Oral Paper

         Macroevolution

Macroevolutionary patterns in flower and fruit colors

Presenting Author
Miranda Sinnott-Armstrong
Description
As part of their reproductive lifecycles, many plants partner with animals to achieve pollination and/or seed dispersal.  As part of this mutualism, plants produce a variety of colors in their flowers and fleshy fruits in order to attract animals.  In both animal-pollinated flowers and animal-dispersed fruits, “syndromes” of traits have been suggested that link traits to particular pollinators or dispersers.  Flowers have been studied in considerably greater depth than fleshy fruits, despite the importance of both flowers and fruits in the plant life cycle.  Here, we examine the evolution of flower color and fruit color in 1200+ species across 43 clades of plants that are animal-pollinated and animal-dispersed.  We use diversity indices and stochastic character mapping to assess whether flower or fruit colors are more diverse and to characterize patterns in their evolution. We find that, within a clade, fruit colors tend to be more diverse than flower colors, and that fruit colors evolve faster than flower colors.  Additionally, our data suggest that flower colors and fruit colors tend to evolve along predictable axes of variation. Flower color transitions within the same biochemical pathway (e.g., anthocyanins) are more common than transitions across biochemical pathways. Fruit colors, on the other hand, tend to evolve within the so-called “syndromes” associated with mammal and bird dispersal.  These findings suggest that, although the colors of both flowers and fruits are generally assumed to be selected by animal pollen/seed dispersers, in fact these two similar traits display very different evolutionary trajectories that are likely constrained by different factors.