Recently I made the assertion that running was primordial, meaning existing from the beginning from our earliest development. In the distant past, humans survived by being hunters and food gatherers. Anthropologists and evolutionary biologists have concluded that this need resulted in humans adapting and becoming the best endurance animals on the planet.
The top speed a human can sprint is approximately 23 miles per hour. In the animal kingdom, that is slow. A lion can run up to 40 mph and a cheetah nearly 80 mph. Humans were not going to outrun their prey.
Humans are bipedal and relatively hairless.