The most concrete evidence for the evolution of man consists of the fossil bones of man-like creatures who proceeded us during the past. From interpretations of these fossil bones, ideas can be formulated as to how our ancestors looked, stood, walked, used their hands and, in broad terms, behaved. The number of specimens of fossil men that are in our possession is at once both large and small. As representatives of the populations of ancient man that must have existed, they form a small sample; but some hundreds of skulls and skeletons and several thousands of teeth are known. This is the raw material of paleo-anthropology.