Differentiation during fig ontogeny suggests opposing selection by mutualists

Area of Science:

• Ecology
• Evolutionary Biology
• Botany

Background:

• Dioecious figs separate male and female functions, influencing co-evolution with pollinators and seed dispersers.
• Monoecious figs and dioecious figs (male/gall and female/seed) face different selective pressures regarding pollinators and seed dispersers.

Purpose of the Study:

• To test if dioecious fig syconia (gall vs. seed) and monoecious syconia differ in characteristics at different developmental stages.
• To investigate how these differences relate to attracting pollinators and seed dispersers.

Main Methods:

• Quantified syconium characteristics across 24 dioecious and 11 monoecious fig species.
• Recorded visits by frugivores to different syconium types.

Main Results:

• Seed and gall syconia are similar at the flower stage but diverge by the fruit stage.
• Monoecious syconia resemble seed syconia more than gall syconia.
• Frugivore visitation rates were higher for monoecious and seed syconia compared to gall syconia.

Conclusions:

• Syconium similarity at the flower stage likely optimizes pollination for both gall and seed figs.
• Differentiation during fruit development enhances seed dispersal for figs with viable seeds.
• Ontogenetic differences highlight divergent evolutionary responses to ecological pressures from pollinators and dispersers.