A rooted tree is one in which the root of the phylogenetic tree is determined by using the mid-point rooting In the mid-point rooting method, the root of an unrooted tree is placed at the mid-point of the longest distance between two taxa in a tree.RH_Mid_point_rooting or out-group An out-group is a sequence (or set of sequences) that is known to be a sister taxa to all other sequences in the dataset.RH_Outgroup sequences.