Why No Scream Tracks?

Thinking about traditional style sitcoms, I often wondered--where did the "laugh track" come from? At what point did someone watching a television sit com say to themselves "how will I know where the funny parts are if I don't hear others laughing? Oh, television, please guide me!"

I get that live shows would feature laughter from the audience, and perhaps someone at some point decided the audience wasn't laughing enough so maybe they needed to add something. I read somewhere that the actual canned laughter that we hear even today was all part of an original recording from sixty years ago, so who knows what they were laughing at (probably Victor Borge, or some Marx Brothers routine). What is interesting is how it persisted, long after sitcoms were taped. Somehow, though, the use of canned laughter never crossed over into comedy films--when's the last time you heard laughter in a movie theater that was part of the recording?

And why has this not caught on to other genres besides sitcoms? Couldn't we have scary TV shows with piped in screams and gasps from the audience? Couldn't we have clever mysteries (like "Murder, She Wrote") add in some "aha!" from a recording? Couldn't we have pre-recorded groans inserted in CSI: Miami every time David Caruso makes a painfully bad pun?