In this line of thinking has anyone ever considered that there may be an average general rate of evolution based on the level of complexity of the specie evolving
Molecular biology has considered this. I believe it has been confirmed that there is a different rate of evolution for vertebrates than invertebrates.
Environmental factors are an obvious push but does a less complex organism have a better chance of adapting than a more complex one?
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.
Is biological complexity itself an advantage or disadvantage?
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.
Its just that once single-celled organisms began cooperating with one another in a 'complex' manner they had such a short term advantage over their uncooperative rivals that they were able to reproduce more often/more easily/etc.
As Einstein is credited with saying:
quote:
"I don't know what weapons World War Three will be fought with, but World War four will be fought with sticks and stones."
Sticks and stones are not complex, but they have an advantage in that they are simpler and everyone can use them. However, the moment arrives when someone sharpens his stick and then someone else sticks a pointy rock on the end, later someone shrinks the stick and fires from a bow...you know the rest. When the competition gets more advanced you escalate or die. Its tragically doomed to failure, but there you go.