These two images from Your Inner Fish show the difference between chimpanzee and hominid walking patterns — one major step in our human evolution. Chimpanzees walk with their knees directly below their hips, giving them a waddling gait. Hominids like the Australopithecus afarensis (a species known for the famous "Lucy" skeleton) walked with their knees tucked inward, giving them a more energy efficient stride. We humans walk the same way that Lucy did 3.2 million years ago.
Visit our website to find full episodes of Your Inner Fish. Due to international distribution restrictions, these programs can only be streamed in the United States and Canada.