why the '.' in the title ?

It's a period piece.

/ Sorry. I'm sure you're right. It's something an English major would have lost sleep over. It's an interesting question. However, I checked online and while others have noted it, no one seems to have explored the issue in depth.

I noted that an online version of the shooting script was published in 2002 and included the period on the cover but not on the cover of the "shooting script".

Perhaps it's just another irony. The movie talks about adaptation and Charlie wants to show the adaptation of living things from the very beginning of life up to the present. It's a neverending process. But a movie adaptation is a one-time thing that never changes once it's done. Since he's so critical of "the industry" (don't say that!), maybe he's pointing out the silliness of the word.

Perhaps this is an overly simple explanation, but I thought it may just be to signify that that is the finished script made into film. You know, because so much of the film revolves around Kaufman worrying he'll never finish the script the way he wants it. It just made me think of that incredible moment when you type/jot down that last full-stop after writing a brain-scrambling essay.

"I would never want to belong to any club that would have someone like me for a member."

"It feels right. Conclusive."

Maybe it's a send up of titles like Se7en?

--
It's not "Sci-Fi", it's SF!

"Calvinism is a very liberal religious ethos." - Truekiwijoker

Because it's Adaptation, period.

Clerks is the same way. Puzzling