Amino acid evolution in numit RPS13. (A) Alignment of mt RPS13, numit RPS13, nucp RPS13 sequences, and RPS13 from E. coli and Thermus thermophilis. Amino acids in numit RPS13 that are identical to those in mt RPS13 or nucp RPS13 are shown on a black background. Dashes indicate gaps inserted to improve alignment. Red plus signs indicate positions of positively selected amino acids. Black arrows indicate amino acids in numit rps13 in at least one rosid species that have mutated to the amino acid present in all eight mt rps13 genes, summarized in panel B. Panel B also includes a phylogeny of the rosid species and our hypothesized evolutionary timing of each amino acid change. Numbers in panel B indicate positions in the alignment shown in panel A.