Human ancestors walked 3.6 million-years ago

[Still Waters]

Humans are walkers, and we’re really good at it. Other creatures can walk on two legs — chimpanzees, for example, walk with bent knees and bent hips, kind of like Groucho Marx — but no animal walks the way we do, with the torso vertical, the legs extended, the stride long.

Paleoanthropologists point out that the ability to walk, and to do so with a minimum of expended energy, predated the evolution of big brains among human ancestors. Walking freed the hands for tools and weapons, and allowed those species to roam far and wide to obtain food and other resources.

But when did our ancestors begin to walk the way we do?

https://www.sciencealert.com/when-did-human-ancestors-walk-on-two-legs-3-6-million-years-evolution

[Piney]

I actually think the trait evolved on the Savannah because of lack of trees and plenty of big cats. I also think it quicky evolved into running really fast to get to the nearest "safe space".