Hominin brain evolution, 1925–2011: an emerging overview

Since Raymond Dart named Australopithecus africanus in 1925, palaeoanthropology has been advanced by the discovery of numerous additional australopithecine and other fossil hominins, as well as applications of medical imaging technology for reconstructing and measuring their remains. Although improved dates for some fossils and a better understanding of their developmental trajectories have helped to modify some earlier beliefs about hominin evolution, the now much-enlarged fossil record of South African australopithecines is of key importance for understanding human evolution. This chapter details how the accumulated advances in palaeoanthropology, in general, and the South African record of endocasts , in particular, impact on our understanding of the nature and timing of hominin brain evolution . Three-dimensional computed tomography (3D-CT) of certain South African australopithecines has led to new reconstructions in the form of virtual endocasts as well as revised cranial capacity estimates that impact the overview of the tempo and mode of hominin brain evolution during the Plio-Pleistocene. The recent discovery and reaction to Homo floresiensis is discussed and compared with the earlier reception of Taung’s discovery by scientists and the public. The endocasts of Taung and LB1 are briefly reviewed within the context of the ongoing debate about the respective evolutionary roles of brain size and neurological reorganisation during human evolution.