Australopithecus used their hands to climb and perform delicate manipulations. This was shown by an analysis of the found bones of the ancient human ancestors. Research results are published in the journal Nature Ecology & Evolution.
Australopithecus, although they are called the “transitional” human ancestors, had a number of evolutionary advantages, which are traditionally attributed to the early Homo. In fact, a number of transformations of the body and, as a consequence, a lifestyle occurred before the appearance of Homo. So, the transition to upright posture occurred in Australopithecus living in Africa. They were the first to not only climb trees but also walk on two legs.
Such a transition actually freed the forelimbs, which Australopithecus cleverly used for instrumental activity. It was previously believed that the first Homo began to engage in rather subtle manipulations that were purely anatomically inaccessible to climbing primates. Studies of the University of Kent led by Professor Tracy Kiwell point to the same transition. True, it turned out that the transition to complex actions occurred earlier.
Scientists conducted an analysis of the structure of bone tissues and joints of the Australopithecus sediba hand, and then compared the data with other Australopithecus A. africanus and A. afarensis, Neanderthals and sapiens.
According to the results of the study, the structure of the bones of the proximal (first) phalanges of the fingers demonstrates the ability of Australopithecus to grab branches while climbing trees. And the structure of the joints of the thumb speaks of the complex manipulations that this human ancestor was able to carry out. In fact, scientists say, Australopithecus had a transitional structure of bones, showing the process of rejection of climbing and the desire for upright posture. As a result, the hands were becoming more and more free for instrumental activity.
“We were amazed to find that Australopithecus sediba had such unusual hands for Australopithecus. Fossils reveal new forms of diverse ways of moving and interacting with the world that our ancestors tried out, ”said Professor Kivell.