Abstract
Understanding how individual differences among organisms arise and how their effects propagate through social groups are fundamental questions in behavioral biology. Genetic variation among social partners can influence individual phenotypes, creating individual differences that might then have cascading effects in social groups. Using a clonal species, the Amazon molly (Poecilia formosa), we test the hypothesis that such indirect genetic effects (IGE) propagate beyond individuals that experience them firsthand. We tested this hypothesis by exposing genetically identical Amazon mollies to social partners of different genotypes, and then moving these individuals to new social groups in which they were the only member to have experienced the IGE. We found that the differences in aggression experienced in genetically different social environments carried over into new social groups to influence the exploratory behaviors of individuals that did not directly experience the previous social environments. Our data reveal that IGE can propagate beyond the individuals that directly experience them in Amazon mollies and possibly in many group-living species. Theoretical and empirical expansion of the quantitative genetic framework developed for IGE to include cascading and other types of carry-over effects will facilitate understanding of among-individual variation, social behavior and its evolution.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
Data archiving All data will be archived in Figshare upon acceptance.