Thomas F Hansen
Rupert Riedl did not use the term evolvability, but his writings and teachings in the 1970s and 1980s were important precursors and influences on the research that became associated with the term when it appeared in the 1990s. Riedl served as a motivator for many researchers that later took up questions related to evolvability, and also had an indirect influence in that Riedl-inspired researchers created a research program to combine the systems thinking that Riedl championed with the theoretical population genetics of the modern synthesis. Notably, this was despite a near-total absence of population perspectives in Riedl's personal research. In this essay I review some of Riedl's perspectives on evolvability, speculate on his influence on later evolvability research, and review what we have later learned about the questions and perspectives initiated by him.