The nature of change.

There is little doubt that health care is facing change. The conventional view of change, based on evolution, is that it is slow, gradual, and generally an evenly paced system change. Unfortunately, it is much more uneven, being burstlike, unpredictable, and, in fact, steplike. This pattern is called punctuated equilibrium, which is well illustrated by the metaphorical picture of the Devil's Staircase. These features call for a reassessment of how to cope with change. In addition to detecting change, responding to it and preparing for it require some understanding of the role of experimentation because the evolution algorithm is simple: experimentation, selection, and replication. Experimentation in radiology forms a continuum ranging from modifying traits to developing variants of diagnostic, interventional, and even new integrated services. We often describe experiments by relating their motives (ie, adaptation and innovation), but complex systems see only experiments available for selection. Experiments generating new services and business models are the important ones because they create the "subspecies" of radiology, which offers a robust set of options capable of withstanding new health care selection forces. Experimentation and selection are the prerequisites of replication (i.e., survival). It behooves radiology to combine and concatenate diversified, reactive, and innovative experiments to explore adjacent domains to expand its set of options. Just as in Darwinian evolution, major changes on the health care landscape will be at the specialty, ie, species and subspecies levels, rather than at the individual specialty trait level. Radiology needs a strong set of "subspecies" to succeed in selection to enhance evolution and allow replication.