Genes Expressed in Brain Evolving at a Medium Pace

Even mice brains evolve faster than human brains, and our complexity may be the culprit

The human brain is not a chimp brain. Sure, somewhere between five million and eight million years ago, before the two species diverged, there was no difference. But at this point, despite our bodies weighing only 20 percent more than those of chimps, the human brain weighs 250 percent more and contains 50 percent more neurons. Eight million years notwithstanding, that would seem to be a sign of rapid change.

But a team of researchers from the University of Chicago, as well as from institutes in Taiwan and Japan, says not so fast, at least with regards to the speed at which the human mind has evolved since its split with the chimpanzee.