Star Trek: 10 Things You Didn't Know About Odo
5. Family Tree (And Flowers, And Rocks)
For all of seasons one and two of Star Trek: Deep Space Nine, Odo was on the 24th century equivalent of Who Do You Think You Are? Or, if they had gone with "horrible smell," more like, Who Does He Stink He Is? Odo's search for his origins ended in The Search, Parts I & II. His family tree was, quite literally, also the family tree, and anything else in that garden into which the Founders fancied a shapeshift. If only they'd all spent less time conquering and more time being flowers and/or a rock!
According to Ira Steven Behr in The Fifty-Year Mission: The Next 25 Years, the roots of Odo's… roots grew somewhat spontaneously out of a "crazy idea" Michael Piller presented one day. "You're all going to think I'm nuts," Piller reportedly told fellow writers/producers. "What if the Founders turn out to be shapeshifters?" Lunch was then had with René Auberjonois to "clue him in". The rest was the genealogy of the Great Link.
Auberjonois did have a few reservations about the big reveal, as he also noted in The Fifty-Year Mission:
When I first read the pilot script, even though Odo's character was quite sketchy, the fact that he didn't know where he was from [..] was what was most fascinating to me. When they told me we were going to find out, I was concerned about where the character would go.
In the end, however, Auberjonois "was satisfied by the solution".