The article discusses evolutionary aspects of mimicry from a semiotic viewpoint. The concept of semiotic scaffolding is used for this approach, and its relations with the concepts of exaptation and semiotic co-option are explained. Different dimensions of scaffolding are brought out as ontogenetic, evolutionary, physiological and cognitive. These dimensions allow for interpreting mimicry as a system that scaffolds itself. With the help of a number of mimicry cases, e.g. butterfly eyespots, brood parasitism, and plant mimesis, the evolutionary dynamics of mimicry (...) in the open bio-semiosphere is investigated. The main argument is that biological mimicry largely develops through sign relations and communicative relations between organisms. It is proposed that mimicry systems should be described as two-layered structures composed of the ecological composition of the species involved and the semiotic structure of their communication. (shrink)