I don’t normally watch the TV show Scorpion, the pitch meeting for which I imagine included someone saying “Imagine Big Bang Theory was a cop show.” But my girlfriend’s parents were visiting, so I didn’t have control of the remote. Without commenting on the quality of the series as a whole or its likeability, I am pleased to say that the episode we watched gave me the most unintentionally hilarious moment of TV in weeks.
“The Fast and the Nerdiest” episode featured a plotline entwining car races, bioweapons, and something about The Price is Right, because reasons. I would be overselling the attention I paid if I said I could describe the plot in detail, but one moment caused my ears to prick up and earned a hearty bad-science-laugh.
Sly has just stumbled onto an improvised lab. While no one’s home, he finds a red bag with a biohazard label and DNA letters printed on it and gives the camera his best worried face. He’s on the phone with Walt, who is drag racing some gorgeous classic cars– not particularly important, since, hey, classic cars!
Sly: I am looking at biohazard labels with a genome string on it
Walt: Sly, read it aloud to Toby.
Walt: Hold on, back to the CC part
Walt: Toby, you hear what I hear?
Toby: Yes, that whole string is a common cold virus but that CCT runner in the middle, that’s a mitochondrial gene, unique to people of mesoamerican descent
Sly: Like Aztecs found in Balio?
Toby: Yes, exactly like the Aztecs in Balio. This weapon is designed to spread via the common cold, while attaching a specific gene that’s only found in that particular race of people.
This is the spot. This is what got me calculating if there was enough room betwixt my guests and myself to roll on the floor laughing. Please, dear reader, allow me to dissect the… ahem… science in this exchange.
First, the positive: The writers used DNA letters!
Second, the negative: The rhinovirus (common cold virus) has an RNA genome, so the letters aren’t the same. DNA uses ATCG. RNA uses AUCG.
Next, the really negative: A 14-letter stretch of DNA sequence is hugely unlikely to be only found in one strain of one virus that specifically targets one human subpopulation.
In the world of DNA words, size really does matter.
Being a bit of a DNA geek, I took this sequence and did a BLAST search. BLAST is a freely-available web tool that tries to guess what species a bit of DNA came from and specifically what part of that species’ genome. TGCTCCTATCCCGA could come from at least 100 different spots in the genomes of different species. And not one of these hits is from the common cold (rhinovirus).
While any two humans have >90% of the same sequence in the same spot in their genomes, we can differ at millions of places because our genomes are large– 3,400,000,000 letters large. The likelihood of four DNA letters sufficiently distinguishing one POPULATION from another is absurd. We researchers have to keep sequencing thousands of persons’ genomes to figure out the baseline level of difference between populations, and we already have millions of places people differ from each other.
For a show about hackers, they sure missed a great opportunity to show a screen with gobs of information on it. Why not have the biohazard bag with a long, complex string of letters, have Sly take a photo, send it to the team, opening the door to a quick gag about texting-while-driving, and transmitting the data? This source sequence could come from the publicly available databases of cold virus genome sequence.
This choice the writers made seems small, but it could very well affect how people perceive bioweapons and their feasibility. The concept of targeting a specific genetic marker of a population with a virus or other drug is the dream of many a comic book despot, but it’s not there yet. We’re not good at distinguishing populations based on their genes. We need millions of datapoints to classify people even roughly on their backgrounds. Even the commercial genealogy tests based on these millions of datapoints are only good enough to give a score for what percentage of your genes can likely be traced back to one general geographic area.
So this “virus,” with its teeny string of wrong DNA letters would not be able to do much of anything, let alone target a specific population for a nasty cold.