Punctuated equilibrium

имя существительное периодически нарушаемое равновесие (тип эволюции, при котором длительный период равновесия периодически нарушается кратким периодом бурного развития) Антоним(ы): gradualism

Большой англо-русский словарь

Punctuated equilibrium

noun evolution that is characterized by long periods of stability in the characteristics of an organism and short periods of rapid change during which new forms appear especially from small subpopulations of the ancestral form in restricted parts of its geographic range; also a theory or model of evolution emphasizing this — compare gradualism 2

Merriam-Webster's Collegiate Dictionary