RESULTS
Of the nine traits examined in this study, pollinators were implicated
as agents of selection on four (three defence-related and one
attractive), and herbivores on two (one defence-related and one
attractive) (Fig. 1). Pollinators generally imposed stronger selection
pressures than herbivores as a whole, and only pollinator-mediated
selection appeared to constitute an important component of ‘total’
selection overall (Table S2) – i.e., for dihydroxybenzoic acid (net
positive selection) and shikimic acid (net negative selection).
Conflicting selection – where pollinators and herbivores exerted
selection in opposing directions – was observed for inflorescence
density, for which these agents imposed positive and negative selection
respectively. However, each of the above selection regimes was in
addition seen to be diffuse – meaning that the strength of selection by
one agent was context-depended upon (or modified by) the presence or
ecological effects of the other (Fig. 1).