1. Lactose Tolerance
The ability to digest lactose—the sugar found in milk—into adulthood is a fascinating example of rapid human evolution. In most mammals, the gene responsible for breaking down lactose switches off after weaning. However, in populations with a history of dairy farming, a genetic mutation enables lifelong lactose digestion. This trait, known as lactase persistence, has become increasingly common in parts of Europe, East Africa, and the Middle East. Yet, many adults worldwide remain lactose intolerant, illustrating how evolution is still at work across different regions. Read more about this remarkable adaptation.