What can chimps strolling down a walkway tell us about how humans learned to walk on their own two feet? More than previously thought, claim the evolutionary authors of a study recently published in Nature Communications. Hercules and Leo, the two chimps who learned to walk upright for this study in their Stony Brook University laboratory home, were also losers in a lawsuit last summer. The unsuccessful suit, brought on their behalf by the Nonhuman Rights Project and currently being appealed, asserts that a chimp is legally a person entitled to basic rights and liberties. Meanwhile, though not appearing in court, Hercules and Leo have supposedly shown Stony Brook researchers clues about how humans evolved the ability to walk.
A Surprising Twist
Chimps and gorillas do not normally walk upright, but they can for a time if they want to. However, even with training, bipedal locomotion remains unnatural and inefficient for them because of their anatomy. Hercules and Leo were trained to habitually walk on two legs. Then researchers attached motion sensors to various parts of their bodies and filmed them walking. By comparing their walk to that of human volunteers, researchers confirmed that humans and chimps do not walk the same way.