Spider-Man (2002) - "Genetically Designed Super Spiders"

Spoiler Level – Low

The Movie – After a bite from a radioactive genetically engineered spider, Peter Parker develops spider-like powers and learns how to use them responsibly as a superhero.

It's not a bad movie. I don't love it, and I don't hate it. I kind of prefer my superheros as Saturday morning cartoons, but the Spider-Man movie is fun enough.

As I've previously said, I'm not specifically going to address the feasibility of superpowers. Rather, I'm more concerned with the bad science of origin stories. And while the basic concept used in Spider-Man really isn't too bad, I have some issues with the execution and the imagery.

The Scene – While touring a university lab, "high school student" Peter Parker is bit by spider that a particularly careless researcher has let free. This spider was genetically engineered using "synthesized transfer RNA to encode an entirely new genome combining the genetic information" of three spiders with interesting abilities. That night, tiny spiders crawl around Peter's nerve cells. Small pieces of his DNA (gray) spontaneously disappear and are replaced by spider DNA (red and blue). This turns all of his DNA red and blue. The next morning, he has a set of spider powers.

In the Marvel universe, you only need to replace three of your three billion DNA base pairs to become a super hero. From Spider-Man. 

The Science – Well, first of all, genetic engineering is definitely a step up from radioactivity in terms of a method for gaining superpowers. I'll give the movie that. But it still has some pretty serious problems.

There's some bad jargon to begin with. Transfer RNA is a real thing, but it's not used to transfer genetic material between species. Genes encode the information for proteins, and transfer RNA is used to interpret the information in genes to build a protein. This is just a case of a writer hearing a term that sounded good and not caring about what it actually meant.

It's the scene of Peter's genes being altered that is the real problem. Maybe that's just meant to be a symbolic dream sequence, but if that's the case, Peter has some pretty inaccurate dreams for someone as knowledgeable at science as he's supposed to be. First of all, and I hope this is obvious, getting bit by a spider will not cause tiny spiders to crawl along your nerve cells. I don't care how the spiders are engineered. They will not inject more spiders, smaller than a single cell, into your body.

Microscopic spiders crawling in your brain. I will not be sleeping this week. From Spider-Man.

And as usual, it's the DNA stuff that bothers me the most. The visual of the DNA isn't terrible though. It reminds me of an electron density image. It's difficult to visualize the anything as small as DNA, but showing where the electrons in the atoms and bonds of a molecules are located is a good way to go. In fact, that's what is actually measured in some techniques used to determine a molecule's structure, such as X-ray crystallography, as discussed last week. Color is artificial at this size, so distinguishing the human and spider DNA by color is fine for clarity's sake. Though having all the DNA change color when just a tiny piece of spider DNA was inserted with was strange.

What's worse is how the DNA exchange happens. Parts of Peter's DNA should not spontaneous disappear. This is not a healthy thing to happen. And replacing just a few base pairs of human DNA with spider DNA probably wouldn't do too much. There are cases where changing a very short portion of DNA can have great effect. Usually that effect is just deleterious, but occasionally small changes can have big gain-of-function effects as well. Spiders and humans are so far apart though, that no human gene can be converted to a spider gene just by changing a few bases. There's a more realistic way to introduce spider DNA.

Fixing the Scene – The spider DNA needs to get most of Peter's cells. His spider senses = brain and nerve cells. Improved vision = eyes. Strength = muscles and probably tendons and bone. Wall-crawling = skin. And so on. The DNA needs to be delivered by something that can reproduce and infect all of these cells. There are such creatures that can do this, but tiny spiders are not among them. Certain bacteria are capable, but mostly just in plants. Viruses are the best choice. I'd recommend taking some liberties and using the virus-like T4 phage as the visual inspiration, since it resembles a spider is some aspects.

Artist rendering of the T4 bacteriophage. Now this is what you use to turn someone into Spider-Man! From Wikimedia Commons.

This is also a good system to use because a virus can be transmitted through a bite. The scientists could have taken a spider that lacked the abilities that Peter would eventually get, and they could have infected it with a virus that contains the genes responsible for the traits. This caused their spider to gain the abilities of the other species. And when the engineered spider bit Peter, the virus infected him, causing him to gain the traits as well. (It's actually really unlikely that a virus that could infect spider cells could also infect humans, but we can let that slide.)

Instead of inserting just a few bases of single-stranded DNA, the virus should be injecting full genes (hundreds to thousands of bases) as double-stranded DNA. Some viruses use single stranded DNA or RNA, but it would need to be converted into double-stranded DNA before inserting into the host genome anyway. The genes insert into the host at random positions and do not require the spontaneous loss of a few base pairs beforehand. This is how real life gene therapy works. While of course, gene therapy cannot be used to produce superheroes today, the concept is related enough that I think it's fair game for science fiction.

Next Week – I finally get around to Prometheus, which I first mentioned back in my third post, to discuss biology and space.