The July 17 Issue of PNAS has an article citing the energy efficiency of bipedalism. This article proposes that being bipedal helps reduce energy costs associated with moving about. By measuring the energy consumption of chimps and humans on a treadmill, Herman Pontzer’s team, from Washington University in St Louis, found that for a given weight, humans used only one-quarter of the energy as the chimps.
Such energy savings may equate to reduced costs incurred during foraging for food.
For the abstract :
Article in Foxnews:
Walking on Two Legs Better Than Four, by Ker Than