Using genomic studies to examine plant pollinator interactions will shed light on the complex interactions involved in successful pollination and pollinator-mediated evolution (Clare et al., 2013).
The need to attract pollinators has led to the evolution of pollination syndromes, which are defined as groups of "floral traits, including rewards, associated with the attraction and utilization of a specific group of animals as pollinators".
Our findings are consistent with the idea that environment and availability of pollinators are important in the evolution of pollination syndromes.
Because male flowers reward biotic pollinators with both pollen and nectar, while females only produce nectar, some biotic pollinators might discriminate against female flowers, resulting in reduced female fertility and favoring the evolution of wind pollination or pollination by less-discriminating pollinators [ 44, 45].
We suggest that high amounts of alkenes evolved for the attraction of primarily male bees as pollinators by sensory exploitation, and discuss possible driving forces for the evolution of pollination by male bees.
Sometimes additional questions are addressed using data on the evolution of pollination systems.
A well known example is the tropical vine genus Dalechampia, where resins are produced primarily for herbivore deterrence [ 35]; this trait was a preadaptation for the evolution of pollination systems based on resin reward [ 34, 36].
Although a great deal has been written about the diversity and evolution of pollination drops within a morphological context (Doyle, 1945; Owens et al., 1998; Gelbart and von Aderkas, 2002), far less is known about their biochemistry (Nepi et al., 2009) and physiology (Tomlinson et al., 1997; Runions et al., 1999; Mugnaini et al., 2007).
We conclude that herbivores, as well as pollinators shape the evolution of floral traits and that it makes little sense to study floral traits as if they only mediate pollination services.
Preadaptations of pollinators have also been assumed to influence the evolution of specialized pollination systems, such as that observed in the yucca – yucca moth mutualism [ 45].
