the arms from the task of walking and made the hands available for tasks such as gathering food. At some point the bipedal primates developed handedness, giving them the ability to pick up sticks, bones and stones and use them as weapons, or as tools for tasks such as killing smaller animals, cracking nuts, or cutting up carcasses. In other words, these primates developed the use of primitive technology. Bipedal tool-using primates from the subtribe Hominina date back to as far as about 5 to 7 million years ago, such as one of the earliest species, Sahelanthropus tchadensis. From about 5 million years ago, the hominin brain began to develop rapidly in both size and differentiation of function. There has been a gradual increase in brain volume as humans progressed along the timeline of evolution (see Homininae), starting from about 600 cm3 in Homo habilis up to 1500 cm3 in Homo neanderthalensis. Thus, in general there's a correlation between brain volume and intelligence. However, modern Homo sapiens have a brain volume slightly smaller (1250 cm3) than neanderthals, and the Flores hominids (Homo floresiensis), nicknamed hobbits, had a cranial capacity of about 380 cm3 (considered small for a chimpanzee) about a third of that of Homo erectus. It is proposed that they evolved from H. erectus as a case of insular dwarfism. With their three times smaller brain the Flores hominids apparently used fire and made tools as sophisticated as those of their ancestor H. erectus. Homo Roughly 2.4 million years ago Homo habilis had appeared in East Africa: the first known human species, and the first known to make stone tools, yet the disputed findings of signs of tool use from even earlier ages and from the same vicinity as multiple Australopithecus fossils may put to question how much more intelligent than its predecessors H. habilis was. The use of tools conferred a crucial evolutionary advantage, and required a larger and more sophisticated brain to co-ordinate the fine hand movements required for this task. Our knowledge of the complexity of behaviour of Homo habilis is not limited to stone culture, they also had habitual therapeutic use of toothpicks. A larger brain requires a larger skull, and thus is accompanied by other morphological and biological evolutionary changes. One such change required for the female to have a wider birth canal for the newborn's larger skull to pass through. The solution to