Abstract

Grene's Two Evolutionary Theories (1958), a philosophical analysis of the nature of scientific disputes, itself contributed directly to discourse in evolutionary theory. I conclude that Grene's descriptions of two rival theories of evolutionary paleontologists — those of George Gaylord Simpson, who stressed traditional Darwinian continuity, and of Otto Schindewolf, who stressed discontinuity in paleontological data — were entirely accurate. But I further argue that both Simpson, as well as Mayr and Dobzhansky, had incorporated notions of discontinuity into their earlier work, but later removed, or at least de-emphasized discontinuity, in their later work. Grene's analysis, published in the year of the Darwinian centennial, was initially treated as a provocative sore point. The paper kept the issue of discontinuity alive in evolutionary theory, and directly influenced work in the 1960s and 1970s, which restored and further elaborated on the significance of discontinuity in evolutionary theory.