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Linkage limits the power of natural selection in Drosophila.

ABSTRACT: Population genetic theory shows that the efficacy of natural selection is limited by linkage-selection at one site interferes with selection at linked sites. Such interference slows adaptation in asexual genomes and may explain the evolutionary advantage of sex. Here, we test for two signatures of constraint caused by linkage in a sexual genome, by using sequence data from 255 Drosophila melanogaster and Drosophila simulans loci. We find that (i) the rate of protein adaptation is reduced in regions of low recombination, and (ii) evolution at strongly selected amino acid sites interferes with optimal codon usage at weakly selected, tightly linked synonymous sites. Together these findings suggest that linkage limits the rate and degree of adaptation even in recombining genomes.

SUBMITTER: Betancourt AJ

PROVIDER: S-EPMC129723 | biostudies-literature | 2002 Oct

REPOSITORIES: biostudies-literature

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Linkage limits the power of natural selection in Drosophila.

Betancourt Andrea J AJ Presgraves Daven C DC

Proceedings of the National Academy of Sciences of the United States of America 20021007 21

Population genetic theory shows that the efficacy of natural selection is limited by linkage-selection at one site interferes with selection at linked sites. Such interference slows adaptation in asexual genomes and may explain the evolutionary advantage of sex. Here, we test for two signatures of constraint caused by linkage in a sexual genome, by using sequence data from 255 Drosophila melanogaster and Drosophila simulans loci. We find that (i) the rate of protein adaptation is reduced in regi ...[more]

PMID: 12370444

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