The Fingerprints That Even Twins Cannot Share

In 2013, forensic scientists at the University of Oxford confirmed what detectives had long observed: identical twins, who share every strand of DNA, still have completely different fingerprints. The ridges and whorls that form on a baby's fingers between weeks ten and seventeen in the womb are shaped by the precise pressure of amniotic fluid, the exact angle of each tiny hand against the uterine wall, the unique rhythm of movement only that child makes.…