What really matters is diversity. If there are a lot of different alleles in the population, the more chance the population has to adapt to changing environment. Sexual reproduction spreads genes around significantly, so sexual reproduction might be a characterstic for a fast evolving organism.
I am asuming alleles evolve. New alleles must emerge correct? If so what effects the rate of devergence. What effects which new ones will emerge and thier purpose? There must be some governing factor or life would develope into the equivalent of an abstract art painting no?
So weather or not a species will have adaptability at this time appears to be a crap shoot. Or do species possess as a whole, all the genetic blueprints they will ever have and it appears they become active or dormant depending on stimulation?
I have looked on the web from time to time but seldom see direct questions like this addressed. If I do run across something I might not recognise it for what it is.
Biological complexity isn't really a characteristic unfortunately, as you have anticipated. The merit a set of genes has for building a machine slightly more advanced than its rivals is that gene may be able to take advantage of a niche that is unoccupied, which means those genes are free to replicate with no competition (short term). We have to look at these things as short term goals...to reproduce successfully. So, in the short term, complexity is advantageous. However, like any arms race, it may well have been more efficient had the escalation never happened and everything just remained single-celled.
Has anyone hypothesized why life took a general move toward the more complex in the first place? Then one could think of insects and animals as just a macro of single cells. We have membrains and cilia of a fashion and our insides are divided into differnt parts that work together as a whole. So in your line of thinking we are likely a short lived phenomenon in the big biological picture? We are quite young as species go. The anology I have heard before is that if the evolution of life on earth were represented as a calender year. Man would show up during the last second of the last day in the year. Perhaps like the exotic elememt that exhibits amazing properties but decays most rapidly. Are we but a brain fart in the biological bowel movement? lol