currently selected groups of the alignment will be subdivided
according to the contents of the currently selected region. <br />Use
this to subdivide an alignment based on the different combinations
- of residues at marked columns. (since Jalview 2.9)
+ of residues at marked columns. (since Jalview 2.8.3)
</em></li>
<li><strong>Undefine Groups (Control U)<br>
</strong><em>The alignment will be reset with no defined groups.<br>