I found the movie version of “Hitchhiker’s Guide to the Galaxy” by Douglas Adams to be very clever and amusing. But the producers of the movie created a short companion video titled “Making of Hitchhiker’s Guide to the Galaxy” (available on YouTube) that contained a bit of bad science in it. It presents the discredited theory of Lamarckism as an explanation for the physical deformities of the Vogons. Briefly stated (and as presented in the video clip below) this is the idea that if you flattened people’s noses by hitting them in the face with a shovel for millions of years, they would then inherit the trait of flattened noses.
Here is the section from the video “Making of Hitchhiker’s Guide to the Galaxy” in which the movie’s director, Garth Jennings, presents this bit a bogus science as the back story for how the Vogons came to be as deformed as they were over a span of millions of years. The Vogons are a clever visual caricature, but their evolution is not very good as a concept in science fiction.
“So do you think that it is safe to assume that the lens of an eye could have first appeared just as a result of a completely random mutation and in fact was not a lens at all. For example it could be just a kind of a protection screen made of transparent cells which allow the light in but don’t allow in any ‘rubbish’? And after millions of iterations with natural selection applied this protection evolved to become a lens.
Do you think it sounds reasonable?”
It sounds reasonable. I’d point out that many creatures get by just fine with primitive light sensors that lack lenses. The animal that I have in mind is the garden slug. It possesses simple light sensors at the end of two stalks. More sophisticated light sensors would be of little use to a creature like this unless it also had a brain sophisticated enough to process the visual information, and a means of locomotion quick enough so that it could then act upon the information. Here is a short video I made showing the movements of a garden slug, illustrating the connection between its problem solving abilities, locomotion, and sensory equipment.