In the 1986 remake of The Fly, rogue scientist Seth Brundle believes he has invented a way for humans to teleport between locations. He hopes that his two "telepods" will make it possible, and he thinks that he's getting close to victory. They're not perfect just yet — testing it out with a baboon resulted in the animal being turned inside out — but he's confident enough to try out teleporting for himself.
But his experiment goes horribly wrong. A fly slips into the telepod before Brundle turns it on, and over the following days, he realizes that his DNA has merged with the fly, and he is becoming a human-fly hybrid.
So, if two organisms enter the telepod together, they can merge into one — but this explanation doesn't actually hold up under scrutiny. Technically, the telepod would be full of invisible bacteria as well, and if the machine had the power to combine the DNA of multiple living creatures, Brundle should have become some sort of human-fly-bacteria hybrid — and even grosser than the creature he ends up becoming in the film's final act. A missed opportunity? Perhaps.
