A very fruitful collaboration between anthropologists from Great Britain, Germany and Austria has produced an extensive research supporting the existence of hand movements similar to those of the modern man among the fossil species of Australopiths, who lived 3-2 million years ago.
Evolution shows that the form of the hand has changed over time in various phases, depending on the necessities of the species, from the time of the arboreal locomotion to the manufacturing of stone tools. These transitions have caused the hand to change and be able to use focused precision. They also gave it the power to grip or squeeze different objects, like hammers. However, anthropologists were not sure of the time when the crafty and locomotive transformations took place.
Dr. Matthew Skinner and Dr. Tracy Kivell found a new way of dating the fossil species based on the use of their hands and by studying the trabeculae–the internal structure of the bone. How were the bones relevant? Their internal structure changes and alters very quickly during a lifetime and it can tell the story of human behavior which imprints in the bones.
Basically, what researchers thought of doing was comparing the trabeculae of both human and chimpanzee hands, and studying the differences. The results showed that humans have the unique skill of gripping objects between their thumbs and fingers, whereas the chimpanzees were unable to hold objects in a human-like manner. This human skill was used as criteria for studying fossil species, and only Neanderthals showed the same “symptoms” of a non-arboreal lifestyle and stone tool-making.
However, this new study discovered that the bone-pattern of a previous species, the Australopithecus africanus, is similar with the one found in the bones of the thumb and the metacarpals consistent with tool-making species.
The current study is compatible with previous evidence found in different archeological sites about the tool use of Australopiths. Furthermore, it offers new skeletal evidence which proves that our ancestors used their hand for tool-making even earlier than anthropologists thought they did.
Image Source: Science Mag