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 developmental psychology rather than adaptive behavior. While EDP theory generally aligns with that of mainstream EP, it is distinguished by a conscious effort to reconcile theories of both evolution and development. EDP theory diverges from mainstream evolutionary psychology in both the degree of importance placed on the environment in influencing behavior, and in how evolution has shaped the development of human psychology. Advocates of EDP assert that evolutionary psychologists, while acknowledging the role of the environment in shaping behavior and making claims as to its effects, rarely develop explicit models (i.e., predictions of how the environment might shape behavior) to support their