14c dating method
Our hominoid line, humans, gorillas, chimpanzees and lesser apes, is one among the superfamily Hominoidea.
See the taxonomic table of primates for two comparative classification shcemes.
Once multicellular organisation became possible as atmospheric oxygen levels rose, the early multicellular organisms rapidly diverged into many adaptive forms.
Mass extinction events and an organism's unique adaptations mark the history of evolution, both of which may lead to adaptive radiation.
Between the mid-1930s and mid 1940s geneticists, systematists and palaeontologists collaborated to create a united approach to evolution, the "Modern Synthesis".
Ernst Mayr reduced all the hominid (human ancestor: (see hominid books)) fossil records to three species, A.
africanus (Dart, 1925) (including small brained australopithecines) (see books), H.
erectus (including the Java and Peking hominids - the archetypal Missing Link) and H.
Cuvier established amongst the scientific community the fact of extinction.
Very simply, there are five basic principles to this theory:  Variation has a genetic origin (i.e.
is heritable) and arises through processes such as mutation and recombination.
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.