How do human fingerprints form?

Fingerprint patterns develop during fetal growth, shaped by genetics and the physical conditions in the womb. As the skin on the fingertips expands, it forms ridges, loops, whorls, and arches. Small differences in pressure, position, and growth mean even identical twins do not have exactly the same prints. These patterns help improve grip and are useful in touch, though their exact biological purpose is still studied. Fingerprints became important in forensic science in the late 19th and early 20th centuries, especially after the work of Sir Francis Galton and others.