Meeting Abstract

P2-64   -   Testing for selection on social behavior genes of birds with lekking and cooperatively courtship behavior Alfonso, CA*; Bolton, PE; Moore, IT; Virginia Tech; East Carolina University; Virginia Tech calfonsoc@vt.edu

Lek-based mating systems, in which males gather to display for females and provide nothing more than their genes, have evolved multiple times in animals. Amongst birds, lekking is displayed in many unrelated species, including the neotropical manakins. There is variation in male courtship behavior exhibited at the lek among manakins, including cooperative courtship displays by Wire-tailed manakins (Pipra filicauda) and Lance-tailed manakins (Chiroxiphia lancelota). Studies have not explored the genetic mechanisms of reduced aggression and increased cooperation in manakins despite the evidence of the role of genes in the social behavior of birds. The goal of this project is to investigate if lekking behavior shows signs of positive selection on the genes associated with aggression and if positive selection could explain the convergence of expressing cooperative behavior in manakins. We explored 16 genes linked to aggression to identify patterns in the genetic sequences of a phylogenetic clade of nine lekking species and two cooperative species within a tree of 18 species. We used branch-site models in the Codeml package of PAML and aBSREL of HyPhy to look for positively selected gene sites in the lekking branch and the two species with cooperative behavior. Codeml and aBSREL found no evidence of positive selection in the 16 genes for either the lekking branch or the cooperative species, and the genetic sequences of those species were relatively conserved. Genes linked to aggressive behavior fulfill vital functions associated with reproduction that might prevent evolutionary changes in their sequence structure. Further, genetic changes that explain the convergent evolution of cooperative species could happen in non-coding regions. Although we found no evidence of positive selection, this study is the first attempt to understand the relationship between genes and the behavior of cooperative lekking birds.