Flip

This command changes the cursor to the 'Flip' icon. Then, if you click on an interior branch A branch is a line connecting either two internal nodes to each other or an external node to an internal node in a phylogenetic tree. The length of a branch denotes the genetic distance (e.g., number of substitutions per unit time) between the two taxa it connects., MEGA reverses the order of the lineages defined by this branch A branch is a line connecting either two internal nodes to each other or an external node to an internal node in a phylogenetic tree. The length of a branch denotes the genetic distance (e.g., number of substitutions per unit time) between the two taxa it connects..

The cursor will revert to the arrow if you click on the arrow icon on the left hand side of the Tree ExplorerHC_Tree_Explorer.