Human Evolution
Human Evolution
Human Evolution, the biological and cultural development of the species Homo sapiens, or human
beings. A large number of fossil bones and teeth have been found at various places throughout
Africa, Europe, and Asia. Tools of stone, bone, and wood, as well as fire hearths, campsites, and
burials, also have been discovered and excavated. As a result of these discoveries, a picture of human
evolution during the past 4 to 5 million years has emerged.
Human Physical Traits Humans are classified in the mammalian order Primates; within this order,
humans, along with our extinct close ancestors, and our nearest living relatives, the African apes, are
sometimes placed together in the family Hominidae because of genetic...show more content...
Associated with these changes is a gradual reduction in the size of the face and jaws. In early
hominines, the face was large and positioned in front of the braincase. As the teeth became smaller
and the brain expanded, the face became smaller and its position changed; thus, the relatively small
face of modern humans is located below, rather than in front of, the large, expanded braincase.
Human Origins The fossil evidence for immediate ancestors of modern humans is divided into the
genera Australopithecus and Homo, and begins about 5 million years ago. The nature of the
hominine evolutionary tree before that is uncertain.
Between 7 and 20 million years ago, primitive apelike animals were widely distributed on the African
and, later, on the Eurasian continents. Although many fossil bones and teeth have been found, the
way of life of these creatures, and their evolutionary relationships to the living apes and humans,
remain matters of active debate among scientists. One of these fossil apes, known as
Sivapithecus, appears to share many distinguishing features with the living
Asian great ape, the orangutan, whose direct ancestor it may well be. None of these fossils,
however, offers convincing evidence of being on the evolutionary line leading to the hominid family
generally or to the human subfamily in particular. Comparisons of blood proteins and the DNA of
the African great apes with that of humans indicates that the line leading to modern people did
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