So, an increase in fitness is not necessarily an increase in complexity. Is that what you are saying? I always thought the fundamental assertion of evoltuion is that matter has demonstrated, by and large, a progession from the simple to the more complex. Of course, if it is a theory to which all the evidence can be shoe-horned, one would expect there to be ample cases of the reverse.
The fact is, in every case where matter is organized an argument against unguided, unpurposeful, undesigned, unintelligent cause is made. It would be a better argument for evolution if the general direction of matter were toward dissemblance, but that does not seem to be the case at least in our biosphere.
"So, an increase in fitness is not necessarily an increase in complexity. Is that what you are saying?"
The "complexity" bothers me, but in general, yes. Each thing is tested for fitness. If it fails, it dies. If it passes, that's good. There are a lot of very fit, much less "complex" things out there that are doing quite well.