Human evolution species were indeed responsible for most of the Oldowan tools found. They argue that when most of the Oldowan tools were found in association with human fossils, "Homo" was always present, but "Paranthropus" was not. In 1994, Randall Susman used the anatomy of opposable thumbs as the basis for his argument that both the "Homo" and "Paranthropus" species were toolmakers. He compared bones and muscles of human and chimpanzee thumbs, finding that humans have 3 muscles which are lacking in chimpanzees. Humans also have thicker metacarpals with broader heads, allowing more precise grasping than the chimpanzee hand can perform. Susman
Effect of spaceflight on the human body examined will become important. Overall, there is little data on the manifold effects of living in space, and this makes attempts toward mitigating the risks during a lengthy space habitation difficult. Test beds such as the ISS are currently being utilized to research some of these risks. The environment of space is still largely unknown, and there will likely be as-yet-unknown hazards. Meanwhile, future technologies such as artificial gravity and more complex bioregenerative life support systems may someday be capable of mitigating some risks. Effect of spaceflight on the human body Venturing into the environment of space can have negative