Gattaca is still pertinent 25 years later

Everything you say makes sense, but none of it has to do with eugenics. It has to do with assortative mating. Eugenics is about socially driven desirable trait selection (where a trait can be what kind of family you come from). The social is the most important part. Not the trait selection.

Individual trait selection allows a multitude of traits to thrive. Social trait selection tends not to.

I'm not sure about that, possibly he put some sort of special make-up/glue-ish stuff on his face to try to seal it in, and his clothes caught the rest of it? He's seen putting stuff in his hair, probably for that purpose. Anyway, how sensitive are detectors in real life? Remember, you need enough intact genetic material to figure out who it is, it's not like detecting anthrax or something where you can just look for a few short conserved snippets. I imagine it's not something PCR works especially well on, so you might not be able to amplify it at all.

I'm perhaps in the minority of people here, but I didn't like Gattaca, because I thought it actually didn't approach any of the nuance of the genetics discussion, instead opting for a pretty inane oversimplification. Perhaps it makes for an entertaining movie, but it's not a deep philosophical piece.

In the movie, the "bad guys" believed that your potential is limited by your genetics. Which is trivially true. But, weirdly, the movie decides this is the thing that needs to be disproven, and goes on to show the main character "overcoming his potential", which is, by the definition of the word "potential", not possible. Showing a fictional character swimming faster than he's supposed to be able to doesn't persuade me that people can overcome their potential.

As someone with a disorder which has a genetic component, I don't feel that anyone is doing me any favors by this naive polyanna-ism. There are things I cannot do as a result of my genetics, and it would be good for no one, including me, to assume otherwise. In fact, not understanding my own limitations has been one of the most destructive forces in my life, and identifying and acknowledging those limitations has had immense positive results for me.

And very few people, even among literal eugenicists, believe that genetics are the only thing that determines our potential. Most people understand that both nature and nurture are components of one's potential.

So basically, Gattaca is a movie that disprove something that is true, and that even the bad guys don't believe is the whole picture.

Where the bad guys in the movie go wrong isn't that genetics determine what your potential is (they do), but what to do about it. In the movie, a person's genetics are used to determine all sorts of far-reaching effects about their life.

But if we understand that both nature (genetics) and nurture play a part, then it becomes obvious that just because a person has optimal genetics for a certain trait, doesn't mean they'll actually reach the full potential of that trait. Someone with suboptimal genes for that trait might more fully realize the potential of those genes, and surpass the person with better genes for that trait.

And further, we might some day be able to associate genes with traits to the point where we know what genes are optimal for certain traits, but it would be extreme hubris to think we really understand what traits are optimal for a job or task. At my college the math requirements for a CS degree exceeded the math requirements for a math minor: and I barely ever use above 8th grade math in my almost two decades as a programmer. If we could test genetic predisposition for math ability, testing programmers for those genes would be counterproductive: not because programmers might overcome their potential for math ability, but because math isn't really all that relevant to programming. It's a losing game trying to align these traits better: the needs of jobs change over time, so the genetically-ideal candidate for a job today won't be the genetically-ideal candidate when the job changes tomorrow.

The movie is noticeably sparse in its explanations of how they define "intelligence", for example. And defining "intelligence" is a pretty difficult task.

The real-life bad guys (eugenicists) get this wrong too: certain races have traits that others don't (white people are most susceptible to skin cancer, for example!) but we have no way of weighing the traits of each race against another race to determine that any one race is superior.

And if we get down to my personal belief on this, it's that everyone is worthy of love, full stop (unconditionally). Conditioning your care for another human being on their genetics is the antithesis of that.

That doesn't mean, however, that we should pretend that genetic advantages don't exist. As I shared before, I have some less-than-ideal genes, and that's a real thing I have to consider in my day-to-day, and a real consideration for me should I ever choose to have children. Of course I'm still a valid human with all the rights that come with that. But that doesn't mean I can somehow overcome those genes.

The thing I liked most in some ways about the film is that society is in some ways correct: going to space with a heart defect is a real issue and we already exclude people based on such issues for very real and valid reasons. Yet, we can't help but root for the protagonist who has their dream denied through no fault of their own but instead the choices of their society and parents. Compelling. If taken in a less extreme sense I think it's a good film for reflecting how much much genetics does determine what we can do, even today, and the reality that many of these limits do ipso facto exclude us from our dreams. As much of life is learning to live with this reality as it is striving to achieve our dreams. The film, of course, presents us with a character who cannot live with it (although with limitations not from genetics) and ultimately commits suicide, and another character who achieves their dream but for whom we do not see the possibly morbid consequences as it is the end of the film.