It’s a few things that stem from bipedalism:
- We can run and breathe entirely separately. Most quadrupeds lack the ability to run and take breaths independently of the pace of each step. Watching cheetahs sprint, for example, show that they have no choice but to exhale every time their legs come together and inhale every time their legs push apart.
- Running on our hind legs only frees up our hands to be able to use tools and weapons, maybe even water containers for drinking on the go.
- We can see further by standing up, and can make tactical decisions based on terrain, while still running pretty much full speed.
Combined with our unusual ability to cool ourselves by sweating, this gives us an advantage over pretty much any animal in the heat. Wolves and horses can still outrun humans in the cold, but lack the cooling mechanisms to maintain pace in the same heat that we can.
I didn’t even know he was sick!