Neo-Darwinism

The modern synthesis was the early 20th-century synthesis reconciling Charles Darwin's and Gregor Mendel's ideas in a joint mathematical framework that established evolution as biology's central paradigm.Embryology was however not integrated into the early-20th century synthesis; that had to wait for the development of gene manipulation techniques in the 1970s, the growth in understanding of development at a molecular level, and the creation of the modern evolutionary synthesis's successor, evolutionary developmental biology. 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 united by Ronald Fisher, one of the three founders of population genetics, along with J. B. S. Haldane and Sewall Wright, between 1918 and 1932. The modern synthesis solved difficulties and confusions caused by the specialisation and poor communication between biologists in the early years of the 20th century. At its heart was the question of whether Mendelian genetics could be reconciled with gradual evolution by means of natural selection. A second issue was whether the broad-scale changes of macroevolution seen by palaeontologists could be explained by changes seen in the microevolution of local populations.

The synthesis included evidence from geneticists who studied populations in the field and in the laboratory. These studies were crucial to evolutionary theory. The synthesis drew together ideas from several branches of biology which had become separated, particularly genetics, cytology, systematics, botany, morphology, ecology and palaeontology.

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