What are the major differences between apes and humans?

• The earliest difference, clearly encountered even in early forms of australopithecines, is an upright posture and an efficient bipedalism (walking on the hind legs) in humans. Associated with the erect posture is the tendency of the skull to sit roughly centered atop the vertebral column. In apes, the column attaches to the rear of the skull. In upright human forms, this repositioning of the skull provides greater support for the cranium and encourages a straight vertical position for the entire body.

• In apes, the big toe of the foot is long and opposable to the other toes. In all members of Homo, the toe is smaller and is in line with the other toes. Although the human foot is no longer readily prehensile, the five aligned toes provide a better base support for the upright animal.

• Both the jaws and the teeth are considerably reduced in humans. This makes the snout narrower. The lips are extremely motile and more readily serve such social functions as speaking and kissing.

• The brow ridges of the ape are considerably reduced in humans. Instead, a smooth, high forehead exists and is associated with extra cranial room for the forebrain.

• Closely associated with the increased brain size, especially in H. sapiens, was the creation of a complex symbolic culture. Among the characteristics of that culture was an elaborate toolmaking ability.