It's stunning, sometimes, how poorly written the press stories are. Do these writers ever read the original article or talk to the researchers?
When human and chimp DNA is compared and average rates for genetic differences are calculated, a genetic evolutionary speed is inferred. But the cognitive difference between humans and chimps is greater than this genetic difference would imply. It has long been hypothesized that this difference is due to differential gene expression. That is, the difference is an amplification in the downstream transcription and translation of small coding differences seen between humans and chimps. This is the first study which demonstrates this difference in activity of genes in the brain. There is very little, if any difference in expression levels of other systems like liver and blood.
If no difference in expression levels had been found in this study, as Edwin McConkey says: "...we should all have to take a course in metaphysics, and religious fundamentalists would be dancing in the streets."
Oh come on now, the argument would be made that this is evidence of the common ancestry of chimp and man and is conclusive evidence of Darwinian evolution.
"They found five times as many changes in gene expression -- actual activity by the genes -- in the human brain than would be predicted by evolution.
"If two species have been apart for 5 million years, you expect a certain amount of differences," Varki said. But there are many more differences in the human brain than expected. "Whereas if you look at liver and blood, you don't see that," Varki added
There are direct quotations. Apparently the writer has has at least listened to the researchers.
I don't see how the text of the article is much different than your statements that "when human and chimp DNA is compared and average rates for genetic differences are calculated, a genetic evolutionary speed is inferred. But the cognitive difference between humans and chimps is greater than this genetic difference would imply." How is that much different than saying that they found many more differences in the human brain than they expected? And why did they expect certain results? They were expecting different results because they were inferring a "genetic evolutionary speed", as you correctly point out.
Cordially,