RESUMO
This article explores the emergence of molecular approaches in German genetic research during the 1958-1968 decade as a period of contingency and alternative possibilities. We introduce "Narratives of Contingency" as an analytical framework to examine how scientists construct a specific narrative - linking past experiences with expectations of future conditions - in order to outline and navigate pathway-decisions in the present. We apply this framework to Hans-Jörg Rheinberger's developmental model of molecular genetics and illustrate how the stages he identifies - the direction of the field, institutional developments, and epistemological demarcations - were already central themes in the comparative practices underlying narratives of contingency in this early period. Narratives of contingency can thus serve as a systematic framework for analyzing the processes through which new scientific fields, institutions, and epistemic horizons emerge, and possibly also for identifying historically plausible fork moments or alternative pathways not taken.