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
Evolutionary archaeology other disciplines, such as anthropology and specifically archaeology. In other words, critics claim that there is no value of this approach and words such as ‘variation’, ‘selection’ and ‘drift’ are merely metaphorical. They state no scientific methods exist that can justify employing the theory of evolution that exists in biology and paleobiology to what is observed in the social world. Another criticism is that human culture is increasingly complex and variable thus it can’t be constrained to the same theoretical notions such evolutionary biology. In addition, critics such as, Bloch 2000; Pinker 1997 blatantly reject any evolutionary analysis of culture.