Radiation and three-eyed fish

Could radiation from nuclear power plants or other sources really cause fish to grow three eyes?

Most of us have seen the popular television show, The Simpsons. Amongst the human population of Springfield, the fictional town in which the cartoon is set, we find ‘Blinky’ the three-eyed fish. In the show, Blinky is associated with the town’s nuclear power plant and is apparently intended to warn us about the dangers of radiation. Three eyed fish? Does this sort of thing actually happen near nuclear power facilities – could it?

Within fictional situations such as television shows, movies and books, we encounter living organisms which have been altered in some accidental manner to be different from their ancestors. Generally, these sorts of creatures are called ‘mutants’ - an organism which has had it’s DNA altered. Sometimes, in fiction, these mutants are shown to have ‘super powers’ such as the altered humans found in the X-Men series of movies. However, other films, in particular many made during the 1950’s, show that mutated DNA results in horrible monsters, barely alive, in pain, or dying, roaming the Earth causing trouble. Blinky the fish, meanwhile, appears perfectly happy despite having a third eye.

What is a mutant?

Scientifically speaking, there are a few different causes for mutation – all of which are actually caused by changes to DNA. Most of us know that DNA (Deoxyribonucleic acid) is a molecule which is found within all living things – and that it’s function is to contain a set of instructions, or blueprints, for the reproduction of an organism. When organisms have offspring, part of the DNA from both parents are used to create the child. During sexual reproduction small errors may occur within the offspring’s DNA. Mutation of this type is naturally occurring, in fact, it is necessary for evolution to take place. The process of evolution eliminates mutations that render organisms less able to survive and reproduce in their environment. Therefore a mutation to DNA that creates an organism that can survive better in it’s environment than it’s colleagues makes it more likely that it will live long enough to reproduce – and pass these mutated genes on to it’s offspring as well. In a very real way, all of us humans alive today are part of a long line of successful mutants.

We can see that there are natural and helpful mutations to be found in nature. But what about mutations which are due to radiation? In order to find our answer, we must look deeper into what science has discovered about radiation, cells and DNA.