By comparing the patterns of evolution in the coding and upstream noncoding regions of yeast ribosomal protein (RP) genes duplicated in a genome duplication, we find that although nonsynonymous sites in the coding sequences show strong evidence for the fixation of recent gene conversion events, similar patterns are less evident among the synonymous positions and noncoding regulatory elements. This result suggests a potential explanation for the somewhat puzzling fact that duplicated RP genes are not functionally redundant despite their very high protein sequence identity. An analysis of the patterns of regulatory network evolution after genome duplication also indicates that the duplicated proteins have diverged considerably in expression despite their similar protein sequences.