The fossil evidence proves this. The existence of these part ape, part humans, proves that humans evolved.
Ramapithecus evolved into Australopithecus 10 million years ago. Australopithecus evolved into Homo erectus.
The Facts Are .....
Australopithecine theories have been based on the meagre evidence of:- a single front face; several lower jaws; numerous teeth; a nearly complete skull; portions of a pelvis; fragments of long bones, and the ends of a few limb bones. These few totally unrelated specimens have been lumped together to produce the hypothetical features of fully grown animals. There is no guarantee that these fragments all came from the same species of individual, so any statements are pure speculation. Malcolm Bowden,
"Ape-Men: Fact or Fallacy", (2nd ed.), Sovereign Publications: Kent (UK), 1981 p:177-178
Observation of Australopithecine fossils by some respected anthropologists has revealed that they are most likely apes rather than intermediates between apes and humans. Their brain size is similar to a chimpanzee; the teeth wear pattern is like that of a fruit-eating chimpanzee; the canine teeth are definitely ape-like; the skull of Australopithecus afarensis looks like a small female gorilla; the foot bone of Australopithecus afarensis is curved like a chimpanzee; and their hind limb structure is most like that of the orangutan. Richard Leakey, "The Making of Mankind", Abacus: London, 1982 p:69-70, 74-75, 131-133; Science, Vol. 213, July 17, 1981 p:348-349; New Scientist, September 3, 1981 p:595; American Journal of Physical Anthropology, Vol. 41, 1974 p:191
Computerized X-ray scans of Australopithecine skulls have been conducted in an attempt to examine their inner ear. The shape of the bones in the inner ear are directly related to the pattern of movement of the individual. Australopithecine structures indicate that they walked decidedly ape-like.
They are therefore not intermediates between humans and apes. New Scientist, July 30, 1994 p:26-29; Nature, Vol. 369, June 23, 1994 645-648
"The first impression given by all the skulls from the different populations of Australopithecus is of a distinctly ape-like creature ..... The ape-like profile of Australopithecus is so pronounced that its outline can be superimposed on that of a female chimpanzee with a remarkable closeness of fit .....
Australopithecus stands in strong contrast to modern Homo sapiens [ie. humans]. Written by evolutionist and palaeontologist Professor Joseph Weiner in his book "The Natural History of Man", Universe Books: New York, 1971 p:45 & 46
"The Australopithecine skull is in fact so overwhelmingly simian [ie. ape-like], as opposed to human that the contrary proposition could be equated to an assertion that black is white." Written by anatomist Sir Zolly Zuckerman (once Professor of Anatomy, University of Birmingham, Secretary of the Zoological Society of London, and Chief scientific adviser to the British Government) in his book "Beyond the Ivory Tower", Taplinger Pub. Co: London, 1970 p:78
"In each case although initial studies suggests that the [australopithecine] fossils are similar to humans, or at the worst intermediate between humans and African apes, study of the complete evidence readily shows that the reality is otherwise." Written by evolutionist, anatomist & biologist Dr Charles Oxnard (Professor of Anatomy and Human Biology, University of W.A.) in his book "Fossils, Teeth and Sex: New Perspectives on Human Evolution", University of Washington Press: Seattle, 1987 p:227
"As far as geologically more recent evidence is concerned, the discovery in East Africa of apparent remains of Homo [sapiens] in the same early fossil sites as both gracile and robust australopithecines has thrown open once again the question of the direct relevance of the latter to human evolution. So one is forced to conclude that there is no clear-cut scientific picture of human evolution." Written by Dr Robert Martin (Senior Research Fellow, Zoological Society of London) in his article "Man is not an Onion" in New Scientist, August 4, 1977 p:285