Human evolution from an ancestral primate species is not a vague hypothesis, but a historical fact. Archaeological geology as a science had to precede the proposal of evolution, as an understanding of the immense age of the earth is necessary to understand evolution. Cuvier established amongst the scientific community the fact of extinction. Evolution only gained significant momentum after the theory of evolution, published by Charles Darwin implied that man was merely another product of life on earth, with origins shared by the other creatures and not its ultimate purpose. Absolute dating methods such as the potassium/argon and argon-argon methods of dating fossils provide a precise measure of the date of fossil remains or associated minerals. Relative dating methods rely on characteristic faunal and geological patterns to bracket the period when the fossil existed. At the onset of the 20th century, most scientists had accepted the great antiquity of the earth, the theory of evolution and that humanity had evolved from an ape ancestor, but by 1908 the fossil evidence of early man was scarce. Biologists included principles from genetics in evolutionary theory during the 1920s and 1930s. Between the mid-1930s and mid 1940s geneticists, systematists and paleontologists collaborated to create a united approach to evolution, the “Modern Synthesis”. Ernst Mayr reduced all the hominid (human ancestor) fossil records to three species, A. africanus (including small brained australopithecines), H.erectus (including the Java and Peking hominids – the archetypal Missing Link) and H. sapiens (including Neanderthals and Cro-Magnon). Based on fundamental research on the influence of diet on primate evolution, scientists propose that adaptations to a specific diet in our ancestors paved the way for the development of modern humans. Our dentition, with reduced canines and incisors and large molars and premolars reflect dietary modifications. Our closest living relative, the.