When a toddler takes its first steps, it's a formative experience for both parent and child. Walking upright is an inherent part of being human. And for centuries, scientists have been asking how primates, including us, evolved this ability,
It's a much bigger question than it seems. Most animals, including most mammals, are quadrupeds (or greater — many arthropods and insects have six or more legs). We, and a few other primates, are bipedal — meaning we walk on two feet rather than four. Understanding why we took on this trait can tell us more about how humans evolved, including our brain development. Because bipedalism allows for greater conservation of energy, not to mention freeing up our arms to carry tools, some anthropologists believe this behavior contributed to our brain size.
