It’s known to all that humans evolve or else we could not have become the most productive and intelligent species on the Earth. It took millions of years for humans to reach the stage where we are in today and most interestingly, the process of evolution continues as we progress ahead. The most important milestone in human evolution is the stage that occurred almost 6 million years ago when humans were able to walk upright on short legs. Another aspect that needs special mention is the sign of a significant social shift that became evident from the same size of the canine tooth for males and females.
Humans walking upright – Unraveling the cause
According to anthropologists, almost 12 million years ago the Great Ape demonstrated the first sign of bipedalism which means moving upright on two rear limbs or legs. Not only could they walk on two legs but also hang from trees. Walking upright is the most defining characteristic of modern humans or Hominis that they inherited from their ancestors. However, the most intriguing question that anthropologists seek answers to is why humans walk upright. It took many million years for bipedalism to become an established practice among humans that differentiated them distinctly from their ancestors, especially the Ground Ape. So, how was the people’s movement in the ancient past? Anthropologists depend on the shape of a creature’s bones and its setting to understand the kind of body movement of the creature when it was alive.
The discovery of Ardi
In 1994, scientists for the first time discovered the fossils of an unknown Hominin in Ethiopia. It was the remains of Ardipethecus ramicus, a female individual, later nicknamed Ardi. In the following 10 years, scientists found more than a hundred fossils belonging to Ardi’s species that were between 4.2 million to 4.4 million years old. By examining the collection of bones, scientists identified certain characteristics that pointed to bipedalism. For example, the structure of the foot bore hints about facilitating the toe push-off, the kind of movement that humans demonstrate today. Such foot structure is absent in four-legged apes.
Moreover, the shape, structure, and position of the pelvic bones and their alignment and fit with the leg bone were suggestive of upright walking. Perhaps, Ardi’s way of walking was different from the way we walk today. But, it deeply resembles the distinct traits of bipedalism, the normal style of movement typically characterized by the fossils that existed 4.4 million years ago.
What prompted Hominins to walk upright?
It took millions of years before humans could comfortably walk upright because the process of evolution is gradual and it took almost 4.4 million years to complete the process, but much before the advent of tool-making. However, what was the cause of Hominis walking upright? The possible reasons are that it helped them run faster, and made it easy for them to see predators from a distance. Another possible reason could be that with time there were fewer trees to climb to protect themselves from enemies.
Regardless of the reason for walking erect, the upright position freed the hands and made it easy to use tools which was another milestone in human evolution.