This chapter focuses on evolutionary implications that can be inferred from the existence of within-plant variation in organ traits and the associated ecological phenomena mediated by interactions with animals. The adaptive levels of environmental phenotypic variance in organ traits can be maintained by selection, regardless of the mechanisms producing it. Subindividual variability often accounts for nontrivial proportions of total environmental phenotypic variance of organ traits; selection by animals on variability has the potential to modify the magnitude of environmental variance and, in...

This chapter focuses on evolutionary implications that can be inferred from the existence of within-plant variation in organ traits and the associated ecological phenomena mediated by interactions with animals. The adaptive levels of environmental phenotypic variance in organ traits can be maintained by selection, regardless of the mechanisms producing it. Subindividual variability often accounts for nontrivial proportions of total environmental phenotypic variance of organ traits; selection by animals on variability has the potential to modify the magnitude of environmental variance and, in so doing, shift the balance between the genetic and environmental components. It is suggested that the environmental and genetic factors may be envisaged as “competing” to produce a given level of phenotypic variance. Thus, the spatial and temporal dynamics of such competition has manifold evolutionary implications, and animals can play a driving role by shifting the balance toward one side or the other.