According to researchers at the University of Kansas, they have published a study which suggests a possible reason as to why our species, learned to walk. They theorize that about 2.6 million years ago, stars exploded within the range of our planet and due to the cosmic energy that was unleashed, it resulted in extreme weathers, such as lightning strikes, which in turn caused wildfires and turned forests into grasslands.
Why this matters is because, in the very, very early days, our human ancestors were known as hominins who swung from tree to tree to get around. However, as we stated, the wildfires resulted in their habitat being destroyed, thus forcing them to adapt and find new ways of getting around, which resulted in walking.
According to Adrian Melott, the study author and professor emeritus of physics and astronomy at the University of Kansas, “It is thought there was already some tendency for hominins to walk on two legs, even before this event. But they were mainly adapted for climbing around in trees. After this conversion to savanna, they would much more often have to walk from one tree to another across the grassland, and so they become better at walking upright. It’s thought this conversion to savanna contributed to bipedalism as it became more and more dominant in human ancestors.”