I asked a quantitative question ... you gave a qualitative answer.
This is how it works, DNA is in the three diminsional form that was made so famous by Watson, Crick and company. In the nucleous of Eukayrotes it is unzipped by enzymes. The strands as they are unzipped are sent to the ribosome that translates them into proteins. The proteins are the building blocks of the new cells.
I know that, including the RNA you seem to have left out

the "biological side" that I don't know too much about are things like mutation and fixation rates, divergence rates, etc.
What we have with this paper is a nearly unsolvable problem, what happens when the genetic code is altered? Most of the time nothing happens but there are transposable elements, no one is really denying this. Some genes are more conserved and this is very important to realize. The genes effecting the brain are highly conserved, changes there can be utterly devastating. They result in things like mental retardation, Alzehiemers and brain tumors. The question for evolutionary biology is how beneficial effects are derived from changes at an amino acid sequence level.
Can you pass me some research on the brain genetics you're mentioning? It seems interesting and off the top of my head it seems like you're describing an "attractor" within the phase-space of possible genomes. Think of the set of all possible genomes as a flat piece of rubber. I take the rubber and stretch it downwards in certain places and upwards in others, to get an uneven surface with peaks and valleys. The peaks would represent deleterious genomic changes (e.g. trisomy 21) and the valleys would represent beneficial genomic changes (e.g. the nylon bug mutation). If I put a steel ball on the rubber (ignoring the dent made by the ball itself) where will the ball go? Away from hills and into valleys. In the same way the gene pool of a species gravitates to increase the relative proportion of beneficial mutations.
Now, imagine you are the ball. One day you wake up in the middle of a deep hole. You try to push yourself out but you can't overcome the gradient. Therefore should you conclude that since there is no way
out of the hole, there is no way
into the hole, and you must have been dropped there by divine fiat? Obviously not. Everybody knows that it is far easier for a ball to roll *into* a hole than out of.
Similarly, the genes you describe as "conserved" may not count as evidence against evolution. Just because they cannot be mutated away from, does not mean they cannot be mutated into.
[But all this is a knee-jerk reaction to what I think you're trying to express by "conserved". I may be wrong. I'd love to see the formal science you're referring to.]
That is why this paper is so important, they actually looked for the divergance. It took a lot of courage for them to admit the differences, they are extensive. That is the cool thing about science, the evidence cannot lie. Things would have had to change at a dramatic level. We are not 98% ape, in fact, I am not convinced that it is even 90%. Evolution would have had to create differences by some currently unknown process for natural selection to preserve changes on this level.
But what is the
rate? And why does the
rate seem so incredulous? I don't get why you don't get my question. If I told you "I can run 200km" you might think I'm lying - but only if you unconsciously assume that I must have run that 200km in a short period of time.
Is the
rate of divergence really that earth-shattering?