The credits don't mention it but this movie is obviously based on the (new) Twilight Zone episode of the same title from 1989, which was written by Alan Brennert.
Technically its based on the short story of the same name by Tom Godwin and not the Alan Brennert adaptation. I can't remember when the short story was written but it was way before 1989.
The original story can most easily be found in the anthology "Science Fiction Hall of Fame". Each member of the SFWA (Science-Fiction Writers Association) voted for what each considered to be the greatest SF story every. The results were tabulated and anthologized by Robert Silverg, I think in 1966.
This story was so well thought of, it got voted into the anthology.
It's by far the best story I've ever read by Godwin.
Yes, it was written by Tom Godwin back in '54 and not based on a twilight zone episode. I just hope that the woman who is in charge of his estate is receiving royalties from the books that have been stating as it being in. If not then I should tell my Aunt about this. You see, Tom Godwin's my Mother's grandfather. It was a VERY controversial short story for that time period. Then again he WAS a very controversial man. He was married to a Cuban native who was a female radio personality and if you think about how things where back then you'd figure out very easily as to why it was so controversial.