Table 1.

Redundancy, degeneracy, and pluripotentiality in animal communication: their translations into scenarios of complex signalling and their implications for understanding evolutionary patterns of animal communication systems.

concept	structure/function	communication scenario	system consequences	evolutionary implications
redundant	same structure/same independent function	repeated instances of a signal—repetition of a song or a display	increases robustness of a system	enables a system to maintain function in circumstances of loss (i.e. lack of transmission) of the element. Can relax selective pressure on duplicate structures and allow for functional or structural divergence
degenerate	different structures/overlapping function	two different signals or signal components serving similar functions in some signalling contexts	increases robustness and can increase the functionality of the system	enhances capacity to respond to selection. Elements can react independently to selection; can diverge over evolutionary time to incorporate new functions while maintaining, or before losing, original function(s)
pluripotent	one structure/multiple functions	the capacity of a particular signal or signal component to serve multiple functions in a display	increases efficiency and functional diversity of the system. Enables organization of coordinated responses to a signal	elements will likely be subject to multiple selective forces; any change in the signal will have multiple consequences across the system