Having studied anthropology for a short while, there are many theories regarding the evolution of bipedalism. I'm sorry to say, as far as I understand it, they

Having studied anthropology for a short while, there are many theories regarding the evolution of bipedalism. I'm sorry to say, as far as I understand it, they are all as flimsy as this one, in that they are barely based in empirical data. Not for a lack of trying, there just aren't any other species currently evolving bipedalism as far as we know. This one, however, seems flawed on the basis of internal validity: what is the link between standing in trees and walking on the ground, let alone running? The fact that this is not immediately obvious means it raises a new question for which we have to invent more theories. Occam's razor says no. If you find me dismissive, and you think surely the researchers have thought of this, I recommend having a look at the history of these theories, you'll notice their rise and fall seem more akin to fads than progress (much as predicted by Kuhn's Structure of scientific revolutions). As the encyclopedia Britannica says: "There are many theories that attempt to explain why humans are bipedal, but none is wholly satisfactory."