The look-ahead effect of phenotypic mutations.
BACKGROUND
The evolution of complex molecular traits such as disulphide bridges often requires multiple mutations. The intermediate steps in such evolutionary trajectories are likely to be selectively neutral or deleterious. Therefore, large populations and long times may be required to evolve such traits.


RESULTS
We propose that errors in transcription and translation may allow selection for the intermediate mutations, if the final trait provides a large enough selective advantage. We test this hypothesis using a population based model of protein evolution.


CONCLUSIONS
If an individual acquires one of two mutations needed for a novel trait, the second mutation can be introduced into the phenotype due to transcription and translation errors. If the novel trait is advantageous enough, the allele with only one mutation will spread through the population, even though the gene sequence does not yet code for the complettrait. Thus, errors allow protein sequences to "look-ahead" for a more direct path to a complex trait.
Whitehead
Dion J
DJ
Institute for Evolution and Biodiversity, The Westphalian Wilhelms University of Muenster, 48149 Muenster, Germany. dion@uni-muenster.de
Wilke
Claus O
CO
Vernazobres
David
D
Bornberg-Bauer
Erich
E
D000483:Alleles; D003198:Computer Simulation; D019143:Evolution, Molecular; D005828:Genetics, Population; D008957:Models, Genetic; D009154:Mutation / Q000235:genetics*; D010641:Phenotype; D014176:Protein Biosynthesis / Q000235:genetics*; D019655:Quantitative Trait, Heritable; D012641:Selection, Genetic; D014158:Transcription, Genetic