Ashman, Tia-Lynn; Morgan, Martin. 2004. Explaining phenotypic selection on plant attractive characters: Male function, gender balance or ecological context?. Proceedings of the Royal Society B-Biological Sciences. Vol: 271(1539). Pages 553-559. (Abstract) (Online version)
It is widely agreed that the flowers of hermaphrodite plants evolve in response to selection acting simultaneously through male and female sexual functions, but we know very little about the pattern of genderâ€“specific selection. We review three current hypotheses for genderâ€“specific selection by viewing them within a single phenotypic selection framework. We compile data from phenotypic selection and manipulative studies and evaluate the fit between empirical data and the hypotheses. In this preliminary analysis, we find that neither the maleâ€“function hypothesis nor the genderâ€“balance hypothesis is well supported. However, the contextâ€“dependence hypothesis is supported by the documented diversity of genderâ€“specific selection and by evidence that selection through female fertility is significantly correlated with pollen limitation of seed production. Future studies contributing to our understanding of selection through male and female function in plants need to quantify and manipulate the ecological context for reproduction, as well as describe male and female fitness responses to fineâ€“scale trait manipulation.