 Anthropologists once thought that the common ancestor of chimpanzees and humans engaged in knuckle-walking, and humans evolved upright walking from knuckle-walking : a view thought to be supported by reanalysis of overlooked features on hominid fossils.
<fluency>  Anthropologists once thought that the common ancestor of chimpanzees and humans engaged in knuckle-walking, and humans evolved upright walking from knuckle-walking : a view thought to be supported by reanalysis of overlooked features on hominid fossils.
 Anthropologists once thought that the common ancestor of chimpanzees and humans engaged in knuckle-walking, and humans evolved upright walking from knuckle-walking , a view thought to be supported by reanalysis of overlooked features on hominid fossils.