Strikingly, thin bones were always present in both ears, suggesting that the weakness may be a birth defect or
inherited trait rather than an infection, such as meningitis or syphilis, which might affect the ears differently.
Rather than
inheriting big brains from a common ancestor, Neandertals and modern humans each developed that
trait on their own, perhaps favored by changes in climate, environment, or tool use experienced separately by the two species «more than half a million years of separate evolution,» writes Jean - Jacques Hublin, a paleoanthropologist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, in a commentary in Science.