title: On measuring selection in experimental evolution.
abstract: Distributions of mutation fitness effects from evolution experiments are available in an increasing number of species, opening the way for a vast array of applications in evolutionary biology. However, comparison of estimated distributions among studies is hampered by inconsistencies in the definitions of fitness effects and selection coefficients. In particular, the use of ratios of Malthusian growth rates as 'relative fitnesses' leads to wrong inference of the strength of selection. Scaling Malthusian fitness by the generation time may help overcome this shortcoming, and allow accurate comparison of selection coefficients across species. For species reproducing by binary fission (neglecting cellular death), ln2 can be used as a correction factor, but in general, the growth rate and generation time of the wild-type should be provided in studies reporting distribution of mutation fitness effects. I also discuss how density and frequency dependence of population growth affect selection and its measurement in evolution experiments.
authors.affiliation: Division of Biology, Imperial College London, Ascot SL5 7PY, UK. chevin@imperial.ac.uk
authors.forename: Luis-Miguel
authors.initials: LM
authors.lastname: Chevin
mesh_terms: D005075:Biological Evolution; D005838:Genotype; D008954:Models, Biological; D011157:Population Dynamics; D012107:Research Design; D012641:Selection, Genetic
references.citation: BMC Evol Biol. 2002 Oct 30;2:19
references.pmid: 12443537
references.citation: Philos Trans R Soc Lond B Biol Sci. 2010 Jun 27;365(1548):1975-82
references.pmid: 20478892
references.citation: Proc Natl Acad Sci U S A. 2004 Jun 1;101(22):8396-401
references.pmid: 15159545
references.citation: Genetics. 1972 Oct;72(2):335-55
references.pmid: 4630587
references.citation: Science. 2007 Aug 10;317(5839):813-5
references.pmid: 17690297
references.citation: Genetics. 2001 Oct;159(2):441-52
references.pmid: 11606524
references.citation: Genetics. 2004 Oct;168(2):1009-18
references.pmid: 15514071
references.citation: Evolution. 2006 May;60(5):893-907
references.pmid: 16817531
references.citation: Nature. 1996 Jun 20;381(6584):694-6
references.pmid: 8649513
references.citation: Genetica. 2002 Aug;115(3):283-7
references.pmid: 12440568
references.citation: Genetics. 2007 May;176(1):441-53
references.pmid: 17339222
references.citation: Genetics. 2004 Jun;167(2):815-26
references.pmid: 15238530
references.citation: Evolution. 2000 Feb;54(1):13-20
references.pmid: 10937178
references.citation: Evolution. 1990 Nov;44(7):1725-1737
references.pmid: 28567811
references.citation: Nat Genet. 2006 Apr;38(4):484-8
references.pmid: 16550173
references.citation: Proc Natl Acad Sci U S A. 2001 Jan 30;98(3):1113-7
references.pmid: 11158603
references.citation: Science. 2006 Apr 7;312(5770):111-4
references.pmid: 16601193
references.citation: Evolution. 1985 Jan;39(1):24-40
references.pmid: 28563655
references.citation: Genetica. 1998;102-103(1-6):349-58
references.pmid: 9720287
references.citation: Nat Genet. 2007 Apr;39(4):555-60
references.pmid: 17369829
references.citation: Nat Rev Genet. 2005 Feb;6(2):119-27
references.pmid: 15716908
references.citation: Nat Rev Genet. 2007 Aug;8(8):610-8
references.pmid: 17637733
references.citation: Genetics. 2009 May;182(1):277-93
references.pmid: 19279327
references.citation: Nature. 2009 Oct 29;461(7268):1243-7
references.pmid: 19838166
references.citation: Evolution. 2009 Aug;63(8):2164-71
references.pmid: 19473394
references.citation: Nat Rev Genet. 2002 Apr;3(4):252-61
references.pmid: 11967550