With the general acceptance of the doctrine of organic evolution continuity between human history and natural history was also accepted. The latter became just the latest chapters in a single historical record with archaeology bridging the gap between the record of the rocks and the written record. The content of these latest chapters may be termed social evolution, and the Darwinian mechanisms of variation, adaptation, selection and survival may be invoked to elucidate the history of man as well as that of other organisms. But while the use of these terms may emphasize the continuity of history, it may also cause confusions and, in fact, misled some early anthropologists and archaeologists when they tried uncritically to apply Darwinian formulae to human societies or artifacts.