system
Given the following post, respond as if you're commenting on Reddit:
human
How did we conclude that iris and fingerprints are unique for each and every individual?

It is commonly known fact that no two persons can have the same fingerprints (and iris). But how can we conclude that? What is the research behind this? What are the chances that someone else on this planet in the present, past or future does not have the same biometrics as I do?
gpt
>It is commonly known fact that no two persons can have the same fingerprints (and iris). But how can we conclude that?

It's not that they *can't*, it's just that they're highly unlikely to. And that can be statistically verified. We have huge databases of biometrics so it's easy to check how rare it is for people to have the same fingerprint etc.