- The Paleontological Society
The thoughts and writings of Stephen Jay Gould have had an enormous impact on the shaping of macroevolutionary theory. The notion of punctuated equilibria (Eldredge and Gould 1972) remained prominent throughout his work. It also unleashed a storm of debate in paleontology and evolutionary theory. A second theme that recurs throughout Gould's opus is heterochrony (evolution by changes in the rates and timing of ontogenetic events, sensu Gould 1977a). His analyses of these two subjects have inspired many of us to explore further and add to them. My contribution discusses their expansion to encompass large numbers of lineages through long time, and the relationship of punctuated equilibria and heterochrony to physical environmental change, and to each other.