Synergistic epistasis and alternative hypotheses.
Inbreeding generally results in deleterious shifts in mean fitness. If the fitness response to increasing inbreeding coefficient is non-linear, this suggests a contribution of epistasis to inbreeding depression. In a cross-breeding experiment, Salathe & Ebert (2003. J. Evol. Biol. 16: 976-985) tested and found the presence of this non-linearity in Daphnia magna. They argue that epistatic interactions cause this non-linearity. We argue here that their experimental protocol does not allow disentangling the effect of synergistic epistasis from two alternative hypotheses, namely hybrid vigour and statistical non-independence of data.
Trouve
S
S
Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland. sandrine.trouve@ie-zea.unil.ch
Ding
A
A
Goudet
J
J
D000818:Animals; D003621:Daphnia; D004843:Epistasis, Genetic; D005828:Genetics, Population; D006824:Hybridization, Genetic; D007178:Inbreeding; D008957:Models, Genetic; D010641:Phenotype; D012641:Selection, Genetic