Biological incest?

I'm beginning to think this may be too far fetched...i'm writing a story about a college student who ends up sleeping with her professer, who just happens to be her father, but she doesn't know this. Can anyone tell me, is this possible? I've heard of it happening between brothers and sisters, when they have been separated in younger life, and then met up and fallen in love later, but between a father and his daughter?
Basically in the story, the father left the mother when they were both eighteen and she was pregnant, so the daughter has never known him.
And now she's at the college where he works, and is her tutor.
I did a very brief search on the net entitled 'biological incest' and it didn't bring up much. I was loathe to type anything more specific, because lord knows what i would have got!
I am beginning to wonder if i should switch the characters around a bit, making her boyfriend her brother, the professor could still be her dad, but get insanely jealous for some reason...i don't know...all i know is i am insanely stuck!
Apparently there's a theory that the rest of human life after adam and eve had to come from incest.

I don't think it's too far fetched. I think you should go ahead with the professor/father story. Man that's creepy. But it could totally happen. :shock:

okay, maybe you're right...but i keep thinking i need to do some research, like, from case histories or something, because obviously it's something i've never experienced...i've done a search on the net, but i can't seem to find what i'm looking for...
it's like you said, it's creepy, but it's also a heavy subject line...man, i never do anything by halves!