Adaptive evolution of reproductive and vegetative traits driven by breeding systems

Area of Science:

• Evolutionary Biology
• Plant Sciences
• Quantitative Genetics

Background:

• Inflorescence size is crucial for plant reproductive success.
• Breeding systems may reflect varying mating competition levels, influencing trait evolution.
• Leaf size, a vegetative trait, has been observed to correlate with inflorescence size.

Purpose of the Study:

• To investigate the adaptive evolution of inflorescence and leaf size in the genus Acer.
• To test if breeding systems act as selective scenarios driving trait evolution.
• To determine if reproductive and vegetative traits evolve under the same selective regimes.

Main Methods:

• Comparative analysis of inflorescence and leaf size evolution using Brownian motion and Ornstein-Uhlenbeck (OU) models.
• Modeling trait evolution under different selective regimes linked to mating competition.
• Statistical model fitting to identify the best evolutionary model.

Main Results:

• An OU model with three optima best explained inflorescence and leaf size evolution.
• Trait optima increased with higher levels of mating competition.
• Both inflorescence and leaf size evolved under the same selective regimes and in the same direction, indicating correlated evolution.

Conclusions:

• Adaptive evolution, driven by mating competition, shapes both reproductive (inflorescence) and vegetative (leaf) traits in Acer.
• Correlated evolution of inflorescence and leaf size is supported by the findings.
• Selective pressures on reproductive traits can influence the evolution of associated vegetative traits.