When the German chemist Emil Fischer presented his key-lock hypothesis
in 1899, his analogy to describe the molecular relationship between
enzymes and substrates quickly gained vast influence and provided future
generations of scientists with a tool to investigate the relation
between chemical structure and biological specificity. Rebecca Mertens
explains the appeal of the lock-and-key analogy by its role in model
building and in the construction of long-term, cross-generational
research programs. She argues that a crucial feature of these research
programs, namely ascertaining the continuity of core ideas and concepts,
is provided by a certain way of analogy-based modeling.