We might have lost it because of our unique mode of bipedal locomotion.
由于我们独特的双足运动方式,我们可能已经失去了它。
英语百科
Bipedalism
(重定向自Bipedal Locomotion)
Bipedalism is a form of terrestrial locomotion where an organism moves by means of its two rear limbs or legs. An animal or machine that usually moves in a bipedal manner is known as a biped/ˈbaɪpɛd/, meaning "two feet" (from the Latin bis for "double" and pes for "foot"). Types of bipedal movement include walking, running, or hopping.