system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Is there an actual reason no two people have the same fingerprints, or are there just so many possible fingerprints that it's very unlikely?
gpt
Fingerprints are made when the fingers form in the womb.  When this occurs, multiple layers of tissue are growing at the same time.  However, slight variations in the movement of the layers induces folding, leading to the ridges that make up the fingerprint.  As a result, the exact pattern that ends up on someone's fingers is effectively random.  Theoretically, 2 people could probably have had similar enough conditions in the womb where their fingerprints are the same, but the odds of that are so incredibly low that it's estimated as a 0% chance.