Gradualism

Charles Darwin was the first to propose gradualistic biological evolution as a uniformitarian explanation of change and diversification of living things. Darwin's theory explained past changes as products of the same forces that cause small, adaptive, incremental changes in natural populations today, but extended over long periods of time. Since Darwin's time, many new ideas and discoveries have reshaped the concept of gradualism. The most important of these was the neo‐Darwinian evolutionary synthesis of the early twentieth century. The concept of gradualism was also affected by discussions of punctuated equilibrium, which was promoted as being an alternative to Darwinian or neo‐Darwinian gradualism. The current consensus, however, holds that gradualistic changes can be rapid as well as slow. Research in the twenty‐first century has already shown that cladogenesis can be quite slow, while gradual changes can be much more rapid. Evolutionary stasis is now recognized as a point at one extreme of a continuum of evolutionary rates.