Linking micro and macroevolution in the presence of migration

Area of Science:

• Evolutionary Biology
• Macroevolutionary Patterns
• Quantitative Genetics

Background:

• Macroevolutionary patterns are key to evolutionary biology, involving divergence from microevolutionary processes like subpopulations evolving towards different phenotypic optima.
• Traditional models of macroevolution often overlook migration's role within species, focusing instead on directional selection.
• Understanding the interplay between stabilizing selection and migration is crucial for accurately modeling phenotypic evolution.

Purpose of the Study:

• To reconcile microevolutionary and macroevolutionary processes by incorporating migration into speciation models.
• To develop an Ornstein-Uhlenbeck (OU) model that accounts for decreasing migration during speciation.
• To investigate the impact of migration on trait evolution, phenotypic disparity, and niche filling across phylogenies.

Main Methods:

• Introduction of an Ornstein-Uhlenbeck (OU) model incorporating time-dependent migration between subpopulations during speciation.
• Analysis of trait mean evolution and phenotypic disparity along phylogenies using the developed model.
• Development of a method for jointly estimating selection and migration from time-series data.

Main Results:

• Ignoring migration in time-series data significantly biases the estimation of selective forces.
• Migration decreases expected phenotypic disparity between species, particularly in niche-filling scenarios.
• The developed model extends microevolutionary quantitative genetics principles to macroevolutionary scales.

Conclusions:

• Accounting for migration is essential for accurate inferences at both microevolutionary and macroevolutionary scales.
• Failure to consider gene flow can lead to significant biases in understanding evolutionary processes.
• The study provides a novel framework for integrating migration into macroevolutionary research.