65 Oral - Keynote #4 (Session Chairs) and Awards
Friday June 10, 2:30 PM - 3:00 PM

Author:
Rafael Guerrero

Affiliation: North Carolina State University

Keywords:
Speciation & hybridization

Postzygotic reproductive isolation--manifesting as sterile or inviable hybrids--is often the result of Dobzhansky-Muller incompatibilities, epistatic interactions involving the substitutions accumulated between diverging populations. Previous theoretical work has found that the number of incompatibilities should grow faster than linearly with time, the so-called "snowball effect". In this talk, we develop a gene network framework for the evolution of genetic incompatibilities and explore how underlying properties of the network--topology, density, and size--affect the snowball effect. We find that, while a snowball is generally expected for pairwise genetic incompatibilities, the agglomeration of these incompatibilities into higher-order clusters is more common than previously thought. These findings imply the need to revise some simplifying assumptions about the genetic basis of incompatibilities, and suggest that the buildup of reproductive isolation will not typically track the accumulation of incompatibility loci.