Evolutionary consequences of gender plasticity in genetically dimorphic breeding systems

Area of Science:

• Evolutionary biology
• Plant reproductive strategies
• Breeding-system evolution

Background:

• Understanding the evolution of breeding systems is crucial in evolutionary biology.
• Dioecy (separate sexes) can evolve from hermaphroditism through intermediate stages like gynodioecy (females and hermaphrodites) and androdioecy (males and hermaphrodites).
• Gender plasticity, the ability of an organism to alter its sex expression, is hypothesized to play a role in these evolutionary transitions.

Purpose of the Study:

• To evaluate the role of gender plasticity in the evolutionary pathways leading to and from dioecy.
• To investigate how gender plasticity affects the stability of intermediate breeding systems, such as subdioecy.
• To identify factors influencing transitions between different breeding systems.

Main Methods:

• Review of existing studies on breeding-system evolution in various plant species.
• Analysis of evidence from subdioecious species to assess the occurrence and impact of gender plasticity.
• Comparative evaluation of factors (e.g., reproductive assurance, herbivory, resource availability) influencing transitions to and from dioecy.

Main Results:

• Gender plasticity appears to occur in species evolving along the gynodioecy pathway, stabilizing subdioecy by reducing seed production costs.
• Factors influencing transitions toward androdioecy or reversion from dioecy are diverse, including reproductive assurance, herbivory, and gender plasticity.
• Gender specialization is generally favored in resource-poor environments, irrespective of the specific evolutionary pathway to dioecy.

Conclusions:

• Gender plasticity is a significant factor in the evolution and stability of plant breeding systems, particularly in transitions involving dioecy.
• Environmental conditions, such as resource availability, interact with gender plasticity to shape evolutionary trajectories.
• Further research into gender plasticity can provide deeper insights into the complex mechanisms of breeding-system evolution.