Why does the movie "Adaptation." have a period in its title?

Adaptation is an adaptation of the nonfiction book The Orchid Thief and is a "metafilm".

Adaptation. is a 2002 American comedy-drama metafilm directed by Spike Jonze and written by Charlie Kaufman. The film is based on Susan Orlean's non-fiction book The Orchid Thief, with numerous self-referential events added.

The self-loathing Charlie Kaufman is hired to write the screenplay adaptation for Susan Orlean's The Orchid Thief. Kaufman is going through depression and is not happy that his twin brother, Donald, has moved into his house and is taking advantage of him. Donald decides to become a screenwriter like Charlie and attends one of Robert McKee's famous seminars. https://en.wikipedia.org/wiki/Adaptation_(film)

So the title reflects several things relating to a multifaceted approach to the word, adaptation, because that is what the film is about:

1. A story about a screenwriter adapting someone else's thought to be ludicrous story (Frame Story: a story within a story, Meta Frame Story: based on a book, based on an article). So it in part relates to writers writing about other writers works or experiences in various formats and their experiences writing vs what really happened.
2. The questioning of what a good writer is, as the title is either incorrect or non conventional by having the period.

3. A metaphorical full stop, as the film is about quests for finding meaning in life and could also be seen as a metaphor for writers block. (Main character Charlie has this)

4. Adaptation Pun - A writer adapting another written work, based on a story about the nature and survival of Orchids, while examining human nature's adaptation to change, including the notion of competition in natural selection. (Note the title is also in green and features a fallen over plant).

The film is not only about the experience of the writers searching for meaning in life in order to write the most amazing thing (ie: taking credit), but also examines the differences between what gets written vs what the actual experience were and therefor, it scopes out to both the natural reactions to the experiences the characters have and/or the reality that a writer in many fields are subjugated to certain truths held by industry standards. In other words, it showcases the struggle of subjugation itself and so the period is then proof of this notion and/or an ironic conceit in that surely there is more story to tell.

It's a movie about screenplays. And good screenplays have good punctuation. Period is usually not used in titles or headlines because they should lead eyes to the article or poster.

But in this case it's not only a nod to the topic of the movie but also a FULL STOP. and what is a Full stop in the context of this movie? You need to figure it out.