Bipedal Locomotion

The capacity for bipedal locomotion has always been considered a defining characteristic of the human species, and it is one of the most important features that paleoanthropologists look for when trying to determine whether an ancient species was part of the human lineage. Recent paleoanthropological work has demonstrated that bipedalism might have occurred much earlier than previously thought, with the recovery of fossil evidence, dated up to 7 Ma, that suggests potential bipedal locomotion in various species of putative hominins, such as s Sahelanthropus tchadensis and Orrorin tugenensis. These fossil records show anatomical features, such as a more anteriorly positioned foramen magnum, a vertically orientated spinal column, as well as various
Researchers over the years have worked on different hypothesis and models in an effort to explain the reasons behind the development of bipedal locomotion in the human lineage. The possible explanations for bipedalism deal with several different issues, and although they all present interesting points for debate, anthropologists still have not been able to advance one definitive and indisputable theory to explain the emergence of bipedal locomotion in hominins. In fact, it could be argued that merely one explanation for the development of this trait in humans might not be satisfactory and that bipedalism could have possibly appeared and developed because of a combination of several
The main idea presented by this theory was that early humans developed bipedal locomotion in order to be able to adapt from a forest environment to drier, more open landscapes, such as the grassy plains that characterise some areas in Africa today. The early, “classic” version of this theory suggested that this change in the environment was the cause for the development of bipedalism in hominins, as well as that of cognitive and behavioural evolution. One of the main criticisms towards this theory was the lack of hard evidence linking environmental change and human evolution. Studies conducted in the last few decades in association with other areas of research, such as geology and zoology, have produced data that might support this theory, however, there have also been several studies whose results have come to contradict the savanna theory (Shreeve, 1996). Indeed, not only does most evidence in the field of paleoanthropology seem to show that the causes for the origin of bipedalism are much more complex than what this theory suggests, but some recent studies suggest that bipedal behaviour might have actually first occurred on trees and not on the