and auto reloading of sims with stats, so you can make some more accurate study about it. Who wants to try?
Bye, C.