[VanShuyten]

“If they lived in trees, why did they need to walk upright?”

Climate change.
No, really.

One theory says that as the African climate dried out, groves of trees grew farther and farther apart, so the hominids that could walk best from one to another tree had a better chance to survive.

[Red Badger]

MY THEORY:

The hominids that could RUN FASTEST from one to another tree had a better chance to survive...............

[AndyJackson]

You didn’t have to outrun the lion, just the other apes who were also trying to escape.

[Leep]

Is this about the time giraffes stretch their necks so they could reach the tree leafs?