The Komodo dragon is believed to have evolved from an ancestral monitor lizard. Monitor lizards are a diverse group of lizards found in various parts of the world, and they are all closely related. Komodo dragons are estimated to have originated from Australia around 15 million years ago and dispersed to the islands of Indonesia when the sea levels dropped, allowing land bridges to form between the islands. As the Komodo dragons inhabited their new environment, they adapted and underwent evolutionary changes, leading to the unique species we know today.