Living things react to the world with a situational specificity not predicted by the underlying physical law, and people react to the world, and to each other, with a specificity not predicted by the underlying biology. Situational precision is guided by complex constraints, sequences of DNA in biology and sequences of text in our literate technological civilization. However, sequences do not act directly. Rather, they rely on third-party mechanisms, on constraints called interactors that are constructed or configured to couple pattern recognition to appropriate behavior. The environmental complement of the interactor is the affordance, the salient feature of the world that invites an appropriate response. In the cell, the interactors are enzyme molecules. In human culture they are humans themselves. Sequences are organized into descriptive and instructive elements, nouns and verbs in the case of language: see this, do that. Genes also have discrete subsequences corresponding to pattern recognition and others corresponding to catalytic manipulation, the molecular equivalents of nouns and verbs. Coupling a noun to a verb describes an affordance, and endless affordances can be described by coupling different nouns to different verbs, at either the human or molecular level. In the cell, this is facilitated by alternative splicing.