The (relative) importance of pollinator‐mediated selection for evolution of flowers

Abstract

Perhaps the most intriguing example, surely the most aesthetic, of plant evolution is the interaction of fl owers and their pollinators, which has sparked a burst of studies spanning diverse disciplines, from animal behavior to plant genetics. Starting in the late 1700s ( Sprengel, 1793 ) and emphasized by Darwin (1862) , pollination was accepted as the driver of fl oral variation, making pollinatormediated selection the major paradigm for fl ower evolution. Indeed, numerous studies support the hypothesis that adaptation to pollinators commonly contributes to fl oral diversity ( Harder and Johnson, 2009 ). Pollinators are considered to select not only for a single traits, but also for sets of correlated traits (pollination syndromes; Fenster et al., 2004 ). Pollinators are also thought to be agents of divergent selection that can lead to speciation and maintain species boundaries, based on divergent trait values.