The evolution of dominance concerns the evolution of genetic dominance. The central argument, that modifier genes act upon other genes to make them dominant or recessive, and that these are then themselves subject to natural selection was first proposed by the British population geneticist Ronald Fisher in 1928, and expanded upon in his book The Genetical Theory of Natural Selection. However, Sewall Wright and J.B.S. Haldane believed that the main explanation for dominance should be based on physiological factors, and that selection for modifiers was not a primary force. This led to a major fallout between Fisher and Wright. Subsequent works, particularly in molecular biology and biochemistry, have tended to favour Wright's view without completely excluding that the Fisherian argument may, in some circumstances, apply.