Humans began to walk upright so they can carry rare resources

Summary- We walk upright because when we were in the early stages of being a more monkey like species we used four limbs instead of the modernized two. But in some cases we only used 4 limbs for the common resources. But when we found any rare resources we walked upright on two limbs carefully holding the resource. But basically researchers and scientists discovered that we actually do not what so ever use all four limbs to hold things any more. We only use our hands and sometimes are mouth (not a limb).

Critique- I thought it was just spine growth or seeing other animals do it.

Impact- Understanding why we walk upright and also a different way you can look at humans and monkeys and see the differences.