Genetics of Heroes

Before I start my rant, I'd like to note that I enjoy watching Heroes. I'm a sucker for stories with seemingly ordinary-joe protagonists who have to both come to terms with their new abilities and are unexpectedly sucked into adventure and intrigue. I also think there should be more TV shows that feature sexy and intelligent geneticists. What annoys me about the show is the human genetics/evolution wrapper to the story.

First a bit of background. Chandra Suresh is arguably one of the most important characters in the series, even though he dies before the first episode. As a genetics professor in India, he studied people with extraordinary abilities and came up with a "crazy idea" to explain their origin. He published his hypothesis in a book called Activating Evolution. His obsession cost him his professorship, but he chose to move to New York and work as a cab driver to continue his research. He is killed as he is driving his taxi, and his son Mohinder, who also happens to be a geneticist, takes over his father's work. The first tie-in graphic novel, Monsters (pdf), tells the Suresh family's story.

When Mohinder comes to New York, he discovers his father had assembled a map showing where all the people with superpowers ("extraordinaries") live. The episode before last he explained to an FBI agent how it was assembled: the map shows individuals his father discovered have a "shared genetic marker" and they were "mapped and tracked by the human genome project". In the last episode, Mohinder gives a similar explanation to Nathan Petrelli: the people with special powers all "carry the same gene marker".

That's when I started shaking my fist at the screen (metaphorically) and exclaiming that the plot device makes no sense to me. Let me explain why.

1. All of the "extraordinaries" carry the same genetic marker with a different DNA sequence.
When the creators were asked about the "genetic marker", they confirmed that all of the people with superpowers carry a single unique stretch of DNA.

The show has mentioned a "genetic marker" several times. Is this something found in a person's DNA, is it a formula that takes into account other factors, or something else entirely?

As far as we know right now, there is an arrangement of start and stop codons that our people have that indicates their potential for having an ability. And so far everyone on the list seems to have that marker. But that may be just one piece of the puzzle.

First off, we need to figure out what is meant by a "genetic marker". In the simplest terms, a genetic marker is a segment of DNA whose inheritance can be tracked. Based on the what the creators have said, the superhero marker is a gene that encodes a protein, since it has a "start codon", which is a sequence of three bases that tells the protein-making machinery in the cell where code for the protein sequence begins, and a "stop codon" which tells the machinery where the code for the protein ends.

What we don't know is whether the gene is unique to the "extraodinaries" or if it's a variant of a gene even "normals" carry. However, in the last episode, Mohinder explains that Pete Petrelli can take on other's powers by "resequencing" of his DNA . So there is a common genetic marker, but the exact DNA sequence varies from individual to individual, and that DNA sequence is what gives our heroes supernatural powers. That suggests to me that the genetic marker is actually a new human gene, with a variety of alleles. The addition of new genes is a process termed horizontal gene transfer, and can be caused, for example, by the incorportation of genetic material from bacteria or viruses into humans (technical article: Belshaw et al. 2004) or by genetic engineering. I assume the series will eventually explain how this genetic marker appeared in unrelated people all over the world.

So what's my problem? I can suspend disbelief and accept that there is a gene that allows characters to defy the a law of physics - that's the premise of the story, after all. But it's harder to believe that there is a gene that gives people the ability to defy the laws of nature in different ways - one person can time travel, another can fly, another can heal any wound, and yet another can read minds. Young Micah appears to have inherited the gene, but his skill (controlling electronics) has nothing to do with the powers of his mother (split personality with superhuman strength) or his father (ability to pass through solid objects). If there is going to be a "scientific" explanation, why can't there be some logic to it?

2. The people who carry the genetic marker were found using the Human Genome Project.

When Mohinder claimed the Human Genome Project (HGP) was used to "map and track" the individuals carrying the unique "genetic marker", I think I actually cried out WTF!. The creators of the show apparently think everyone's DNA is freely available for analysis:

And when will we find out what factors are entered into the program that will generate a list like that? Did Mohinder's father have access to a huge DNA database?

Human Genome project. Genetic Migration databases. W.H.O. access points. These are all public databases for researches working in genetics.

Perhaps Heroes takes place in an alternative universe where the HGP actually has the genomic DNA sequence of every person in the world , but in the universe we live in that isn't even close to reality. The sequences released by the HGP are actually a composite of 24 different individuals, so analyzing that data alone wouldn't help you locate a genetic marker that is found in only a small number of people. Of course Chandra Suresh could have used data from the HGP as a starting point to map the superpower gene, but he would have had to collect samples and sequence the DNA from "extraordinaries" himself. Perhaps a maverick geneticist who is apparently a pariah at his university for his unorthodox scientific views would be able to convince strangers from all over the world that he should analyze their DNA, but I find it extremely unlikely.

OK, even if I buy the premise that a unique genetic marker that confers a variety of superpowers suddenly appears in people all over the world, and is discovered by a lone geneticist, it still leaves leaves the aspect of the Heroes "science" backstory that irritates me the most:

3. The superpower genetic marker has something to do with evolution.
This comment by producer/director Greg Beeman illustrates exactly what is wrong with Heroes' take on evolution:

What is your favorite part of the Heroes concept?

The exploration of human beings evolving 'of humanity going to the next level of evolution and the 'how, why, why now' questions that stirs up.

OK, here's the problem: there are no "levels" of evolution. Evolution has no direction. It's no wonder that Chandra Suresh's colleagues dismissed his ideas after he published the book Activating Evolution; his hypothesis that the superpower mutation has created an advanced "evolved human" demonstrates a serious lack of understanding of basic evolutionary biology.

That's not to say that humans have stopped evolving. Even now the human population is slowly changing. Here's the thing: unless the superheroes out-breed us "normals" (or kill us all off) their special genetic marker will never exist in more than a tiny fraction of the population.

I suspect our heroes are more likely an evolutionary dead end than the future of humanity. Nonetheless, I'll be watching when Monday rolls around.

For more on the similar topic, see the "Evolution and X-Men II" powerpoint presentation from "When Good Biology Goes Bad at the Movies.