Gattaca (1997) - "You Could Go Anywhere with This Guy's Helix Tucked Under Your Arm"

Spoiler Level – Moderate

The Movie – In a futuristic dystopia where your fate is entirely determined by your genes and nearly everyone is genetically engineered, Vincent is born the traditional way. He needs to borrow the genetic identity of one of the society's elite in order to pursue his dreams.

This is actually one of my favorite movies. It displays the power of genetics while providing important warnings. Scientists have a responsibility to use the power of genetic engineering ethically. And everyone has the responsibility to understand science well enough to prevent those in power from using bad science to justify discrimination.

The Scene – One topic I want to discuss is the limits of genetic engineering, and this is best illustrated by a scene where Vincent's parents meet with a geneticist to make sure their second child is properly engineered. They use in vitro fertilization to create several embryos and select the one with the desired sex, cosmetic and personality traits, and lack of predisposition to inheritable diseases.

Can you tell which is the athlete and which is the musician? No one else can either. From Gattaca.

I also want to talk about the limits of genetic determinism, the concept that your genes alone are enough to determine everything you are and everything you're capable of. This is part of the movie's major theme and is not limited to any one scene.

The Science – The type of genetic selection Vincent's parents perform is realistic to a certain degree. Even today, parents using in vitro fertilization can choose the sex of their child. Ruling out simple genetic disorders and choosing basic cosmetic traits is also reasonable by this approach. However, this type of selection is limited by the number of fertilized eggs you have to choose from. A woman only produces a few hundred eggs in her lifetime. With such few eggs, you'd be lucky to find your perfect combination of 10 genes. The human genome has over 20,000 genes.

It's understandable to assume that in the future there will be ways around this. For instance, we might be able to manipulate a woman's ovaries to make millions of egg cells. But even then, selecting for more than a few genes would be inefficient. It would be easier to manipulate the eggs artificially. Viruses or very small needles can be used to insert your desired genes into any given egg cell. This is not very different from techniques currently in use to genetically manipulate mice. It's completely possible to think the same could be done in humans in a world with less ethical standards.

Microinjection of new DNA into a fertilized egg. The future is now. From Wikimedia Commons.

Still, even with the ability to control every base of DNA in the genome, there would be more limitations. This gets to my second point: genetic determinism. Sometimes having a certain version of a certain gene will definitely result in a given physical trait. However, this is uncommon. Most traits, particularly ones related to personality and intelligence involve a complex interaction of many genes. It's possible that the relationships are so complex that we can never fully understand them.

And even if we perfectly understood how every version of every gene affected the traits we're interested in, this wouldn't be enough. Personality traits aren't just determined by genes but by the environment. This is the famous nature vs. nurture debate. Despite the name, it's not an either/or question. Biologists agree that most characteristics rely and on a combination of the two and just disagree about what the balance is for different traits. It's because of this that identical twins (who have all the same genes) don't have identical personalities. You might be able to say that statistically someone has a higher likelihood of possessing a certain skill or trait, but a blood test will never tell a person's whole story.

Fixing the Scene – I actually don't think that the movie needs much fixing. The geneticist's dialogue can be altered slightly to indicate that the embryos are being manipulated and not just selected, though that's a minor quibble. The society in Gattaca is wrong to put so much emphasis on genetic determinism, but that's the point the movie is trying to get across. It's unlikely that our society would ever get as extreme as Gattaca, but genetic discrimination already exists to some extent with insurance companies and employers evaluating customers and employees based on their genetic predispositions. In 2008, the US Congress passed the Genetic Information Nondiscrimination Act to combat this, but Gattaca rightly points out how easy it is to get around such laws. So I think it's fair to allow the movie to present a world where genetic determinism is taken to an unreasonable extreme in order to warn us against it.

Next Week – A return to viruses and DNA with a 2010 episode of The Walking Dead.