You can but you have to re-connect the nodes, (Sit on terrain and planet)
Good idea to do it to a disabled population first and then enable the new pop and then move it to you new location ...
or
Copy/paste your population from the node window, re-connect the nodes and then right click in the preview window, copy coordinates and paste in the coordinates you just copied to the coordinate box of your new population (small icon to the right of the coordinate fields)
hope this helps |:)