More genes underwent positive selection in chimpanzee evolution than in human evolution.

ABSTRACT: Observations of numerous dramatic and presumably adaptive phenotypic modifications during human evolution prompt the common belief that more genes have undergone positive Darwinian selection in the human lineage than in the chimpanzee lineage since their evolutionary divergence 6-7 million years ago. Here, we test this hypothesis by analyzing nearly 14,000 genes of humans and chimps. To ensure an accurate and unbiased comparison, we select a proper outgroup, avoid sequencing errors, and verify statistical methods. Our results show that the number of positively selected genes is substantially smaller in humans than in chimps, despite a generally higher nonsynonymous substitution rate in humans. These observations are explainable by the reduced efficacy of natural selection in humans because

SUBMITTER: Bakewell MA 

PROVIDER: S-EPMC1863478 | biostudies-literature | 2007 May

REPOSITORIES: biostudies-literature