Answer:
punctuated equilibrium
Step-by-step explanation:
Punctuated equilibrium a model of evolution that explains evolutionary pattern as exhibited by fossils. According to punctuated equilibrium, a species undergoes a long period of no change or no evolution. This period of no change is called "stasis". And stasis is sometimes interrupted by a rapid phase of evolution. This pattern of evolution with long static phage interrupted by rapid phage of changes is called punctuated equilibrium.