CodeML analysis of mitochondrial protein-encoding genes (13 genes) and evidence of positive selection of cox1, cyt b, nd4 and nd5 in flying insects.

*Branch 2 and branch 3 represent the LCA of Pterygota and LCA of Neoptera, respectively.*分支2与分支3分别代表有翅亚纲（Pterygota）的最近共同祖先（Last Common Ancestor，缩写LCA）以及新翅亚纲（Neoptera）的最近共同祖先。