Why don’t identical twins have the same fingerprints? New study provides clues

LONDON: No two fingerprints are exactly the same. That’s what makes them so useful for police and smartphones to positively identify people. Previous research has shown genes play a role in how the complex pattern of grooves and bumps on our fingertips form, so why don’t identical twins have identical fingerprints? A new study reveals that three families of signaling molecules—along with slight differences in the shape of the finger and the timing of skin growth—all interact to create our unique variations.“It is a great example of how minor fluctuations … can generate endless variations in a pattern,” says Roel Nusse, a developmental biologist at Stanford Medicine who was not involved in the research.

The uneven surfaces of fingers improve grip and are found in humans and climbing species, such as koalas and chimpanzees. They also help us feel the difference between textures. Fingerprints form relatively early in fetal development, starting around the 13th week of gestation with the formation of indentations in the fingertips called primary ridges.