punctuated equilibrium
A theory in evolutionary biology proposing that species experience long periods of stability interrupted by brief periods of rapid change.
The theory of punctuated equilibrium was proposed by Stephen Jay Gould and Niles Eldredge.
進化論 is the general term for the theory of evolution, while 断続平衡説 refers specifically to the punctuated equilibrium model within evolutionary biology.
Compound of 断続 (intermittent, discontinuous), 平衡 (equilibrium), and 説 (theory). The term is a direct translation of the English 'punctuated equilibrium'.