"The modern evolutionary synthesis ( often referred to simply as the new synthesis , the modern synthesis , the evolutionary synthesis , neo-Darwinian synthesis or neo-Darwinism ) , generally denotes the integration of Charles Darwin 's theory of the evolution of species by natural selection , Gregor Mendel 's theory of genetics as the basis for biological inheritance , random genetic mutation as the source of variation , and mathematical population genetics . Major figures in the development of the modern synthesis include Thomas Hunt Morgan , R. A. Fisher , Theodosius Dobzhansky , J.B.S . Haldane , Sewall Wright , Julian Huxley , Ernst Mayr , Bernhard Rensch , George Gaylord Simpson , and G. Ledyard Stebbins . Essentially , the modern synthesis introduced the connection between two important discoveries : the units of evolution ( genes ) and the mechanism of evolution ( selection ) . It also represents a unification of several branches of biology that previously had little in common , particularly genetics , cytology , systematics , botany , and paleontology ."
"and further :"
"The modern evolutionary synthesis ( often referred to simply as the new synthesis , the modern synthesis , the evolutionary synthesis , neo-Darwinian synthesis or neo-Darwinism"
"and further :"