It's a question of movies asking you to believe a scientific event or the product of a scientific process without any explanation. There are exceptions, and Rose uses those in his class to explore science fact and science fiction in movies. If an ant became that big, it wouldn't be able to move about as the insect we know. Very large or small size imposes functional constraints upon organisms. And, bad science in movies can perpetuate science misconceptions, he said.
Mutation is an example.
Mutation is a change in DNA, not an animal or an insect being hit by rays and turning into a monster. Which is not to say science-related movies can't be both explanatory and engaging. Movie plots can also be driven by the accepted scientific ideas of the times, he said. In the early 1800s, one widely held theory was that life was spontaneously generated from dead matter. The first experiments with electricity were also taking place around the same time.