Explaining phenotypic selection on plant attractive characters: male function, gender balance or ecological context?

Area of Science:

• Evolutionary Biology
• Plant Reproductive Ecology
• Sexual Selection

Background:

• Hermaphrodite plant flowers evolve under simultaneous male and female sexual selection.
• Patterns of gender-specific selection remain poorly understood.
• Existing hypotheses offer different explanations for these patterns.

Purpose of the Study:

• To review and evaluate three current hypotheses for gender-specific selection in plants.
• To assess the fit between empirical data and these hypotheses within a phenotypic selection framework.
• To identify future research directions for understanding plant reproductive trait evolution.

Main Methods:

• Compilation of data from phenotypic selection studies.
• Inclusion of data from manipulative experiments.
• Evaluation of hypotheses using a unified phenotypic selection framework.

Main Results:

• The male-function hypothesis and the gender-balance hypothesis received limited empirical support.
• The context-dependence hypothesis is supported by observed diversity in gender-specific selection.
• Female fertility selection correlates significantly with pollen limitation of seed production.

Conclusions:

• The context-dependence hypothesis provides a more robust framework for understanding gender-specific selection.
• Ecological context is crucial for interpreting selection on male and female reproductive functions.
• Future research should integrate ecological context and fine-scale trait manipulation for reproductive studies.