Using the Ornstein-Uhlenbeck process to model the evolution of interacting populations

Area of Science:

• Evolutionary Biology
• Phylogenetics
• Quantitative Genetics

Background:

• The standard Ornstein-Uhlenbeck (OU) process models phenotypic trait evolution along phylogenies, assuming independent species.
• Realistically, species interact ecologically and exchange genes (gene flow), especially plant populations.
• Existing models often overlook these crucial dependencies, limiting their application to complex evolutionary scenarios.

Purpose of the Study:

• To develop a statistical phylogenetic framework that integrates adaptation and migration for analyzing trait evolution.
• To provide analytical solutions for models incorporating these factors.
• To investigate the impact of migration on evolutionary interpretations, particularly regarding convergent evolution.

Main Methods:

• Development of a novel statistical approach with analytical solutions.
• Incorporation of adaptation and migration into a common phylogenetic framework.
• Conducting a detailed simulation study to assess the effects of ignoring migration.

Main Results:

• The proposed model successfully integrates adaptation and migration within a phylogenetic context.
• Simulation results demonstrate significant adverse effects when migration is ignored.
• Ignoring migration can lead to misinterpretations of convergent evolution due to uncorrected species similarity.

Conclusions:

• The new model offers a more realistic approach to studying phenotypic trait evolution, especially in interacting species or populations.
• It provides a robust framework for understanding local adaptation and the role of gene flow.
• The findings underscore the necessity of accounting for migration to accurately infer evolutionary processes.