Evolutionary tree of vertebrate mitochondrial Cpn60. ML tree of mitochondrial Cpn60 proteins from mammals, chicken, and frog (in roman font) and translated sequences of the related pseudogenes from human, mouse, and rat (in bold-italics font). Highly degraded pseudogenes for which only fragments could be detected were not considered. Human pseudogenes clustered with primate Cpn60 sequences whereas mouse and rat pseudogenes clustered with rodent counterparts, indicating independent evolution of these pseudogenes in these species. For all species abbreviations see legend for Figure 2. The scale bar represents the indicated number of substitutions per position for a unit branch length.