Shifting balance theory Shifting balance theory The shifting balance theory is a theory of evolution proposed in 1932 by Sewall Wright, suggesting that adaptive evolution may proceed most quickly when a population divides into subpopulations with restricted gene flow. The name of the theory is borrowed from Wright's metaphor of fitness landscapes (evolutionary landscapes), attempting to explain how a population may move across an adaptive valley to a higher adaptive peak. According to the theory, this movement occurs in three steps: Although shifting balance theory has been influential in evolutionary biology, inspiring the theories of quantum evolution and punctuated equilibrium, little empirical evidence
The Theory of Evolution The Theory of Evolution The Theory of Evolution is a book by English evolutionary biologist and geneticist John Maynard Smith, originally published in 1958 in time for 150th anniversary of the birth of Charles Darwin and the centenary of the publication of "The Origin of Species" the following year. It serves as a general introduction to the eponymous subject, intended to be accessible to those with little technical knowledge of the area. It has been highly successful, considered by many as the definitive publication of its type. The original version was updated several times, and a "Canto" edition, with a