Meeting Abstract

37.10  Tuesday, Jan. 5  Sexual Dimorphism Increases Evolvability in a Computational Model of a Genetic Regulatory Network FIERST, Janna L; Florida State University jfierst@bio.fsu.edu

The majority of work on genetic regulatory networks has focused around environmental and mutational robustness, and much less attention has been paid to the conditions under which a network may produce an evolvable phenotype. Understanding evolvability, or the ability to produce potentially adaptive variants, is significant because underlying genetic architectures that confer higher evolvability will result in phenotypic traits that respond rapidly to selective pressures. Sexually dimorphic characters often show rapid rates of change over short evolutionary time scales and while this is thought to be due to the strength of sexual selection acting on the trait, it may be that a dimorphic character with an underlying pleiotropic architecture influences the evolution of the regulatory network and results in higher evolvability. I tested this with a computational model of a genetic regulatory network and found that sexually dimorphic characters had higher robustness to mutation, purged deleterious mutations more quickly and had higher evolvability in novel environments. These results indicate that producing two pleiotropically linked characters does not constrain either the production of a robust phenotype or the response to selection. Instead, the genetic system evolves to maximize both quantities. Separate from any kind of sexual selection, the underlying genetic architecture of sexually dimorphic characters may confer a rapid response to selective pressures.