Komodo dragons (a lizard species) and red-tailed boas (a snake species) are both reptiles. They share a common ancestor population that lived about 250 million years ago, but they have been separated in different environments, with different food sources, for millions of years. Komodo dragons and red-tailed boas have some shared structures. They also have some differences in their structures. 1.Why do Komodo dragons and red-tailed boas have some shared structures and some different structures?