title: Adaptive protein evolution in Drosophila.
abstract: For over 30 years a central question in molecular evolution has been whether natural selection plays a substantial role in evolution at the DNA sequence level. Evidence has accumulated over the last decade that adaptive evolution does occur at the protein level, but it has remained unclear how prevalent adaptive evolution is. Here we present a simple method by which the number of adaptive substitutions can be estimated and apply it to data from Drosophila simulans and D. yakuba. We estimate that 45% of all amino-acid substitutions have been fixed by natural selection, and that on average one adaptive substitution occurs every 45 years in these species.
authors.affiliation: Centre for the Study of Evolution and School of Biological Sciences, University of Sussex, Brighton BN1 9QG, UK.
authors.forename: Nick G C
authors.initials: NG
authors.lastname: Smith
authors.forename: Adam
authors.initials: A
authors.lastname: Eyre-Walker
mesh_terms: D000220:Adaptation, Biological; D019943:Amino Acid Substitution; D000818:Animals; D003198:Computer Simulation; D004330:Drosophila / Q000235:genetics* / Q000502:physiology; D029721:Drosophila Proteins / Q000235:genetics* / Q000502:physiology; D019143:Evolution, Molecular; D017344:Genes, Insect; D008957:Models, Genetic; D011110:Polymorphism, Genetic; D012641:Selection, Genetic
chemical_list: D029721:Drosophila Proteins