There seems to be an "issue" in 0.7.7a with cut and paste.
Try reading in the GenBank sequences from the sequence tutorials.

Select PBI101TD.
Cut
Select X52331
Paste
PBI101TD gets pasted, replacing X52331.

In GDE, the behavior, I think was to insert the pasted sequence at the site of selection, pushing the others
down one row. If all sequences are deselected, the paste is done below the bottom sequence.

I can see that the "right" way to do this is to make a
New sequence, and past into the new sequence. However,
people are used to pasting into an insertion point in text documents, and we have no way of specifying that in bioLegato. It didn't immediately occur to me that I needed to create an empty sequence as a target for a paste. This becomes especially
inconvenient if I want to cut and paste a block of sequences.

One possibility is to prompt the user, asking if they really want to overwrite the target sequence. However,
I am finding it hard to imagine a situation in which
one would want to overwrite one sequence with another. By the same token, it is potentially dangerous to past over
an existing sequence if you didn't expect it.

My suggestion then is to go with the GDE style behavior of pushing the others "down" from the insertion point. And if you really want to delete sequences, that's done
as a deliberate cut step.

Can you think of a better way?