The Time Tree tool in the Tree Explorer is used for calculating relative and absolute divergence times for all branching points in the tree. Using the Time Tree tool will produce a time tree with the same topology as the active tree, where MEGA estimates local clock rates and divergence times for all branching points in the tree using the RelTime (see Tamura et al. 2012) method. When using this tool, all divergence time estimates are based solely on the branch lengths in the active tree (MEGA provides a more powerful likelihood-based tool from the Clocks menu on the main MEGA form).
To use the Time Tree Tool in Tree Explorer, select Compute | Time Tree (or click the Time Tree Tool button which looks like a green clock). A dialog asks if you want to provide divergence time calibration constraints. If you click No, then MEGA will compute relative divergence times for the active tree. If you click Yes, the Calibration Times Editor, which provides a simple interface for specifying calibrations on any internal nodes in the tree, is displayed (see Calibration Times Editor for information on how to use it).
Once the Time Tree tool is finished, estimated divergence times and local clock rates can be exported to a text file (File|Export Current Tree (Time Tree)) or viewed in the information window (File|Show Information).
See also