Social Selection and Indirect Genetic Effects in Structured populations

Area of Science:

• Evolutionary genetics
• Behavioural ecology

Background:

• Social selection and indirect genetic effects (IGEs) are key concepts explaining social trait evolution.
• Both frameworks consider individual interactions but differ in their mechanisms: social selection acts directly on phenotypes, while IGEs act on social partners' phenotypes via genotypes.

Purpose of the Study:

• To compare the evolutionary predictions of social selection and IGEs.
• To investigate whether these concepts yield similar evolutionary trajectories.
• To analyze trait evolution in a multi-trait, multi-member model across four social interaction scenarios.

Main Methods:

• Developed a multi-trait, multi-member model to simulate trait evolution.
• Compared evolutionary outcomes under social selection and IGEs.
• Analyzed four distinct scenarios of social interactions.

Main Results:

• Social selection and IGEs can produce similar evolutionary outcomes and group-level selection pressures.
• IGEs can lead to stronger evolutionary effects due to potential feedback loops.
• IGEs, but not social selection gradients, can differentiate evolutionary responses between genotypes and phenotypes.

Conclusions:

• While both social selection and IGEs contribute to social trait evolution, IGEs offer a more nuanced understanding of genetic and phenotypic evolutionary dynamics.
• The potential for feedback loops under IGEs can amplify evolutionary change.
• IGEs provide a more comprehensive framework for predicting evolutionary trajectories, especially when genotype- and phenotype-level responses diverge.