“When tested out in mice, researchers found this “error” caused the rodents’ brain cells to move into place faster and enabled more connections between brain cells.” What could possibly go wrong? (and pass some of that my way!)

Did a Copying Mistake Make Humans So Smart? : Discovery News Mistakes made during cell division long ago may have lead to the sophistication of the modern human brain. http://news.discovery.com/human/ancient-human-brain-neanderthal-120506.html