Fig. 3

Diversity of intraspecific mitochondrial gene rearrangements in Quasipaa boulengeri. a Four types of gene rearrangement in the “WANCY” region. b Types of evolution and putative mechanism of gene rearrangement of the mitochondrial sequences according to the tandem duplication–random loss model (TDRL). TDRL first produces Types I and II. Type II is the intermediate state with two trnA genes. Types III and IV result from the random loss of one alternative trnA. “---”, pseudogenes or noncoding sequence. c Phylogenetic relationships and divergence times of four mitochondrial gene rearrangements in Quasipaa boulengeri. Tree topology derived from BI analyses of cox1 and cob is consistent with an ML tree. Numbers above the lines or beside the nodes are inferred divergence times (Ma) and Bayesian posterior probabilities, respectively. Types II, III, and IV form a clade, and each Type forms its own clade, except for Type III