Brain evolution in early Homo Human brains are larger than and structurally different from the brains of the great apes. Ponce de León et al. explored the timing of the origins of the structurally modern human brain (see the Perspective by Beaudet). By comparing endocasts, representations of the inner surface of fossil brain cases, from early Homo from Africa, Georgia, and Southeast Asia, they show that these structural innovations emerged later than the first dispersal of the genus from Africa, and were probably in place by 1.7 to 1.5 million years ago. The modern humanlike brain organization emerged in cerebral regions thought to be related to toolmaking, social cognition, and language. Their findings suggest that brain reorganization was not a prerequisite for dispersals from Africa, and that there might have been more than one long-range dispersal of early Homo . Science , this issue p. 165 ; see also p. 124