Human evolution is the biological and cultural development of the species Homo sapiens or human beings. Humans evolved from apes, because of their similarities. This can be shown in the evidence. Early humans are classified in ten different types of families.Humans belong to the mammalian family Primates- In this arrangement, 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 similarities. Two-leg walking seems to be one of the earliest of the major hominine characteristics. In the course of human evolution, the size of the brain has been more than tripled. The increase in brain size may be related to changes in human being behaviour. The third major trend in hominine development is the gradual decrease in the size of the face and teeth.Between 7 and 20 million years ago, primitive apelike animals were widely distributed on the African and on the Eurasian continents. Ancestors of modern humans are divided into the category Australopithecus and Homo. They appeared about 5 million years ago. The history of human being begins with the australopithecines. According to Britannica Encyclopedia, Australopithecus already lived in Kenya about 4 million years ago. This australopithecine had a brain size a little larger than chimpanzees. No tools of any kind have been found with this distant human ancestor. According to Encarta Encyclopedia, Homo erectus lived from about 1,8 million to 30,000 years ago. Until recently, Homo erectus was considered an evolutionary ancestor of modern humans, or Homo sapiens. Homo erectus had a larger brain than earlier hominines. Homo erectus was also taller, with an evenly face and smaller teeth. Homo habilis is the earliest known member of the genus Homo. Homo habilis had a larger brain than australopithecines. Australopithecines had long arms and short legs, similar to those of apes. Homo habilis was taller than australopithecines, but shorter than Homo erectus.The theory of evolution is the most reasonable theory today and is actual living proof that humans did evolve from apes and why the environmental adaptations have made humans the dominant creatures on the earth.