The hand structure of pre-humans may have allowed them to use tools much earlier than previously believed. Scientists analyzed fossil hand bones of the Australopithecus africanus who lived about 3.2 million years ago in what is now South Africa. The hand bone structure revealed that ancient humans were able to fully grasp and use tools. In a study published in the journal Science, anthropologists said that Australopithecus could use its hands very much like modern humans.
Australopithecus looked like apes, but had human characteristics
Until now, scientists believed that Australopithecus africanus did not build tools, but the latest evidence suggests otherwise. The first traditional evidence of tools dates back to 2.6 million years, built by a species called Homo habilis. Australopithecus had an ape-like face and long arms, and walked upright on two feet. They descended from the trees and gained hand dexterity.
One of the hallmarks of humankind is our opposable thumb and the way it allows for a strong and precise grip. Scientists led by Matthew Skinner of the University of Kent studied trabeculae, the internal spongy structure of bones. Trabeculae reveal how the hand bones were used when the individuals were still alive. Chimpanzees can’t mimic the way we can grip forcefully using thumb and fingers because their trabecular bones look very different.
Australopithecus had human-like trabecular pattern
In this regard, Neanderthal fossils closely resemble modern human hands. Neanderthals had the ability to use tools and make cave paintings. Skinner said Australopithecus too had human-like trabecular pattern in the bones of the palm and thumb. It forces us to revisit how we think about the ways pre-humans made the living. It could be a crucial evidence of our heavy reliance on tools millions of years ago.
Researchers focused on a small portion of the base of the thumb bone underneath the muscle. They found a wear pattern similar to that present in humans from frequent activity. This pattern was absent in chimpanzees, our closest genetic cousins. Our last common ancestor with chimpanzees lived about 7 million years ago.
