Pollination Syndromes: A Global Pattern of Convergent Evolution Driven by the Most Effective Pollinator

Abstract

Convergent evolution of floral traits driven by pollinators has resulted in fl oral syndromes shared among different plant lineages. However, the flowers of many plant species are often visited by different pollinator groups, which apparently contradict the idea of syndromes. Here, we demonstrate that the most efficient pollinators consistently correspond to the ones predicted by the syndrome, and the predictive accuracy of the syndrome tends to be higher for species pollinated exclusively by one functional group than for species pollinated by more than one functional group. Secondary pollinator functional groups affected deferentially the relative efficiency of the primary pollinator depending of the syndrome. The most frequent secondary pollinator group of a given syndrome is also the least efficient one. Floral symmetry did not influence predictability of pollination syndromes. Except for the bee-syndrome plants, pollination syndromes were more effective on plants that depend strongly on animal pollination than on less dependent plants. Last, effective pollinators for each fl oral syndrome were better predicted for plants from tropical regions, particularly for the bat, bee, and bird syndromes. Our results have implications on the effects of global change on floral evolution and suggest that current suites of fl oral traits in most plant species have the potential to adapt to new conditions under changing selective pollination environments.