Genetics and the Origin of Species provided the outline for a synthesis of genetics with evolution, and was enthusiastically received by both geneticists and naturalists. Dobzhansky laid out an advanced account of the evolutionary process in genetic terms, and he backed up his work with experimental evidence supporting the theoretical arguments. This led to the stimulation of the field of evolutionary genetics, and contributions to the theory soon began to follow. This had a powerful impact on naturalists and experimental biologists, who quickly embraced this new understanding of the evolutionary process as one of genetic change in populations.Jr., Lloyd T. Ackert. "Theodosius Grigor'evich Dobzhansky." In Science and Its Times, 160-61. Detroit: Gale, 2000, p. 160-161. It was not long before the synthesis was broadened to include paleontology, systematics and botany in a series of notable books: Systematics and the Origin of Species (1942) by Ernst Mayr; Tempo and Mode in Evolution (1944) by George Gaylord Simpson; and Variation and Evolution in Plants (1950) by G. Ledyard Stebbins. The emerging synthesis was called the evolutionary synthesis by Julian Huxley in his book, Evolution: The Modern Synthesis. In 1947, a diverse collection of biologists met at a symposium in Princeton and declared their acceptance of this synthesis. However, it was not yet complete. Developmental biologists did not accept that the theory explained their observations, and it was not until the 1970s and 1980s that molecular biology bridged the gap. Also, for decades there was disagreement over whether the unit of selection was the gene or the individual as a whole.
