Dear student,
Although human and chimpanzee are close relative species along the path of evolution but human are more differentiated and specialized. This is due to the differences in the cranial capacity of human and chimpanzee. Cranial capacity of chimpanzee is 400 cc while that of human ranges between 1400 to 1500 cc. Presence of more developed parietal, temporal and frontal lobes of brain in human also account for less intelligence of chimpanzee as compared to human. With their intelligence, human have evolved themselves to inhabit varied habitats. Each human group present in different climatic zones of earth developed adaptations to get adapted and accumulated certain genetic variations over the long course of evolution. Presence of these variations in different human groups accounts for higher level of differentiation in them as compared to chimpanzee.
Regards.