In every sim I've run or read about (except internet mode), eventually de-evolution has overcome evolution as has happened with your animal minimalis.
I'm not so sure if this is a proper way of phrasing what happened. Evolution is not survival of the fittest, it is survival of the least unfit. A strain can survive negative mutations if they are offset by positive ones. A strain doesn't have to be optimal, better is enough.
De-evolution would imply that the 7M cycle strain would outcompete the 10 m cycle strain in a death match. I haven't tried
Solutions to this could be increasing population size to thousands, decreasing mutation probabilities (to something like 1/8 or less of default settings, probably) or provide strong enough evolutionary pressure by competition or shepherd bots or some other way.
The animalis population was set at 200 by costX and varied between 150 and 250 max. Mutation settings were at 1. The major random factor hindering ''optimal selection'' was food availability. Algae distribution was not uniform. A strain in a rich part can replace a strain in the poor part. C' est la vie.. On the other hand I have a suspicion (anecdotal observations, not traced back into the code) that at least sometimes reproduction was postponed untill food was available. This would imply adaptation (or selective observation on my part of course )
Sexual reproduction also helps, but in my sims it has been replaced by faster asexual reproduction. It has taken some time though.
This is on my original to do list: death matches between otherwise equal sexual and a-sexual strains. The main problem is they only differ in the way they handle mutations, and a large number of replications is probably needed. I need to figure out how to set up my own little evo league and have a lot of patience..
I'd like to know the results of this.
Will do..
It's quite usual for the evolved strain to be less fit, but more resistant to mutations. See survival of the flattest.
To me fitness is defined as the ability to create offspring that survives, not fast reproduction. Allthough I haden't recognised it as a selection criterion, resiliance in the face of mutations is a part of what I would consider fit.