Summary: Journal of Heredity 2010:101(Supplement 1):S142S157
Ó The American Genetic Association. 2010. All rights reserved.
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Genetic Architecture and the Evolution
ROLF LOHAUS, CHRISTINA L. BURCH, AND RICARDO B. R. AZEVEDO
From the Department of Biology and Biochemistry, University of Houston, Houston, TX 77204-5001 (Azevedo and
Lohaus); and the Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3280 (Burch).
Address correspondence to Ricardo B. R. Azevedo at the address above, or e-mail: firstname.lastname@example.org.
Theoretical investigations of the advantages of sex have tended to treat the genetic architecture of organisms as static and
have not considered that genetic architecture might coevolve with reproductive mode. As a result, some potential
advantages of sex may have been missed. Using a gene network model, we recently showed that recombination imposes
selection for robustness to mutation and that negative epistasis can evolve as a by-product of this selection. These results
motivated a detailed exploration of the mutational deterministic hypothesis, a hypothesis in which the advantage of sex
depends critically on epistasis. We found that sexual populations do evolve higher mean fitness and lower genetic load than
asexual populations at equilibrium, and, under moderate stabilizing selection and large population size, these equilibrium
sexual populations resist invasion by asexuals. However, we found no evidence that these long- and short-term advantages
to sex were explained by the negative epistasis that evolved in our experiments. The long-term advantage of sex was that