What do you think of this fact?
Identical twins are basically nature’s copy-paste. They come from the same fertilized egg, so they have practically the same DNA. Some look so alike that even their friends mix them up. A fingerprint scanner never would, though.
DNA is only the blueprint
Even identical twins have different fingerprints. That’s because genes don’t decide everything about your prints. They set the rough pattern. That’s why, according to BBC Science Focus, twins’ fingerprints usually look more alike than two strangers’. Experts and recognition software can still tell them apart.
The fine details, like where a line ends, splits or forms a little island, come from somewhere else.
Shaped in the womb
The ridges on your fingertips form, according to BBC Science Focus, between weeks 13 and 19 of pregnancy. During that time, lots of things affect the growing fingers:
- the exact position in the womb
- the length of the umbilical cord
- blood pressure
- nutrition
- how fast the fingers grow
Twins share a womb, but they never lie in exactly the same spot. So every finger grows under slightly different conditions. Those tiny differences are enough to create a unique pattern. Once it’s formed, it stays with you for life.
Randomness with a system
Think of it like two bakers with the same recipe. Both cakes turn out similar, but never identical down to the last crumb. DNA is the recipe, the womb is the kitchen, and every oven runs a little differently.
According to BBC Science Focus, the chance of two unrelated people having identical fingerprints is less than 1 in 64 billion.
So twins share a lot: a birthday, their genes, often even clothes. But each one only gets into their phone with their own finger.