The pattern that began 40-35,000 years ago in Europe is one of frequent--if not continual--change in human culture. The succeeding 30,000 years are subdivided into cultural periods, each with its own style of technology and each characterized by a set of innovations. Many of these new ways of doing things were undoubtedly stimulated by practical need. But the evidence often gives the impression of change for the sake of change--something familiar to most modern humans as "fashion."