the theory that evolutionary change has occurred during short periods of rapid change punctuated by periods of stability Such a process would be characterized by the absence of an infinite range of intermediate forms, and supporters of the theory point to the vertebrate fossil record as evidence.
Further insight on the applicability of the punctuated equilibrium model might be gained by revisiting Gersick's (1988) distinction between two streams of literature in which universal stages of group activity have been investigated.
The issues we have raised beg the question of the specification of the punctuated equilibrium model of group development and its component constructs.
In addition to predicting stability of a group's task progress within each stage, Gersick's description of the operation of the punctuated equilibrium model tells us that relatively little visible progress should be expected before the midpoint transition, and relatively significant advances should be expected to emerge afterwards.
Thus, the punctuated equilibrium model clarifies little about how the group is more developed after the midpoint than before it.
In the punctuated equilibrium model of group development, temporal pacing before versus after the midpoint is presented as the central construct.