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Gynodioecy to dioecy: are we there yet?
Rachel B Spigler1, Tia-Lynn Ashman
1Department of Biological Sciences, 4249 Fifth Ave., University of Pittsburgh, Pittsburgh, PA 15260-3929, USA.
Annals of Botany
|August 3, 2011
Summary
The transition from gynodioecy to dioecy is not fully understood, though females show seed fertility advantages and males gain advantages in subdioecious species. More research is needed on male fertility evolution in hermaphrodites. Keywords: gynodioecy, dioecy, sexual selection, plant reproduction.
Area of Science:
- Evolutionary biology
- Plant reproductive strategies
Background:
- The gynodioecy-dioecy pathway is a key route from hermaphroditism to separate sexes.
- Evidence supports the first step (female advantage in gynodioecy), but the second step (transition to dioecy) is less understood.
Purpose of the Study:
- To review literature supporting theoretical predictions for the gynodioecy-dioecy pathway.
- To evaluate the evidence for female fertility advantages and male invasion.
- To assess factors influencing the transition from gynodioecy to dioecy.
Main Methods:
- Literature review of studies on the gynodioecy-dioecy pathway published in the last 5 years.
- Analysis of empirical evidence for theoretical predictions regarding male and female fertility advantages.
- Examination of genetic and ecological factors influencing sex determination and evolution.
Main Results:
- Females consistently show greater seed fertility advantages, positively correlated with female frequency.
- Males demonstrate advantages over hermaphrodites in subdioecious species, as predicted.
- Limited evidence exists for increased male traits in hermaphrodites with high female frequency.
Conclusions:
- While female advantages are well-supported, the transition to dioecy requires further investigation.
- Understanding male fertility evolution and ecological factors is crucial for a complete picture.
- The study highlights gaps in knowledge regarding the later stages of the gynodioecy-dioecy pathway.
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