Every person's unique facial features may have been influenced by what their mother ate during pregnancy, a study found - with protein-rich diets leading to wider noses and jaws. Subtle differences in the way people look, from the shape of their skull to the amount of cartilage in their nose, are created in the womb by genes triggered by nutrition. The more protein that is consumed during pregnancy, the more active these genes, known as'mTORC1', become. Researchers say this can'fine-tune' a baby's facial appearance by tweaking the length of the nose and width of the nostrils, the shape of the cheeks and the prominence of the jaw. While the basic appearance of a human face is determined by the parent's genes, siblings often look quite different, and even'identical' twins are never quite the same.

Pigs could be issued with biometric passports based on facial recognition technology, giving farmers a more practical and welfare-friendly way of identifying individuals than ear notches or tags, the current industry standards. Identifying pigs based on their unique facial features could enable them to receive individualised food and veterinary care, and be traced as they go through meat processing.