Fig. 7

a Evolutionary scenario of chromosome structures along the small tree. The following events are shown on edges: −1, loss of one of two paralogs of gene psbY; +1, emergence of a paralog of gene psbY; +R, emergence of an inverted repeat of a chromosome segment; I1, inversion of a chromosome segment; T1, transversion of a chromosome segment; T2, translocation of a chromosome segment; I2, insertion of a chromosome segment, and D – disappearance of a chromosome segment. The number of the events is given in parentheses when greater than 1. For the reconstruction details, see Table S3a in Additional file 1, #3. b Evolutionary scenario of chromosome structures along the large tree. The following events are shown on edges: −1, loss of gene psbY; −2, loss of one of two paralogs of gene rpoC2; +2, emergence of a paralog of gene rpoC2; +3, emergence of a paralog of gene clpC; I1, inversion of a chromosome segment; T1, transversion of a chromosome segment; T2, translocation of a chromosome segment; 2 F, fusion of two paralogs of gene rpoC2 into one large gene, and D, deletion of a chromosome segment. The number of the events is given in parentheses when greater than 1. For the reconstruction details, see Table S3b in Additional file 1, #3