No. [edit: Upon further reflection, I may have misunderstood you. If you simply mean that humans and bacteria have a lot of DNA in common, then I of course agree.]
> there is the possibility that we're already nearly evolutionarily optimal for this universe.
So you think humans are the general solution for the global^Wuniversal optimization problem? Unlikely. Even if we assume that humanity is somehow optimal right now, will this be true in even 100,000 years? A global temperature change of a few degrees or a change in the concentration of oxygen in the atmosphere could render us utterly non-optimal.
By way of example, consider that 500 million years ago there was considerably more oxygen in the atmosphere than now. This meant that insects could grow much larger than they are today withought needing to invest resources in lungs to support their body mass (insects lack specialized circulatory organs, generally). But fast forward today and giant insects are a manifestly suboptimal solution. I'm personnally grateful.
I was referring to this: http://www.sciam.com/article.cfm?id=strange-but-true-humans-...
> So you think humans are the general solution for the global^Wuniversal optimization problem?
It's not that we're physically optimal, but that we're good enough to be able to manipulate heat to an extent that makes metallurgy possible, which allows us to non-trivially optimize our environment to ourselves.
Just because web source code looked a lot different fifteen years ago doesn't mean it'll change considerably fifteen years from now. Mutation can be beneficial, but it can also carry the unfortunate cost of breaking compatibility.