rate r (in units 
 of substitutions per site per year) &#160;that is used throughout the 
 tree. For every node in the tree whose relative height (in units of substitutions 
 per site) is h, the divergence time of the node will be set to h/r.</p>
<p>Both of these options are only available from the Tree Explorer window 
 when displaying a RelTime tree has been generated without using calibration 
 constraints. To access this utility in the Tree Explorer window, select 
 an internal node or a branch to focus