A single gene change that boosts the amount of a certain protein in early brain cells causes mice to develop abnormally large brains, Reuters Health reports. Normal mice have smooth, flat brains. But tinker with the gene in question and suddenly the little furballs develop brains so big they fold in on themselves, forming the wrinkles, ridges and crevices found also in the human brain. Study author Dr. Anjen Chenn of Brigham and Women’s Hospital and Harvard University in Boston said the finding might help researchers understand how humans came to develop brains so much bigger than those of other mammals. Whether or not more size means more smarts is uncertain, Chenn said. “It is quite an interesting question … and that’s something we want to look at in the future.”