Related Experiment Video
Updated: Mar 11, 2026

Field Experiments of Pollination Ecology: The Case of Lycoris sanguinea var. sanguinea
Published on: November 25, 2016
Evolutionary consequences of ecological factors: pollinator reliability predicts mating-system traits of a perennial
Øystein H Opedal1, Elena Albertsen1, W Scott Armbruster2,3,4
1Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, NTNU, 7491, Trondheim, Norway.
Abstract:
The reproductive-assurance hypothesis predicts that mating-system traits will evolve towards increased autonomous self-pollination in plant populations experiencing unreliable pollinator service. We tested this long-standing hypothesis by assessing geographic covariation among pollinator reliability, outcrossing rates, heterozygosity and relevant floral traits across populations of Dalechampia scandens in Costa Rica. Mean outcrossing rates ranged from 0.16 to 0.49 across four populations, and covaried with the average rates of pollen arrival on stigmas, a measure of pollinator reliability. Across populations, genetically based differences in herkogamy (anther-stigma distance) were associated with variation in stigmatic pollen loads, outcrossing rates and heterozygosity. These observations are consistent with the hypothesis that, when pollinators are unreliable, floral traits promoting autonomous selfing evolve as a mechanism of reproductive assurance. Extensive covariation between floral traits and mating system among closely related populations further suggests that floral traits influencing mating systems track variation in adaptive optima generated by variation in pollinator reliability.
Related Concept Videos
Pollination and Flower Structure
Frequency-dependent Selection
Mate Choice
Genetics of Speciation
Natural Selection and Mating Preferences
Females, due to their biological roles in conception, pregnancy, and nursing,...
Formation of Species

