Tropes in Speculative Fiction

Television Tropes & Idioms is a wiki that focuses on common tropes ("story components or elements which have become standardized through decades (or more) of use") in television, movies, novels, and comic books. It's got a great long list of speculative fiction tropes - and the entries don't just describe the trope, some also explain why the trope is wrong. Here are snippets from a few of their biology-related entries:

• The Adam and Eve Plot: only two members of a race remain to repopulate their species. The problem?
  

  This, of course, ignores real population genetics. A certain minimum number of genetically divergent individuals are needed in a gene pool to maintain a healthy genetic diversity. For humans it is somewhere between 150 and 160. You usually won't find this in direct siblings. More casually, this results in the unspoken implication that said newly propagated species does not have a problem with incest.

• Bizarre Alien Biology: while aliens are humanoid on the outside, their totally different f on the inside
• Brain in a Jar: pretty much what it sounds like
• Cloning Blues: it's not easy being a mere copy
• Evilutionary Biologist: "Some evil mad scientists use their twisted intellect solely for personal gain. This particular villain is not so provincial. His genius and his motives go hand in hand, and his concerns are (he thinks) with the welfare of the human species. Simply put, to the Evilutionary Biologist, humanity is stuck in an evolutionary rut, and it's up to him to put us back on the proper path so we can continue to evolve."
• Evolutionary Levels: Yes, there's evolution in SF, but it's usually depicted incorrectly.
  

  One popular misconception seems to be how the entirety of evolution is preprogrammed, past and future. Evolutionary states that don't exist yet are just waiting in human DNA to be triggered by rather simple means, as opposed to the culmination of little changes brought on by passing down genes over hundreds of generations. Likewise, it's easy to "regress" in evolution. A Mad Scientist or a Negative Space Wedgie for example, can hit humans with rays that will turn them into Neanderthals or monkeys, regardless of the fact that humans evolved from neither. (If they made an effort, this could work, because there is a remotely linear progression of common ancestors for species. So close, and yet, so dumb.)

  Not to mention the love of Lamarckian-style evolution that's caused by environmental change, evolution that affects entire populations simultaneously, and future humans with gigantic heads. And that's how you get Mutants with a capital M.
  
• Genetic Engineering is the New Nuke: in the old days superpowers were created by radiation. Today, genetic engineering does the job.
• Genetic Memories: our genes store the memories of our ancestors
• Half Human Hybrids: despite bizarre alien biology, humans interbreed with a variety of other species. See also No Biochemical Barriers.
  
• Soylent Soy: in the future meat is very scarce . . .
  

Be sure to look at their list of "Applied Phlebotinum" and "Hollywood Science" tropes too.

(via The World in the Satin Bag)

Tags:science fiction, biology, tropes