Question

Loss of tail is characteristic of all apes. So are the other first two characters. Shortening of jaws is specific evolutionary trait of humans.

Answer 1

Apes and humans differ from all of the other primates in that they lack external tails. Early hominin faces were large relative to the size of their brain cases. They had comparatively big molar teeth with thick enamel. By comparison, their front teeth were small. They had large jaws, and powerful jaw muscles. In modern humans, the jaw muscles are much smaller and attach onto the skull in the temple region.