 It was the emergence of population thinking in evolution which forced many scientists to adopt gradualism in the early 20th century.According to Ernst Mayr, it wasn't until the development of population genetics in the neo-Darwinian synthesis in the 1940s that demonstrated the explanatory power of natural selection that saltational views of evolution were largely abandoned.Saltation was originally denied by the "modern synthesis" school of neo-Darwinism which favoured gradual evolution but has since been accepted due to recent evidence in evolutionary biology (see the current status section).