Final answer:
The term 'punctuated equilibrium' refers to the evolutionary model where long periods of stability are interrupted by rapid changes and speciation. It differs from the concept of gradualism, which suggests continuous, slow change over time. Punctuated equilibrium can be observed in the fossil record and is often triggered by significant environmental changes.
Step-by-step explanation:
The term that describes a pattern of long and stable periods interrupted by brief periods of more rapid change is B) Punctuated equilibrium.
Punctuated equilibrium is a model of evolutionary change where species experience little to no change for long periods, known as stasis, punctuated by episodes of rapid speciation and change. This concept contrasts with gradualism, which proposes continuous, slow change over time. In the fossil record, we can often observe long periods where species appear unchanged, interrupted by sudden shifts that correspond to new species arising quickly, often due to significant environmental changes.
For instance, after a massive environmental shift like the breakup of a supercontinent, populations may become isolated, resulting in the rapid evolution of new species— a situation conducive to punctuated equilibrium. Over time, evolution demonstrates that both patterns—gradual change and abrupt shifts—contribute to the divergence and emergence of new species.