Our pelvis developed in two stages
Upright walking was a crucial breakthrough in human evolution. Only through stable bipedal locomotion were our ancestors able to free their hands to create and use more complex tools. While great apes – our closest relatives – can also stand upright for short periods, they lack the anatomical prerequisites to position their torso and head vertically above their legs and feet. As a result, gorillas, chimpanzees, and other apes cannot stand upright and maintain their balance.
Source: Bild der Wissenschaft
Author: Nadja Podbregar
Link: Full Text