The evolution of gynodioecy on a lattice

Area of Science:

• Evolutionary biology
• Plant reproductive strategies
• Population genetics

Background:

• Gynodioecy, a breeding system with hermaphrodites and females, arises from mutations affecting pollen production.
• Previous models often overlook spatial dynamics, which are crucial for organisms with limited mobility.
• Understanding spatial effects is key to explaining the prevalence and evolution of different plant breeding systems.

Purpose of the Study:

• To investigate the influence of spatial structure on the evolution of gynodioecy.
• To compare predictions from spatial models with non-spatial (mean-field) approaches.
• To assess the viability of female reproductive strategies under varying spatial conditions.

Main Methods:

• Generalised mean-field analysis (non-spatial).
• Stochastic spatial simulations incorporating local interactions.
• Modeling the evolution of gynodioecy with a dominant nuclear gene for male sterility.

Main Results:

• Mean-field models significantly underestimate the required reproductive advantage for female establishment in spatially structured populations.
• Spatial constraints decrease the likelihood of gynodioecy evolving, especially with localized pollination and seed dispersal.
• Lower frequencies of females are predicted in gynodioecious populations under local interactions.

Conclusions:

• Plant breeding systems are sensitive to spatial structure and interaction range.
• Gynodioecy may be less likely to evolve and persist in species with restricted gene flow.
• Findings have implications for understanding the evolution of dioecy and interpreting empirical data on female frequencies.