Alignments were constructed by using MUSCLE (24) with a maximum of 64 iterations. (For detailed analyses, see http://cegg.unige.ch/picornavirus.) Multiple FastA was converted into PHYLIP format (for tree building) with the EMBOSS program Seqret (25) . Trees were built with PhyML (26) by using the general time reversible model, BIONJ for the initial tree, and optimized tree topology and branch lengths. Trees with <50 species and larger trees used 16 and 8 rate categories, respectively. Transition/transversion ratios, proportions of invariant sites, and shape parameters of the γ distribution were estimated.