Modern synthesis (20th century)

The modern synthesis, was the early 20th-century synthesis reconciling Charles Darwin's theory of evolution and Gregor Mendel's ideas on heredity in a joint mathematical framework. Julian Huxley invented the term in his 1942 book, Evolution: The Modern Synthesis.

The 19th century ideas of natural selection by Darwin and Mendelian genetics were put together with population genetics, early in the twentieth century. The modern synthesis also addressed the relationship between the broad-scale changes of macroevolution seen by palaeontologists and the small-scale microevolution of local populations of living organisms. The synthesis was defined differently by its founders, with Ernst Mayr in 1959, G. Ledyard Stebbins in 1966 and Theodosius Dobzhansky in 1974 offering differing numbers of basic postulates in their definitions, though they all included natural selection, working on heritable variation supplied by mutation. Other major figures in the synthesis included E. B. Ford, Bernhard Rensch, Ivan Schmalhausen, and George Gaylord Simpson. An early event in the modern synthesis was R. A. Fisher's 1918 paper on mathematical population genetics, but William Bateson, and separately Udny Yule, were already starting to show how Mendelian genetics could work in evolution in 1902.