Pervasive positive selection on duplicated and non duplicated vertebrate protein coding genes
Abstract
A stringent branch-site codon model was used to detect positive selection in vertebrate evolution. We show that the test is robust to the large evolutionary distances involved. Positive selection was detected in 77% of 884 genes studied. Most positive selection concerns a few sites on a single branch of the phylogenetic tree: less than 2.5% of sites are affected by positive selection. No functional category was over-represented among genes under positive selection. Surprisingly, whole genome duplication had no effect on the prevalence of positive selection, whether the fish specific genome duplication or the two rounds at the origin of vertebrates. Thus positive selection has not been limited to a few gene classes, nor to specific evolutionary events such as duplication, but has been pervasive during vertebrate evolution.
Footnotes
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- Received February 4, 2008.
- Accepted June 5, 2008.
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This manuscript is Open Access.
- Copyright © 2008, Cold Spring Harbor Laboratory Press
