human evolution

(human skulls)

Evolution of the Human Skull
The human skull has changed dramatically through the past 3 million years. As the skull evolved from Australopithecus to Homo (sapiens) sapiens, the capacity of the cranium increased (to accommodate the growth of the brain), the face flattened, the chin recessed, and the size of the teeth decreased. Scientists believe that the incredible growth in the size of the brain may be related to the increasing sophistication of hominine behavior. Anthropologists also theorize that the brain evolved a high capacity for learning and reasoning, and after that cultural, not physical, evolution changed the way humans live.

Gorilla Skull versus Human Skull
Modern human beings, like gorillas, and chimpanzees, are primates. Some time along the course of primate evolution, human development diverged from that of gorillas and other primates. Although many similarities exist between other primates, particularly gorillas and chimpanzees, and modern humans, fundamental differences attest to the divergence in development. This illustration of the skulls of a modern gorilla and a modern human show some of these differences. The gorilla has larger canine teeth and a protruding jaw as compared with members of the hominid line.

Australopithecus Afarensis
Australopithecus afarensis is the earliest known hominid species. The lighter portions of the skull cast represent actual bone fragments, while the dark areas represent what the entire skull might have looked like. Australopithecus is believed to have lived from 3 or 4 million years ago to 1.5 million years ago.

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