Fig. 2.

Evolutionary rates for 50 NAD metabolic enzymes measured as d_n/d_s based on human NAD enzymes and their orthologs in other vertebrate species. Genes that show significant evidence for positive selection based on site test (see Section 2) are boxed in red. Parameter estimates for the site test results are shown in Table 2. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)