# How is it possible that every single person has a completely unique and different fingerprint, how are we not running out of unique motifs.

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How is it possible that every single person has a completely unique and different fingerprint, how are we not running out of unique motifs.

In: Biology

Math. The number of combinations grows extremely quickly when you add more options. There are more ways to sort a regular poker deck than there are atoms in the universe.

Even if you make simplifying assumptions and call fingerprints the same when they just share a similar structure you’ll easily end up with billions of possible fingerprints.

If you look at the details more closely (the so-called minutiae, stuff like where exactly one of the line splits into multiples) there are more possible fingerprints than there are possible DNA Strings, practically infinite infinite depending on your measurement precision.

The amount of possible permutations or combinations of a thing can be really, really, really high, with only a small number of actual “things” that can be permuted. The classic example is a deck of cards. There are only 52 cards, but the number of different combinations you can have is so high, that any time you truly randomly shuffle a deck of cards, then it is almost mathematically impossible that any deck of cards, anywhere, EVER has ever been in that order before, or will be again, in the entire past and future history of the universe.

The formula for that is 52!, if you’re interested reading more (the exclamation mark is part of it).

Now consider something like a fingerprint. Its not connected to your DNA at all, it grows and self-assembles randomly in the womb. Even identical twins will have unique fingerprints. And if you think about how many intricate little lines and swirls and spirals and patterns there are that make up a fingerprint, it seems like it’s probably a LOT more than 52, hey?